NEW YORK STATE GEOLOGICAL ASSOCIATION
62nd Annual Meeting
FIELD TRIP GUIDEBOOK
Gary G. Lash, Editor
Department of Geosciences
State University College
Fredonia, NY 14063
State University of New York College at Fredonia
Fredonia, New York 14063
cover: Barcelona Light, Aimee Tourgee
PREFACE AND ACKNOWLEDGEMENTS
On behalf of the Department of Geosciences and the State University College at Fredonia, I welcome you to the 62nd Annual Meeting of the New York State Geological Association. We have attempted to provide you with a variety of trips that display the geological diversity of western New York. The trips run the gamut from oil and gas exploration to glacial and coastal processes to paleoecological and paleoenvironmental considerations of various stratigraphic units exposed in western New York and ontario.
I wish to thank the field trip leaders and particularly those who made life easier by submitting their manuscripts on time. Mr. Jack Ericson of the College Archives provided the cover figure of Barcelona Light. I am grateful to Nancy Jagoda, our department secretary, for her invaluable assistance in this undertaking. Fredonia state students Blaine smith, Kurt Schober, Kevin McGovern, and Richard Newman assisted in all phases of preparation of the guidebook. Eileen and Jocelyn Lash, Walther Barnard and Jason David Pacos helped to print and collate various chapters of the guidebook. Last but certainly not least, Janet Wentz, Tom Gestwicki and Dave Lillie of the campus Printshop provided valuable technical assistance as well as much needed space.

SatA: DEVONIAN STRATA AND PALEOENVIRONMENTS: CHAUTAUQUA COUNTY REGION: NEW YORK STATE
GORDON C. BAIRD and GARY G. LASH
Department of Geosciences
State University of New York College at Fredonia
Fredonia, New York 14063
INTRODUCTION
The history of the study of the Paleozoic stratigraphic divisions in New York State spans, at least, two centuries, and it records the early development of important concepts centrally germane to the study of sedimentary basins worldwide (see Tesmer, 1989). The works of James Hall, John Clarke, Henry S. Williams, Joseph Barrell, and George Chadwick are well known to most sedimentary workers, as are those of numerous subsequent workers. In particular, the sedimentary sequences of the Allegheny Plateau Region ("Southern Tier" region) served as important sources of information for refinement of the facies concept and for the widespread recognition of the westwardly prograding Catskill Delta Complex which is the primary Paleozoic story recorded in Southern Tier bedrock deposits (see Chadwick, 1924, 1933; Cooper, et al., 1942; Caster, 1934; Woodrow, 1985).
The first significant geologic work relating to the Chautauqua County region was presented in James Hall's (1843) Survey of the Fourth Geologic District. Subsequent stratigraphic studies in this area include Clarke (1903), Chadwick (1923, 1924), Caster (1934), Pepper and de Witt (1950, 1951) and de Witt and Colton (1953). In northwest Pennsylvania, significant synthetic contributions include I.C. White (1881), Butts (1906-1908), Chadwick (1925), Caster (1934), Pepper et al. (1954). In Ohio, deposits equivalent to parts of the New York and Pennsylvania Upper Devonian section (Chagrin Shale) have been the subject of recent paleoenvironmental studies (see Weidner and Feldmann, 1983; Schwimmer and Feldmann, 1990). The present authors particularly build from the comprehensive work of Tesmer (1963) and the subsequent work of Murphy (1973) and Burrier (1977).
Both prior- and ongoing studies of the present authors are directed to the Canadaway-Chadakoin succession exposed on the Lake Erie lowland plain and adjacent escarpment. One of us (Baird) is currently tracing Chadakoin strata from Ohio northeastward along the escarpment to the vicinity of Fredonia, and he is also examining eastward (upslope) facies changes associated with the base of the Dunkirk Shale Member. Lash is currently working on the origins of interbedded siltstone-shale deposits and massive siltstone units (Laona and Shumla members) within the Canadaway Formation.

SatA: DEVONIAN STRATA AND PALEOENVIRONMENTS: CHAUTAUQUA COUNTY REGION: NEW YORK STATE

Cross Canadaway Creek. Gowanda Shale exposed in vicinity of bridge.

Several levels of river terraces
Several levels of river terraces are exposed on each side of bus at this point associated with earlier and higher stages of Lake Erie.

Cross Canadaway Creek bridge.
Good exposures of the upper part of the Gowanda Shale by bridge are continuous up to falls at Laona.

Stream terraces can be seen on the right side of the bus.
An abandoned oxbow lake can be observed 8 meters (25ft.) above the present level of the creek.

STOP 1. Laona Siltstone Member
Laona Siltstone over Gowanda Shale at waterfall 200 feet southwest of car park at bridge (Overlook Stop Only; we will be able to sample from this division at STOP 4). Note the sharp contrast between the conspicuously banded ("zebra" facies) of the Gowanda and the massive nature of the overlying Laona. The Laona and the higher Shumla siltstone are believed to be gravity-flow units which record downslope movement of silt or fine sand into the anoxic to minimally dysoxic lower slope-basin setting recorded by the Gowanda-Westfield-Northeast shale members.

Pass Al-Tech Corp. factory (to right).
OHM 2015: Became AlTech Specialty Steel State Superfund Site Number 907022 after Al-Tech went bankrupt in 1999.

STOP 2: Hanover Shale-Dunkirk Shale Contact At Point Gratiot
Point Gratiot is the type section for the Dunkirk Shale Member. Along the northeast side of the point the lower part of the Dunkirk is visible as is the uppermost 1 to 2 meters of the underlying Hanover Shale Member (Fig. 4A). The bioturbated grey Hanover contrasts strongly with the laminated brownish black beds of the Dunkirk. Pyritic burrow tubes are conspicuous in the uppermost Hanover and in the thin, 13.5 cm (4.5 in.), recurrent Dunkirk grey mudstone interval above the basal 15-17 cm (6.0-6.5 in.)-thick basal Dunkirk black bed, but no body fossils occur in the grey lithology except for pyritic goniatite steinkerns and wood debris; this grey sequence is classic for slowly deposited dysoxic facies (Rhoads and Morse, 1971; Byers, 1977).
The Dunkirk Shale is non-bioturbated at most levels but there is some evidence of internal burrowing as can be seen in the basal black bench. Body fossils in the Dunkirk are usually uncommon; the linguloid brachiopod Barroisella camhbelli occurs at some levels and both wood debris and fish fragments ave been found. The top of the basal black bench is particularly good for carbonized logs and fish debris (Fig. 4A); when viewing is optimal, a thirty foot-long tree trunk is visible on the surface. In the spring of 1986 one of us (Baird) and several S.U.C. Fredonia geology students recovered a partial skeleton of the giant arthrodire Dunkleosteus from this bed.
Although a bioturbated, conformable contact between Hanover and Dunkirk can be seen below the basal Dunkirk black bed which dips southward below the water at this section, the top of the 13.5 cm Dunkirk grey mudstone bed marks a submarine erosion surface which is "roofed" by black Dunkirk deposits; this contact is marked by abundant detrital pyrite in the form of reworked burrow tube fragments, nodules, and occasional goniatite steinkerns derived from the underlying grey mudstone interval which is conspicuously rich in pyritic tubes and nodules (Baird and Brett, 1986). Additional reworked components include fish bones, conodonts, and carbonized wood fragments. The abundance of wood and conodonts in the basal few centimeters of the overlying black shale suggests that this interval is unusually condensed, recording the descent of numerous logs from the water surface over a long period of time. This wood-rich unit also records bioturbation, which, at this section, was sufficient to flux the broken pyritic tubes into random orientations. Bottom erosion is believed to be due to sediment starvation on the seafloor during relative sea-level rise. Scouring of the substrate may have been accomplished by rare deep storm waves, bottom currents in the basin, or internal waves impinging a regionally sloped substrate (Baird and Brett, 1986; Baird et. al., 1988). Exhumed and concentrated detrital pyrite was preserved (not oxidized) in the anoxic to minimally dysoxic Dunkirk bottom setting.
In the early 1980s George McGhee and Edward Olsen sampled this section for the occurrence of iridium, a trace element believed by some to mark catastrophic extraterrestrial collision events in the rock record (see Alvarez et al., (1980). The Late Devonian Frasnian-Famennian (F-F) extinction event, one of five greatest Phanerozoic extinctions, was, until recently, believed to be coincident with the base of the Dunkirk. This event is similarly thought by some to be the possible record of an impact (Goodfellow, et al., 1988). However, no Iridium-rich horizon was found (McGhee,1982, 1988). Recent bistratigraphic work indicates that the F-F boundary is somewhere within the upper Hanover (Klapper, Kirchgasser pers. comm.) at a level which has not been precisely identified.
Note the "bedded" till above the Dunkirk and the striated bedrock contact below this "till."

Cross Canadaway Creek.

County Fly Ash Dump to the left (see Field Trip G, this volume).

Bridge over Little Canadaway Creek.

Entrance to Lake Erie State Park

Bridge over Slippery Rock Creek.
Exposures include the South Wales Member at the lake shore level and Gowanda Member at the bridge and upstream.

Bridge over Corell Creek.
Exposures are in the Gowanda Shale Member. The Corell's Point pyrite-goniatite bed is exposed approximately 120 feet upstream from the bridge.

STOP 3: Corell's Point Pyrite-Goniatite Bed In Gowanda Member
The Corell's Point Pyrite-Goniatite Bed, encompassing two regionally mappable levels of calcareous septarian concretions, is present at several creek localities in this county but this shore exposure is the best place to examine fossils and sedimentary structures (Fig. 4 B,C). At least two, laterally discontinuous beds rich in pyrite nodules and locally abundant pyritized cephalopod steinkerns can be traced within the lower septarian concretion zone along the shore and around the small headland. Goniatites include Cheiloceras amblflobum, Tornoceras concentricum, and Aulatornoceras bicostatum (Fig. 4C ; these belong to the zone of Cheiloceras (II) in the Famennian (see House, 1966; Kirchgasser, 1974). Orthoconic cephalopods are also common; these are commonly encrusted by a reptate auloporid coral. Slightly-curved conical shells less than one inch in length may be bactritid cephalopods or coleolid tubes. Bivalves, including Lunulicardium eriense, Praecardium multicostatum and Loxopteria corrugata occur with the cephalopods but these are usually preserved as non-pyritic composite molds often with a faint organic patina which may be a remnant of the periostracum layer. Driftwood, usually partly carbonized and partly permineralized by pyrite, occurs with the other fossils. Spectacular large Zoophycos spreiten in the Corell's Point Bed indicate that this trace had become important in offshore, dysoxic facies by the Famennian.
Babcock (1982), believed that the fauna of this bed was selectively preserved by turbiditic smothering events; some beds in this unit have shallow sole marks and display lamination similar to those in flaggy siltstone beds elsewhere in the Canadaway Formation. However, evidence of periods of reduced sediment influx is shown by intense bioturbation at some levels and by the tendency for auloporid corals to not only colonize partly-buried cephalopods but to extend colonial growth onto the adjacent seafloor. The history of this unit is complex and the presence of so many fossils at this level is suggestive of an episode of increased bottom oxygenation and reduced average turbidity.
The Corell's Point Bed is well exposed in Corell's Creek, Slippery Rock Creek near Brocton, Little Canadaway Creek near Lamberton, Canadaway Creek upstream from Route 20, and Walnut Creek at Forestville (House, 1966, 1968).
Examine the Gowanda-strata both below and above the Corell's Point Bed; notice the numerous brown-black shale beds which alternate with grey-green mudstone to produce the conspicuous striped banding along the shore (Fig. 4 B). This basinal "zebra" facies will be discussed in greater detail at STOP 4.

To the left (south) observe the elongate glacial landforms
To the left (south) observe the elongate glacial landforms which characterize this specific part of the lake plain. These deposits may represent reworked sand from older sand deposits of higher lake stages.

Bridge over unnamed creek south of golf club.
Exposures of Gowanda Shale include a 4.5 m (15ft.) waterfall at the lake and a conspicuous fossil wood concentration in a siltstone bed between the falls and Route 5.

STOP 4: Gowanda, Laona, And Westfield Members
Bridge over Bournes Creek. Park on shoulder and enter property on left (south) of Route 5.
This outcrop on Bournes Creek affords an opportunity to examine the Laona Siltstone over the Gowanda Shale and to sample the lower part of the still-higher Westfield Shale upstream from the waterfall. The Laona is expressed here as three massive, but relatively thin, siltstone beds which are separated by intervals of interbedded black and green shale ("zebra" facies). It is much more poorly developed here than at STOP 1 or in creeks between here and Barcelona (see road log below); apparently the Laona gravity-flow event involved channelization of the mobile silt such that this unit develops the thick, massive character only locally. Here it appears to be represented by three discrete flow events which must have occurred at separate times.
We will hike upstream to examine the lower Westfield section which is characterized by good development of the finely interbedded black and green-grey shale deposits ("zebra" facies) that are characteristic of much of the Canadaway succession (Figs. 6, 7). The black shale bands, typically less than one inch-thick, are usually laminated and they can be quite silty; some appear to grade laterally into siltstone beds, commonly containing wood debris. Grey mudstone beds sometimes pinch out laterally allowing black beds to merge. The grey mudstone deposits are fine grained and minimally bioturbated such that they appear structureless on a fresh break surface. The grey beds appear to be composed of turbiditic mud; there appears to be a spectral gradient from the grey mudstone layers through silty mudstone beds with incipient sole mark development to cross-laminated siltstone beds with good sole marks; at an initial glance, this would appear to be reasonable suite of bed-types that one might expect to see in an ancient prodelta slope environment where turbiditic silt was scarce with respect to mud.
However, complex internal cross-lamination of many siltstone beds suggests that processes other than turbidity currents may have produced them and that some beds may record multiple depositional events (see Stanley, 1987). Moreover, it appears that, at least, some of the thin black shale beds do not simply record stagnant anoxia and slow accumulation of organic-rich mud. Beneath many, if not most, thin black shales beds is a millimeter-thick zone of pyritic microspheres and partial microspheres which appear to have formed in situ within the uppermost, water-rich grey mud layer (Figs. 6, 7). Most of these are partial spheres with brilliant curved exteriors and flat tops marked by dull polyframboidal granular surfaces (Fig. 7). Some bear crenulated shiny exteriors reflecting compressive burial affects following formation of the pyrite.
These sand-size microspheres apparently record early diagenetic, bacterially-mediated pyrite formation within spherical spaces. We suspect that surface-ward migration of CO2 or methane may have produced bubbles which became trapped under the black mud layers or under bacterial mats associated with the black muds (Fig. 7). Sulfidic activity resulted in the partial-to-complete filling of the bubbles leaving the partially filled ones as useful geopetal indicators. Within the basal few millimeters of many black shale beds, the microspheres are again visible. However, partial microspheres are randomly reoriented, indicating that they have been disturbed after formation. Evidently microbioturbation during black mud deposition served to reorient the pyrite in some instances. In other black shales, the microspheres are concentrated in lag concentrations; this suggests that these black shale layers may have been deposited under the influence of tractional currents. Cuomo and Bartholemew (1987) and Cuomo and Rhoads (1987), have observed that both modern and ancient black muds are extensively pelletized by bottom organisms. If this is true, then the pelletized black mud may have been easy to mobilize through current action because it would have been like "Sand" or "silt". It is then possible that some of the thin black bands in the Canadaway Formation may be analogous to some of the tractional siltstone beds to which they sometimes laterally intergrade. Study of these complex and somewhat enigmatic deposits remains an on-going project.
In-situ microspheres are abundant beneath some of the black bands at this stop. Reoriented and hydraulically concentrated microspheres are locally common along the soles of siltstone beds where they have collected into scoured depressions, (corresponding to "positive" flutes, grooves, and excavated burrows) along such surfaces.

Unnamed creek to right (north).
Thick Laona section is present downstream from road.

Pass Barcelona Harbor complex.
Excellent shore exposures into the Gowanda Shale are developed north of dock area. This is a particularly clean section for observing "zebra" facies. Stone lighthouse was first to be illuminated by natural gas in the U.S.A.

Crossing Glacial Lake Whittlesey beach berm.

Cross Little Chautauqua Creek Gorge.

STOP 5: Northeast Shale Along Chautauqua Creek
At this brief stop we will examine a cutbank section and associated loose siltstone slabs which are typical of the Northeast Member. The Northeast is a typically "flaggy" sequence of thin grey siltstone beds interbedded with silty grey mudstone. Some siltstone layers appear to be turbidites which lack the basal graded division of the typical Bouma-sequence. Many beds display good sole marks with groove- and tool-marks. Networks of the trace fossil Planolites are common, and a trace resembling Zoophycos occurs more rarely. Some sole marks show hydraulic concentrations of exhumed and transported pyritic microspheres ; and partial microspheres in groove- and flute-casts; these were current-scoured depressions into which the coarser and heavier pyrite material selectively accumulated as currents waned. Cone-in-cone concretions occur at several levels within the Northeast Shale (Woodland, 1964; Gilman and Metzger, 1967); fragments of such concretions are occasionally observed in creek rubble at this stop. In-situ shelled fossils are rare to absent here as at many other sections of the lower Northeast Member. This facies records a dysoxic prodelta setting below the reach of most storm waves.

Start to cross lip of prominent lake escarpment
Start to cross lip of prominent lake escarpment marking edge of Allegheny uplands.

Group of buildings is hamlet of Summerdale.

STOP 6: Foerstia (Protosalvinia) Zone Within Ellicott Shale Member
Exposures of the Chadakoin Formation on Chautauqua Creek are the most complete in New York; the lower division (Dexterville Siltstone Member) is entirely exposed, and approximately 75 to 80 percent of the overlying Ellicott Shale Member can be observed on this creek and along its upper tributaries (Fig. 8). Recent discovery of about 38 meters (120ft.) of additional measureable Ellicott in a side tributary bordering Lyons Road allows us to observe a major siltstone division yielding the distinctive large rhynchonellid brachiopod Paurorhyncha newberryi (Figs. 8, 9): which has not been recorded prior to now within the county (Tesmer, 1963). In addition, discovery of the important algal taxon Foerstia (Protosalvinia) in the section at this stop (see text) allows us to establish equivalency of this outcrop with key parts of the Ohio, Antrim, New Albany, and Chattanooga black shales between New York and Oklahoma.
According to correlations and measurements of Tesmer (1963), and Burrier (1977), the Lyons Road section is within the Ellicott Shale approximately 33 meters (105 ft.) above the Dexterville Member. Mapping by Baird shows that the Dexterville-Ellicott boundary of Murphy (1973), corresponds to a level in Chautauqua County which is approximately 33 to 38 meters (105-125 ft.) above that of Burrier (see text). The Lyons Road section correlates to Murphy's Dexterville-Ellicott lithologic transition and the zone of abundant Foerstia that are characteristically associated with it; the boundary between Murphy's two members is approximately at the 1400 foot-elevation (Fig. 8, 9) which is below the old road shoulder (parking area for group) adjacent to the defunct bridge. This level also corresponds to an upward transition from siltstone-dominated "distal platform" Ellicott facies of Burrier (1977), to his mudstone-rich "prodelta" deposits at the upper end of his measured section. We will cross the mowed field area and collect from shell-rich, silty deposits near the boundary between the siltstone-dominated and upstream shale-dominated intervals.
Downstream from the bridge vicinity is siltstone-dominated, fossiliferous delta platform ("Chemung") facies of the Late Devonian (Rickard, 1975). The most conspicuous features are lenticular siltstone and fine sandstone beds interspersed with grey mudstone layers and coquinitic shell accumulations. Unlike the thinner and more continuously even-bedded slope and basin siltstone beds in the Canadaway Formation, these layers pinch and swell and there is abundant evidence of erosional truncation of older beds by younger ones. Storm layers dominate the section; tempestites, pararipples, occasional thick siltstone beds with hummocky cross-stratification, and gutter casts are all evidence for the impingement of storm waves on the substrate. Good tempestites display a weakly graded concentration of reworked shells, overlain by laminated siltstone with low inclination cross-stratification displaying internal bedding discordances (see Aigner, 1985). Gutter casts are erosional runnels, usually less than a meter in length which often have interiors similar to tempestites; siltstone- and shell-filled gutters are the result of scour- and filling-processes involving both oscillatory and unidirectional currents during storms (Aigner, 1985). These runnels are presently casted with siltstone and coquinites and they display "tool marks" produced by the bouncing and rolling of shells, wood, and other debris during the storms. Sole marks under many siltstone beds show disarticulated brachiopod shells visible as concavities on the sole surface; this is the result of mud "sheltering" beneath the stationary shell during the storm which is subsequently buried by silt. Later differential weathering removes the sheltered mudstone leaving the shell as a negative feature on the siltstone surface. Chadakoin storm beds decrease in size and complexity downslope into Pennsylvania and Ohio along a depth-controlled proximity gradient (see Aigner, 1985); this gradient can be better assessed through refined stratigraphic mapping within this formation.
Not only are the thick proximal storm beds represented in this section but thin, mud-dominated layers produced by smaller storms are common, particularly upstream in the shaley Ellicott interval. These distal tempestites record the transport and settle-out of mud which often smothered bottom organism as currents dissipated (Brett, et al., 1986). Excellent examples of articulated delicate fossils, including crinoids, echinoids, and glass sponges, found at the Lyons Road section attest to numerous bottom-smothering events recorded in this outcrop.
Abundant fossils belonging to a few standard brachiopod and bivalve genera can be collected here. Brachiopods including the rhynchonellid Camarotoechia contracta, the spiriferid Cyrtospirifer nucalis, and a productid Productella speciosa are ubiquitous, as are the bivalves Mytilarca chemungencis and Leptodesma patens. In particular, notice the partially dissolved character of the brachiopod shells. Evidently, carbonate undersaturation in the near surface muds and/or oxidation of pyrite in these same muds caused many of these shells to undergo variable amounts of dissolution. Fossils to look for include hexactinellid sponges, articulated inadunate crinoids and undescribed archaeocidaroid echinoids. Small fossils include the fucoid algal structure Foerstia and abundant black, chitinous polychaete jaw elements called scolecodonts. The best Foerstia can be collected from shelly beds in the vicinity of- and downstream from the junction point of the north-trending, gently sloped path with Chautauqua Creek (Fig. 9). These resemble 0.5 to 1.0 mm diameter black "tar splatter" marks on bed surfaces which frequently are branched in a characteristic "Y" pattern. A few bedding surfaces are crowded with this important fossil.

Cattaraugus exposure on left side of road.

Ellicott Shale on right and left side of road for next half mile.
It is rich in sideritic lentils and characterized by some pyrite-rich mudstone beds, fossils are scarce.

Cross Prendergast Creek.
Ellicott Shale along creek below bridge. Foerstia bearing strata equivalent to the section at STOP 6 occur along this creek north of (downstream from) Route 17 above the Stedman-Sherman road crossing at an elevation of 1380-1390 feet.

STOP 7: Strata Of Uppermost Ellicott Member
Ellicott Shale on left and right side of road for next 0.25 mile. Stop vehicles at west (downhill) end of section.
This will be a brief stop to examine beds in the highest Chadikoin Formation. In the lower part of the cut and, particularly in the drainage ditch, one can observe brachiopod coquinites associated with storm (tempestite) beds. The characteristic upper Ellicott rhynchonellid brachiopod Paurorhyncha newberryi occurs at one or two levels in this roadcut. Of particular interest are shells stacked like dishes due to the oscillatory motion of storm-currents on the substrate (see Kidwell and Aigner, 1985; Kidwell, 1986). The elevation of the upper (eastern) end of this outcrop is approximately 10 to 15 meters (30-50 ft.) below the projected level of the Panama Conglomerate which can be seen on the hill immediately south of this area (Tesmer, 1963).

We are crossing the northern limit of the "Bass Islands" structural trend
We are crossing the northern limit of the "Bass Islands" structural trend of drillers. The base of the Panama Conglomerate is anomalously elevated to approximately 1740 feet in this immediate area. Note abundant evidence of drilling activity (blue pumps and tanks) in nearby fields.

STOP 8: Panama Conglomerate Member Of Cattaraugus Formation
The Panama Conglomerate, named by Carll (1880), for 21 meters (70ft.) of quartz-pebble conglomerate and quartz-dominated sandstone exposed at Panama, Chautauqua County, is a conspicuous lenticular unit at the base of the Cattaraugus Formation (see Tesmer, 1963, 1974). It is one of several conglomerate-rich units within the Cattaraugus Formation of Chautauqua and Cattaraugus counties. The Panama is correlative with the LeBoeuf Sandstone in Erie County, Pennsylvania and in western Chautauqua County.
The Panama Conglomerate Member is composed of cross-bedded, quartz pebble conglomerate, quartz-rich sandstone and sandstones with dilute (sand-supported) pebble concentrations. Conglomerates are composed mainly of quartz pebbles with minor components of jasper and metamorphic rock. Pebbles are usually less than one inch in diameter, well rounded, and often display a distinctly flattened discoidal to prolate shape. Rare fossils described from the Panama include Cyrtospirifer chemungensis, Camarotoechia contracta, Ptychopteria sao, as well as gastropods, (Tesmer, 1963; Miller 1974).
Miller {1974) interpreted the Panama to be a "beach" or "near beach" deposit with the main sediment source area to the southeast. One line of evidence he used was the tabular shape of many quartz pebbles in the Panama as opposed to the more ovoidal pebble shapes he observed in the "fluviatile" post-Devonian Knapp and Olean conglomerates (see also work of Sames, 1966); abrasive imbricate stacking and sliding of pebbles in a beach-foreshore environment was cited to explain the tabular pebble condition. In addition, the distinctly bipolar (NW-SE) paleocurrent pattern for measured cross-bedding sets within Panama (Miller, 1974) appears to reflect tidal current processes acting in a coastal setting. The occurrence of brachiopods and marine mollusks in the Panama is further evidence of marine influence in this deposit.
A major question that geologists confront when examining deposits such as these is the problem of transporting and accumulating the vast numbers of quartz pebbles in this outcrop; clearly, a great volume of source terrain must have been denuded to produce it because vein quartz, chert nodules, and pegmatitic quartz make up only small volumes of normal lithosphere. This problem is partly obviated by the fact that the Panama Rocks outcrop is really more a thick lentil or channel feature which attenuates laterally to thin Panama facies dominated by sandstone (Tesmer, 1963; Miller, 1974). Hence, the volume of Panama quartz pebbles is really much less than this outcrop would initially suggest. Many of these pebbles may have been recycled from conglomerates in older Paleozoic units. Conglomerates are conspicuous features in the Ordovician Bald Eagle and Juniata divisions, the Silurian Oneida-Shawangunk and Tuscarora deposits, and in Middle through Upper Devonian proximal deltaic deposits of the Catskill Delta; Acadian overthrusting events probably exposed some or all of these easternmost sedimentary divisions to erosion, thus freeing up older pebbles for recycling. Post-Chadakoin sea level-fall and westward-northwestward advance of the paleoshoreline in western New York and northwest Pennsylvania probably served to introduce large numbers of quartz pebbles into the Chautauqua County region.
Many questions remain unanswered concerning these conglomerate units and the non-conglomeratic facies in between them. There are very few places where basal Cattaraugus (Venango) coarse facies can actually be seen in place rather than as slump blocks in creek beds or on wooded hillsides; it is essential to observe upper and lower contacts of units such as this to establish any sense of context for these units as geological events.
For those particularly interested in landscape and groundwater processes Panama Rocks offers a superb view of slope creep in action as well as weathering processes along joint systems developed in this deposit. The numerous "Dens" and "Alleys" between blocks also provide opportunity to examine the important role of "root pry" in forcing blocks apart. This park is one of several such tourist areas developed in conglomerate-rich deposits in this region.

Cross Prendergast Creek and continue over Kent ground moraine
Cross Prendergast Creek and continue over Kent ground moraine to vicinity of Chautauqua Lake.

Pleistocene and Recent alluvial sand and silt.
For the next several miles we will traverse over Pleistocene and Recent alluvial sand and silt.

Ascend Lake Warren beach berm.
Rt. 20 follows the top of this beach ridge for the next 8 miles. Numerous vineyards and orchards are developed on the sandy soil, as are numerous sand and gravel pits.

Cross Little Canadaway Creek.
Resistant siltstone beds within Gowanda Shale hold up waterfall 100 feet downstream from road.

Cross Canadaway Creek.
Monument (inscribed boulder) to left marks position of the first successful gas well which was drilled in 1825).

SatB: GEOLOGY AND OIL AND GAS EXPLORATION IN WESTERN NEW YORK
Jerold C. Bastedo (Ecology and Environment, Inc.)
Arthur M. Van.Tyne (Van Tine_ Consulting)
HISTORY OF OIL AND GAS DRILLING IN WESTERN NEW YORK ·.
SEEPS
Long before any drilling took place, local Indians had found natural oil and gas seeps at several places in western New York. The first recorded observation by white men of such an occurrence was in 1627. In a letter written in that year a Franciscan priest described his visit to the Cuba oil spring in Allegany County. He was taken there by a band of Indians who had used the oil at various times for medicinal, fuel and ceremonial purposes.
In 1669 Indians took the French explorer LaSalle and his party to a natural gas seep which they knew of in western Ontario County. While there, they lighted the gas and watched it burn. The event was recorded in a diary by one of the party and this account was later published.
FIRST WELLS
Possibly the first gas well drilled anywhere was located in the bed of Canadaway Creek where it flows through Fredonia. In 1821, William A. Hart, drilled a hole into the shale there to a depth of 70 feet and obtained a flow of gas. He piped and sold the gas to various places of business in the Village and it was also used to light street lamps.
According to Herrick (1949) the Hart well was still producing gas in 1858. From 1821 to 1858 others produced gas for commercial use, with varying success, from gas seeps in the Fredonia area. In 1858, searching for an additional supply of gas, Preston Barmore and Elias Forbes made a location for a new gas well. This was near a gas seep in Canadaway Creek about one mile north of the Hart well. The new well consisted of a dug cavity about 30 feet deep in the bottom of which two holes were drilled to depths of 100 and 150 feet. The holes found gas and the well was hooked up to supply gas to the Village.
In August of 1859 Edwin L. Drake made his great oil discovery near Titusville, Pennsylvania. That 69.5 foot hole showed that oil was reservoired in rocks and could be recovered from rock in greater quantity than from a seep by drilling a well into it. After the Drake discovery men began to drill all over western Pennsylvania and southwestern New York looking for oil.
No road log available at time of publication.

SatC: SEQUENCE STRATIGRAPHY OF THE TYPE NIAGARAN SERIES (SILURIAN) OF WESTERN NEW YORK AND ONTARIO
Carlton E. Brett, William M. Goodman And Steven T. LoDuca
Department of Geological Sciences
University of Rochester
Rochester, New York 14627
INTRODUCTION
Recent advances in sequence stratigraphy resulting from seismic profiling of continental shelf sedimentary prisms (Vail et al., 1977; Wilgus et al., 1988), combined with a renewed interest in cyclicity and periodicity in the sedimentary record (see, for example, Bayer and Seilacher, 1985; Einsele, 1985; Fischer et al., 1985; House, 1985) have had a revolutionary impact on the field of stratigraphy. Subdivision of sedimentary prisms into unconformity-bound, genetic stratal packages, or sequences, (sensu Vail et al., 1977; Fig. 1) has permitted seismic stratigraphers to make rather detailed intercontinental correlations and has provided a new genetic model of stratigraphic dynamics on continental shelves (see, for example, Van Wagoner et al., 1988; Posamentier et al., 1988a, b; Sarg, 1988; Galloway, 1989). If depositional sequences are produced, at least in part, by eustatic sea level fluctuations, then the principles of sequence stratigraphy should be equally applicable to epicontinental sea and foreland basin strata which appear to be highly influenced by high frequency, low magnitude sea-level oscillations (see, for example, Goodwin and Anderson, 1985; Busch and Rollins, 1984). However, to date, relatively few studies have attempted to discern unconformity-bound sequences in settings other than passive continental margins (notable exceptions include Nummedal and Swift, 1988; Cross, 1988). In order to test the applicability of sequence concepts to epicontinental strata, field geologists must begin to apply the model at an outcrop scale to a broad array of sedimentary environments. Only in this way can the generality of the sequence model be tested and peculiarities of continental interior and foreland basin sequences be distinguished from those characteristics specific to continental shelf deposition.

SatC: SEQUENCE STRATIGRAPHY OF THE TYPE NIAGARAN SERIES (SILURIAN) OF WESTERN NEW YORK AND ONTARIO

Note road cuts in cherty Onondaga Limestone (Middle Devonian).
This is the old Vogelsanger Quarry.

Cuts on left at underpass are in Upper Silurian Camillus Shale (and gypsum).

Bridge over Tonawanda Creek, enter Niagara County.

Type section of lower Gasport Fm. grainstone is cut on this road.

Small cut in red Grimsby Sandstone.

Note sewage treatment plant on left.

STOP 1A. Road Cut On W. Jackson Street Below Somerset Railroad Viaduct
(Queenston Shale- Medina Group).
This excellent and relatively new outcrop has been described previously in considerable detail (see Friedman, 1982; Duke et al., 1987). It provides an outstanding exposure of the basal Silurian Cherokee Unconformity and a good opportunity to study the lower units of the Medina Group as well as the uppermost beds of the Queenston Shale.
About 6 m (20') of upper red mudstones and siltstones of the Queenston Formation (Upper Ordovician, Ashgillian) are exposed at this locality. The Queenston has been interpreted as either very shallow marginal marine or non-marine red beds. The Cherokee unconformity in this area is the basal surface of Whirlpool Sandstone which is nearly planar. It is also a megasequence boundary separating the early or Creek phase of Sloss' Tippecanoe "megasequence" from the later Tutelo phase (see Dennison, 1989).
The Medina Group (Sequence I of the Silurian System), consists of an Early Silurian (early Llandovery, Al-B), siliciclastic wedge derived from tectonic source areas to the southeast (Figs. 1, 2). The lowest Silurian unit, white Whirlpool sandstone is about 3.5 m (11.5') thick at this location. Basal beds of the Whirlpool Sandstone are quartz arenites with northwest dipping cross strata which have been interpreted recently as nonmarine, braided stream deposits (Middleton et al., 1987). Large-scale channel-like structures occur in, or at least at the top of, these sands. Shale drapes within such channels at Lockport have yielded marine acritarchs (M. Miller, unpublished data) indicating that the channels were backfilled by very shallow marine sands and minor muds during a rise of sea level. Hence the irregular channeled surface that separates lower Whirlpool braided fluvial facies from upper Whirlpool hummocky cross-stratified, sparsely fossiliferous beds is a transgressive surface. The Whirlpool Sandstone thus is interpreted to contain both a lowstand (or shelf margin) systems tract and a transgressive deposit. A thin bed containing phosphatic pebbles and fossil grains occurs the Whirlpool-Power Glen contact. This phosphatic pebble bed may mark a marine flooding surface, or surface of maximum starvation associated with relatively increased rates of sea level rise. This surface marks the change from shallow shelf sands of the upper Whirlpool into deeper shelf muds and storm sands of the Power Glen Formation, herein interpreted as relative highstand deposits (subsequence IA). The Power Glen exhibits two small scale parasequences.
This outcrop is one of the easternmost exposures of the Power Glen Shale. At this locality the Power Glen Shale comprises of about 5 m (16') of greenish gray shale with thin tempestitic siltstone and sandstone beds. The basal meter-thick transitional zone consists of thin (2-10 cm) muddy sandstones with interbedded sandy shales. Sandstones in the Power Glen Shale feature small-scale hummocky lamination and gutter casts suggestive of shallow, storm influenced shelf deposition. Small burrows (Planolites) are common, but body fossils are rare.
Greenish to reddish sandy shales and reddish sandstones occur near the top of the Power Glen suggesting a minor upward shallowing trend. However, the top of the unit (as defined herein) is sharply demarcated at the base of a massive white to pink mottled sublitharenitic sandstone about 2.5 meters (7.7') thick. This unnamed unit corresponds with lenticular sandstone beds ("Devil's Hole Sandstone" of Duke et al., 1987) seen at Niagara Gorge (Stop 6). The basal and upper beds of the sandstone contain lingulid brachiopods and probable Lingula burrows.
The white sandstone appears to record a relative sea-level drop during which sands were distributed widely into the basin. The unit has some characteristics in common with the upper member of the Whirlpool Sandstone and, by analogy, is considered to be a relative lowstand to transgressive deposit.
The unnamed sandstone, in turn, is overlain by about 2.0 meters of brick red shales and interbedded sandstones assignable to the lower Grimsby Formation. These beds are ferruginous and exceedingly rich in fragments of lingulids with rare nautiloids and bryozoans. Thin spastolithic (oolitic) hematite stringers occur near the top of the unnamed sandstone and probably reflect reworking of sediments in shallow marine environments during an interval of sediment starvation. Hence, these shell-rich ferruginous sediments represent a condensed interval at the base of the Grimsby highstand deposits.
The reddish marine shales near the base of the Grimsby Formation pass upward into red and white-mottled sandstones and thin sandy shales. These beds are exposed high in the cut and are not readily accessible. This upper interval will be seen to better advantage at Niagara Gorge (Stops 4, 5, 6). Return to vehicles and reverse direction turning left at West Jackson Street.

OPTIONAL STOP 1B: Cuts Along Somerset Railroad
Northeast Of Niagara Street Crossing, Lockport, NY (Upper Medina And Clinton Groups)
Cut banks along both sides of the railroad track provide an excellent exposures of the upper beds of the Medina and Lower Clinton groups (Fig. 9). Lowest exposed units are reddish and white, mottled sandstones and sandy shales of the upper Grimsby Formation. A prominent 2.2 meter thick, pale pinkish sandstone unit (Thorold-equivalent), the overlying 3.0 meters (9') of red to greenish silty shale (Cambria Member), and about 0.5 m of pale greenish to white sandstone and sandy shale, referred to as the Kodak Formation, complete the Medina Group. The Lower Clinton Group (Sequence II) rests unconformably on the Medina Group with the contact marked by a thin phosphatic, calcareous sandstone. Only 24 cm (17") of Neahga Shale (Fig. 9) overlie the unconformity, followed by 1.9 m of crinoidal grainstone belonging to the Hickory Corners Member of the Reynales Formation. These units and the underlying Medina strata are comparable to the section seen at Lockport Junction Road (Stop 2A), and are described in greater detail for that section. The upper contact of the Reynales Limestone (upper sequence II boundary) is well exposed along the top of the cut on the southeast side of the railroad tracks. Here, the uppermost bed of Reynales crinoidal packstone crops out from beneath the soil cover. The surface is an irregularly sculpted and bored hardground with black phosphatic staining and what appear to be phosphatized stromatolites. This is a local manifestation of the major Upper Clinton unconformity.
Southwest of the main railroad cut are small, partially overgrown exposures along the southeast side of the tracks. Here a thin remnant of the upper Clinton Group (sequence IV and parts of V) can be observed. In the ditch, southwest of the end of the main outcrop are exposed about 37 cm of dark gray shale rich in phosphatic nodules. The unit, which yielded an acritarch assemblage identical to that of the Williamson Shale of the Rochester area, lies between the top of Reynales unconformity and the basal phosphatic bed of the Rockway Dolostone. The pale buff-weathering Rockway Member (0.5 meters thick) and its contact with the overlying pinkish gray grainstones of the Irondequoit Formation are visible in the small outcrop. Rochester Shale is poorly exposed in slumped banks between this outcrop and the Niagara Street crossing. Well-preserved bryozoans, brachiopods, and even cystoid calyces are occasionally found in patches of weathered shale along the southwest side of the tracks.
Return to vehicles and reverse directions, returning to the junction of Niagara Street and West Jackson Street.

STOP 2A: Lockport Junction Road Cut (lower)
(Upper Medina And Lower Clinton Groups)
This newly widened (1986) cut along Lockport Junction Road exposes a similar section to that seen along the Somerset Railroad cut (optional stop 1B). However, this cut does not show the upper Clinton beds.
The lowest beds are exposed beneath and just north of the overpass of Lower Mountain Road over Route 93. The basal units seen here are red shales near the top of the Grimsby Formation. These shales are overlain by a 1.0 to 1.2 meter thick, blocky, pinkish gray sandstone that displays color mottling due to bioturbation. Swirly spreiten of the trace fossil Daedalus occur sporadically near the top of the sandstone ledge. Detailed regional correlation by Duke and Fawcett (1987) indicates that this unit is the equivalent of the Thorold Sandstone at the Niagara Gorge. The upper contact of the sandstone is marked by a thin red silty bed containing a "hash" of lingulid shell fragments.
The Thorold, in turn, is overlain by 1.7 to 1.8 m of dominantly red silty shale of the (Cambria Member) uppermost Medina Group. This shale bears distinctive fine, white mottling due to bioturbation. Although previously assigned to the Grimsby Formation, this is a distinctive, ostracode-bearing shaley unit that overlies the Thorold Sandstone and is traceable regionally at least as far east as the Rochester area. We informally identify this unit as the Cambria Shale Member of the Thorold Formation, using this section as the type locality.
The upper portion of the Cambria Member is pale purplish to greenish gray sandstone and sandy shale that was formerly termed Thorold Sandstone. In actuality, this is simply a leached sandy zone in the Cambria Shale. The Kodak Sandstone, observed at Stop 1B, and about 1 m of Cambria Shale, have been removed here at the sequence I/II unconformity. Sandstones contain small Skolithos burrows and intercalated green shale beds, especially the topmost layer, contain prolific leperditiid ostracodes. The greenish color extends down about 30 to 50 centimeters below the upper contact where sandstones are mottled pale purple and green. This discoloration is probably associated with the top unconformity and deposition of overlying reducing sediments (Duke et al., 1987). Here, as at the Lockport railroad cut, the top of the Medina Sandstone is an erosion surface overlain by a thin (3 to 5 centimeter) dark gray, phosphatic sandy limestone (Densmore Creek Bed) with prolific Hyattadina brachiopod valves. A thin laminated siltstone rests on the bed at the contact with the greenish gray Neahga Shale, which at this locality is about 1.0 meter thick--substantially thicker than at Lockport (STOP 1B).
At the base of the Hickory Corners Limestone (Reynales) is a thin (3 to 5 centimeter) pyritic, sandy limestone packed with black phosphatic pebbles and shell fragments (Budd Road phosphatic Bed). It is overlain by about 40 centimeters of alternating greenish gray shales and thin limestones capped by a 60 centimeter thick ledge of nodular crinoidal pack- and wackestone at the top of the roadcut. These beds contain a prolific fauna including corals, brachiopods (Hyattidina, Dalejina, Platystrophia) and pentameric crinoid stems belonging to a newly described inadunate. The upper surface at this locality is a glacially striated pavement and the post-Reynales erosion surface cannot be observed.

STOP 2B: Lockport Junction Roadcut (Upper)
(Upper Rochester, Decew, Gasport Formations)
This large roadcut displays the upper part of the Rochester Formation (about 5 meters), DeCew Dolostone (2.5 meters), and Gasport Limestone (over 7 meters); it was described in detail as Stop 1 of Brett's (1982) NYSGA Guidebook article. However, since that time the exposure has been freshly blasted to widen Route 93. A subsequence boundary occurs between the dolomitic calcisiltites and shales of the upper Rochester Shale and the overlying DeCew Dolostone. The latter is a buff-weathering, silty dolostone with thin layers of intraclasts and contorted bedding. The basal contact is sharp and locally channeled, but nearly conformable. The upper Rochester and DeCew are burrowed in some levels; body fossils are rare but this exposure has produced long columns of crinoids in the lower DeCew.
The sharp and undulatory upper contact of the DeCew Dolostone with the Gasport Formation forms the boundary between the Clinton and Lockport Groups, and is interpreted as a sequence bounding unconformity (between sequences V and VI). The surface represents an abrupt lowering of relative sea-level and beveling of older strata. The basal Gasport bed is a greenish gray brachiopod-rich, crinoidal grainstone conglomerate with dolostone clasts eroded from the DeCew. Missing at this contact is the newly recognized Glenmark Shale, a fossiliferous gray shale with litho- and biofacies resembling the Rochester Shale .
Only the lower (Gothic Hill) member of the Gasport is present here. At this locality and at cuts along adjacent Gothic Hill Road this unit is exceptionally thick (7-8 meters) and composed of well to poorly sorted pelmatozoan pack- and grainstones. This facies is interpreted as a high energy crinoidal bank. Brachiopods are common in an argillaceous, thin-bedded unit near the top of the unit. A small bioherm composed of algal and bryozoan boundstone (micrite) occurs within the Gothic Hill Member. The overlying units will be examined at the next stop.

Exposures of fossiliferous Rochester Shale along Thrall Road
Exposures of fossiliferous Rochester Shale along Thrall Road were described as Stop 2 in Brett (1982).

STOP 3: Pekin Hill (Route 429) Road Cut At Underpass
Beneath Upper Mountain Road. (Gasport-Goat Island Formations).
This classic exposure, described in detail by Crowley and Poore (1974), displays biohermal structures characteristic of the lower Lockport Group. Although the exposure is becoming overgrown, it has been restudied recently as part of our stratigraphic revision.
The lowest stratum, barely visible in the northernmost end of the outcrop (east side of road) is a crinoidal grainstone which marks the top of the Gothic Hill Member (seen at the last stop). The crinoidal grainstone is overlain on the east side of the road cut by approximately 4 to 5 meters of thin-bedded, bioturbated argillaceous dolostone which Brett et al. (in prep) refer to as the Pekin Member of the Gasport Formation. A small bioherm, "rooted" in the underlying Gothic Hill Member, protrudes upward into the sparsely fosssiliferous Pekin Member on the west side of the road cut.
Of particular importance is the sharp upper contact of the Pekin Member with pink, fine-grained crinoidal and cladoporid coral -bearing dolomitic grainstones of the basal (Niagara Falls Member) of the Goat Island Formation on the east side of the road. This contact can be traced to near the concrete wall for the Upper Mountain Road overpass. Here, it is seen to drop in elevation, apparently defining a channel-like feature that underlies stromatoporoid-rich biohermal dolomicrites. The latter appear to laterally replace the pink grainstone facies of the Goat Island.
On the west side of the road, the main mass of the bioherm described by Crowley and Poore (1974) can be seen. It is evidently a continuation of the biohermal mass seen near the bridge footing on the east side. This bioherm appears to occur above the sharp and distinctly irregular contact of the Goat Island Formation. Again, this contact is channelized into the dark, argillaceous dolostones of the underlying Pekin Member. Hence the so-called "Gasport bioherm" at this locality appears to be a biohermal mass within the lower Goat Island Formation.
The bioherm consists of dolomicrite containing very abundant, large stromatoporoid heads, many of which are reoriented or overturned and hence, are not preserved in situ. Near the center of the biohermal mass, the dolomicrite facies passes abruptly into pale pinkish gray fine- grained grainstone, closely resembling the non-biohermal basal Goat Island facies on the east side of the road. The pale gray "reefy" dolomicrite facies appears both north and south of the grainstone pocket which appears to have filled the center of the large channel-like feature cut into the top of the Pekin Member. Also note two or more sharply defined surfaces within the biohermal masses that may represent minor erosion surfaces. Overall, we interpret the bioherm here as a possible bank of algally (?) bound micrite and stromatoporoids (and a few tabulates) that lined a (storm surge?) channel cut into the muddy carbonates of the Pekin Member. The center of the channel was occupied by fine carbonate sand but was eventually "overrun" by the biohermal facies developing inward from the two channel margins. The channel itself was apparently oriented NW/SE, roughly perpendicular to regional facies strike. The erosion of the Pekin Member mudstones may have occurred during a relative sea-level lowstand that marks the boundary between Gasport and Goat Island depositional subsequences. (For a radically different interpretation of the stromatoporoid facies as a late successional stage of a Gasport bioherm, see Crowley, 1973, and Crowley and Poore, 1974).
The outcrop continues south of the Upper Mountain Road bridge. Here the upper portion of the stromatoporoid biohermal mass is abruptly overlain (contact now obscured) by thin-bedded, fine-grained, buff-weathering dolomicrite with bands of white chert nodules. We refer to this facies as the middle or Ancaster Member of the Goat Island Formation. Note a distinctive marker bed of silicified Whitfieldella brachiopods. The cherty facies records a general deepening trend in the upper Goat Island. It is somewhat comparable to the Pekin Member of the Gasport, but the latter is not cherty.

Niagara Air Force Base on
left.

STOP 4: Niagara Stone Quarry (Lockport Group)
This active quarry provides the most complete section of the Lockport Group in the Niagara region. Aspects of the jointing and hydrogeology of the Lockport at this locality are discussed in detail in the contribution by Tepper et al., this guidebook). We will briefly examine the overall stratigraphy focusing on the Goat Island Formation. The section extends from the top of the DeCew Dolostone and its unconformable contact with the overlying Lockport Group (sequence V/VI boundary) to beds near the base of the Guelph Formation at the quarry rim. The lower Gasport limestones-appear to fall in the sagitta conodont zone making them late Wenlockian in age. Furthermore, recent graptolite discoveries indicate that the Wenlockian/Ludlovian boundary lies close to the Gasport/Goat Island contact (LoDuca and Brett, in press). Kleffner (1989) obtained siluricus zone conodonts from the upper Eramosa beds here.
The DeCew Dolostone is observable in the deepest part (lowest lift) of the quarry where it exhibits a contorted upper surface and internal hummocky cross-stratification. The sequence bounding unconformity between the DeCew and the Gasport Formation of the Lockport Group is marked by a thin, greenish (glauconitic) grainstone containing rip-up clasts of DeCew Dolostone up to 10 centimeters across. The lower or Gothic Hill Member of the Gasport is a massive, 5 meter thick interval of light pinkish gray, commonly orange weathering, crinoidal grainstone. The overlying Pekin Member is a 5 meter-thick interval of thin to medium-bedded, medium gray argillaceous dolostone . A bioherm extends up through the interval in the northwest corner of the deep pit.
The lower Goat Island (Niagara Falls Member) can be examined along the top of the ramp road leading to the lowest pit of the quarry, although the basal contact with the Pekin Member is obscure and inaccessible. The upper 1.5 meters of the Niagara Falls Member is a distinctive interval (Niagara Falls C unit) consisting of very dark gray, vuggy dolostone with distinct, white weathering stromatoporoids and corals. These and immediately underlying beds reflect a relative sea-level lowstand corresponding to the biohermal bed of Pekin cut. Beds overlying the Niagara Falls Member are assigned presently to the Ancaster and Vinemount Members of the Goat Island Formation. Both of these units have their type sections near Hamilton, Ontario.
The middle Goat Island interval is well developed in the walls above the second lift. The platform below is bulldozed off on a surface within the Ancaster Member. Thin flaggy beds of pale buff-weathering, fine-grained dolostone in the lower half meter of contain the chert nodules that characterize the Ancaster Member in its type area. However, the overlying interval is medium to thick-bedded, buff colored, medium-grained and generally noncherty dolostone. A distinctive layer of silicified and valves of Whitfieldella brachiopods occurs about 1.5 meters above the second lift. This layer may correlate with the Whitfieldella bed seen at the Pekin road cut (Stop 3).
Ancaster facies are interpreted to represent a similar offshore, low energy shelf environment. The abundance of chert in the Ancaster is unique among the Silurian units in the Niagara region; the cherts may reflect the availability of biogenic silica from the abundant sponges which occupied the seafloor at this time, although this is probably not a complete explanation.
The uppermost half meter of the Ancaster Member is marked by numerous vugs that appear to represent small corals and stromatoporoids. This bed is abruptly overlain by a layer of dark gray dolomitic shale that marks the base of a 3 m-thick bituminous argillaceous unit. Detailed outcrop and subsurface tracing of the unit indicates that it is coextensive with the Vinemount shale beds of the Hamilton, Ontario region. These argillaceous beds appear to grade laterally and vertically into Ancaster cherty dolostone beds and hence both are assigned member status in the Goat Island Formation. The Vinemount here comprises about 3 meters of dark gray, bituminous and argillaceous dolostone with some shale partings. Fossils are rare and poorly preserved, but include rhynchonellid and atrypid brachiopods, small rugose and favositid corals and the large nautiloid Dawsonoceras.
Together, the three members of the Goat Island Formation comprise an upward deepening (retrogradational) subsequence. It is marked at the base by an erosion surface between the Pekin Member of the Gasport Formation and the Niagara Falls Member of the Goat Island. The top of the Niagara Falls Member constitutes a marine flooding surface. Cherty beds of the basal Ancaster reflect relatively slow deposition during the early highstand.
The upper quarry walls above the Vinemount display the entirety of the Eramosa Formation (formerly called Oak Orchard Member; see Zenger, 1965). Recent work (Brett et.al., in press) indicates that "Oak Orchard" is an invalid term since the highest unit is exposed on Oak Orchard Creek is equivalent to the Vinemount beds. Furthermore, tracing of key units into Ontario indicates their correlation with the Eramosa and lower Guelph Formations in the type areas of Canada.
A number of informal units are recognizable within the Eramosa and are visible in the wall. Lowest is a 1.8 meter thick, massive, biostromal bed containing white gypsum filled vugs. This is succeeded by a rather nondescript, fine- grained facies 3.5 m which, in turn, is overlain by biostromal or thrombolitic dolomicrite. Notable are the two flaggy-weathering intervals at the top and base of this zone that may represent minor discontinuities. Toward the top of the quarry are 6 m Eramosa Formation, containing large, lenticular stromatolitic bioherms observable in the south wall .
Overlying units, at or near, the quarry rim are about 1.5 to 2.0 m of biostromal brownish gray dolostones with very abundant Favosites corals some of which are infilled by purple fluorite. The topmost bed in parts of the quarry is a light gray-weathering, stromatolitic (LLH) dolostone which forms a regional marker.
The Eramosa interval appears to represent an upward shallowing succession (subsequence) reflecting late highstand conditions.

STOP 5A. Robert Moses Access Road And Forebay
(Upper Lockport Group)
Higher units of the Lockport Group are visible along the fore bay and access road to the Robert Moses Power Plant, just west of Military Road and 0.9 miles north of Route 31. Here we will briefly examine, from a distance, exposures in the forebay canal of the upper Eramosa (new usage in New York) and lower Guelph Formations. Note the large algal bioherms which characterize the uppermost units of the Eramosa Formation in Niagara County (seen at Stop 4). The highest units in the forebay canal are more or less tabular stromatolitic dolostone which are, at present, assigned to the basal beds of the Guelph Formation (Fig. 16). Exposures in the small road cut at the underpass of the access road beneath the lanes of I-190 contain exceptionally large stromatolites. These strata represent a very distinctive marker horizon in the basal Guelph beds in western New York. The stromatolite heads are approximately 2 meters across but superimposed on these are small digitate upward growths of stromatolitic boundstone. The stromatolitic horizon is thought to be traceable at least to Hamilton where it comprises the basal transition bed between the Eramosa and Guelph.

STOP 5B: North End, Niagara Gorge
Between Lewiston-Queenston Bridge And Robert Moses Power Plant (Clinton Group)
Park vehicles near small building on right. Proceed on foot through railroad underpass (under Route- 104). At far end turn left, walk up slight embankment then down other side to exit lanes onto Robert Moses Parkway. Turn left and walk across exit lane and carefully cross two lanes of Rober Moses Parkway. At 55 mph sign step step over guard rail and down a slope bearing right (north) to cliffs along Niagara Gorge. (Note: permission should be obtained from Niagara Parking Commission for access to this stop.)
The Rochester Shale in this cliff exposure along the east face of Niagara Gorge was described in detail by Brett (1982). It provides an excellent section of the entire Clinton and Lower Lockport units. It also provides excellent fossil collecting in the Rochester Shale.
Proceed down to a small ditch in the gorge nearly opposite the Irondequoit-Rochester contact in the main cliff exposure. At its base, this gully exposes orange-weathered Thorold Sandstone, overlain by a thin (about 0.5 m) maroon and pale green sandy shale situated beneath the Neahga Shale. This is the last vestige of the Cambria Shale. To the south and west it has been lost to pre-Neahga erosion. A thin, Hyattidina- bearing, calcareous sandstone (Densmore Creek Bed equivalent) occurs at the base of the Neahga Shale. The latter is about 2 meters thick, dark gray, fissile gray shale. The overlying Reynales Limestone with a thin basal phosphate bed (Budd Road Bed) is nearly identical to that seen at Lockport Junction Roadcut (Stop 2). Note thick, nodular, coral-bearing packstone at the top.
Exposures in the main wall of the gorge show the basal contact of the overlying Rockway Dolostone. A 10-15 cm phosphatic, black shale resting on the Reynales represents a thin tongue of the Williamson Shale. This contact is sharp and represents a major unconformity at which most of the lower and middle Clinton units have been beveled (compare STOP 1B).
The overlying Rockway Member (of the Irondequoit Formation, Kilgour, 1963) is a buff-weathering, argillaceous dolostone with thin shales. The Rockway shows prominent bands, ranging from a few centimeters to half meter thick, of argillaceous dolomite, which are interbedded with thin green shales. These two interbedded facies define a small scale cyclicity which can be traced on a regional basis. Rockway beds apparently record relatively sediment starved, off-shore marine lime and siliciclastic muds. Extensive dolomitization has obscured the fossil content of this unit. However, large brachiopods (Costistricklandia) are locally abundant, particularly in the middle thick bedded unit of the Rockway. Dendroid graptolites, rare favositid corals and nautiloids fossils are occasionally found. On the basis of conodont biostratigraphy, the Rockway belongs to the upper part of the amorphognathoides zone (latest Llandovery to earliest Wenlock Series).
It should be noted that the rock, here termed Rockway Member of the Irondequoit Formation, whose type section is in Canada (15 Mile Creek at Rockway, Ontario), is commonly referred to as the upper beds of "Reynales" limestone by Canadian geologists. However, the Sequence IV boundary unconformity, cuts out the true Reynales Limestone just west of the Niagara Gorge. Hence, the true Reynales is absent in Canada, except along the Niagara River.
A sharp contact separates the Rockway from the overlying massive, crinoidal grainstones of the upper (Model City) member of the Irondequoit. Clasts of fine-grained dolostone derived from the underlying Rockway occur in the basal thin bed of the Model City.
The upper member of the Irondequoit Formation (Model City Member of Brett et al., in press), consists of massive, pinkish-gray, crinoidal limestone and dolostone which rests with the sharp and slightly disconformable surface on the upper shaley, beds of the Rockway Member (Subsequence IVB). In places a thin phosphate or pyrite crusted surface delimits the upper surface of this 6 inch band. This pyritic crust probably marks a hardground. The Model City member shows a minor trend of upward deepening toward the top and a conformable, although abrupt, contact with the overlying Rochester Shale. Faunal density is interpreted as representing a shallow, highly agitated (near wave base) crinoidal shoal environment; brachiopod assemblages suggest a benthic assemblage-(BA) 3 paleobathymetry. Conodonts indicate an earliest Wenlockian age.
The Model City in turn, is interpreted as a transgressive systems tract of subsequence VA (Fig. 15). Its sharp upper contact with the Rochester Shale, which is locally glauconitic, is considered to be a surface of maximum starvation (marine flooding surface). In the cliff opposite the small ditch (which exposes the Thorold-Reynales) a small micritic (algal?) bryozoan bioherms protrude from the top of the Model City into the overlying Rochester Shale.
The overlying Rochester Shale, which is about 18 m thick, is a gray calcareous to dolomitic mudstone with numerous thin carbonates representing shell-rich and carbonate-silt storm deposits (Fig. 15). It can be examined by walking south along the base of the cliff toward the Robert Moses Power Plant. Though the Rochester initially appears homogeneous, it shows a distinct internal cyclicity which is traceable very widely. Most notable is the medial band of bryozoan-rich carbonates that occurs about 9 m above the base of the Rochester Shale. The sharp top of this unit has been used to demarcate the boundary between the Lewiston and Burliegh Hill Members of the Rochester Shale (Brett, 1983).
The Lewiston Member itself displays an alternation of fossiliferous limestones and calcareous shale intervals with nearly barren shale. Bryozoan rich beds occur up to about 10 feet above the base (Lewiston B unit). This fossiliferous unit is followed by a barren shale zone containing only thin calcisiltites (Lewiston C). This barren unit, in turn, gives way upward to bryozoan rich mudstones and finally, bryozoan pack- and grainstones (Lewiston D and E; Fig. 14). These facies alternations are interpreted as defining small scale cycles (parasequences).
The overlying Lewiston E limestone appears to be a weak signature of a relative sea-level fall and subsequent transgression. In short, a relative sea level drop followed by a rather rapid sea level rise is envisioned for this portion of the section (Fig. 2). Although no erosion or even sharp surfaces are seen at the base of the Lewiston E bed at Niagara Gorge, as this bed is traced westward onto the Algonquin Arch, it shows an increased sharpness to its base and, eventually, an erosion surface beneath the Lewiston E truncates most of the beds of the lower Lewiston. The upper surface of the Lewiston is sharp and locally glauconitic, and shows an abrupt change to the barren dark gray Burleigh Hill shales. This contact, again, is interpreted as a surface of relative sediment starvation, or marine flooding surface, associated with increased rates of sea level rise. The Burleigh Hill shales are largely barren of fossils and show relatively few interbeds, except in the upper third, where the unit becomes silty and contains some thin fossil stringers (Fig. 7). The member on the whole is considered to be an upward shallowing or regressive cycle (highstand deposit). As such, it can be interpreted as representing highstand conditions with minor progradation of carbonate silt toward the end of Rochester Shale deposition. The contact with the overlying DeCew Dolostone may locally appear sharp or gradational. A minor diastem is likely and subsequence boundary is placed at the bottom of the DeCew dolostone, but no major sequence bounding unconformity occurs at this surface.
The DeCew is an interesting 9 m thick, blocky dolostone which shows spectacular soft sediment deformation. The deformation may be interpreted as a response to single event, possibly a seismite associated with early pulses of tectonic activity during the onset of the Salinic Orogeny in eastern New York. Shaley beds of the DeCew are present locally along Niagara Gorge but have been removed in most areas seen on this trip.
The base of the Gasport crinoidal grainstone also seen at STOP 2B, is similar to the base of the Model City grainstone in that it contains rip-up clasts of dolomitic, argillaceous dolostone derived from the underlying, finer grained unit. To the west, this erosion surface removes the DeCew entirely in the vicinity of Hamilton, Ontario and further cuts out the upper beds of the Rochester Shale northwest of Hamilton. The lower Gasport Gothic Hill Member shows spectacular small scale trough and planar cross stratification. Some of this bedding appears to be bipolar, possibly indicating the influence of tidal currents. Like the similar Irondequoit grainstones, the lower Gasport grainstone is interpreted as an amalgamated crinoidal shoal deposit consisting of multiply reworked pelmatozoan sand and gravel. No Pekin Member is present here. Instead, a 2 meter thick vuggy, stromatoporoid-bearing dolostone (basal Niagara Falls Member A) of the Goat Island Formation rests directly on the Gothic Hill (lower Gasport) grainstone. Overlying beds, largely inaccessible, consist of bluff dolostone and tan cherty dolostones (Ancaster Member).

STOP 6: South Haul Road To Robert Moses Power Plant
Parking area for fisherman on left. Pull in and park. We will proceed on foot down the south haul access road for about 0.3 miles to the fishing area near the bottom of the gorge.
Please note: access to this section must be obtained from the Power Authority; hard hats are required and collecting is not permitted,
This outstanding outcrop, arguably the most complete Silurian section in New York State, provides an opportunity to summarize and review all of the points of the preceding trip.
The section begins with about 8 m of the upper Ordovician Queenston Shale. Its sharp contact with the overlying Whirlpool Sandstone is the Silurian sequence I boundary. The Whirlpool, here as at Lockport (Stop 1); is represented by channel facies which record a nonmarine to marine transition. Minor phosphatic material occurs at the upper contact (starvation surface, or marine flooding surface) with the Power Glen.
The Power Glen is both thicker (8 m) and shalier at this locality than the section seen at stop 1. It is entirely gray shale, lacking the upper reddish sandy zone seen at Lockport.
As at Lockport, the Power Glen is overlain by a 2 meter thick massive white quartzose sandstone (Devil' s Hole Member of Duke et al., in press), the base of subsequence IB of the Medina Group. Overlying (lower Grimsby) shales here are green and fossiliferous, in contrast to the red, ferruginous, lingulid shales seen at Lockport. The locality represents a more offshore section.
At the north end of Niagara Gorge a distinct, meter-thick phosphatic sandy dolostone, the Artpark Phosphate Bed, occurs in this position. Here, only minor phosphatic sandstone overlies the "Devil's Hole" Sandstone. These beds and the ferruginous zone at Lockport constitute a condensed section associated with rapid sea-level rise.
The main body of the Grimsby Formation (about 15 m thick) is red shale with thin sandstones. Three or four small-scale shallowing upward shale to sandstone cycles have been recognized by Duke et al. (1987) in this interval. This section is one of the most shale-rich exposures of the Grimsby in Niagara County. Sections both north and south of this locality contain more channel sandstones.
The upper beds of the Medina Group comprise about 2 meters of white, crossbedded Thorold Sandstone. The Thorold has a sharp erosive base which marks the base of the next Medina subsequence. Overlying Cambria Shale, seen at stops 2 and 5, is completely missing here. The sandy phosphatic Densmore Creek Bed rests sharply on the Thorold, marking the sequence I/II boundary.
The Neahga Shale is poorly exposed but is about the same thickness as at stop 5 on the north side of the power plant. The two phosphatic beds of the basal Reynales Limestone and the nodular capping bed are nearly the same as in the other sections seen in Niagara County. A prominent black phosphatic staining occurs on the upper surface of the Reynales Limestone (see near one of the protective cages on the outcrop). This stained surface is the sequence II/IV contact.
The Rockway/Model City (sequence IV/V boundary) is also well displayed. No bioherms occur here at the upper contact of the Irondequoit Limestone with the Rochester Shale, but a 30 centimeter thick shell bed marks the condensed zone. The lower Rochester Shale is partly obscured by a protective cage (toxic chemical seep?), but upper limestone beds of the Lewiston Member are well exposed. Overall the Lewiston Member is somewhat less fossiliferous and contains fewer limestone beds than at stop 5, just on the north side of the power plant. This loss of interbeds reflects the beginning of a major facies change into sparsely fossiliferous Rochester Shale southward along Niagara Gorge (see Brett, 1982).
The upper Rochester displays a sharp contact with the enterolithic DeCew Dolostone beds, herein interpreted as the basal unit of a partially eroded upper Clinton subsequence. The sequence V/VI boundary at the DeCew/Gasport contact is well exposed near the entrance to the "tunnel" beneath the Robert Moses Parkway at the top of the cut. Weathered surfaces of the Gothic Hill grainstones display probable bipolar cross-stratification. In contrast to the cut on the north side of the power plant (stop 5) some 2.5 meters of argillaceous upper Gasport (Pekin Member) strata are present here. These beds display a sharp undulatory contact with overlying vuggy dolostones of the Niagara Falls Member of the Goat Island Formation. The base of the Niagara Falls Member is a subsequence boundary which erosionally bevels the 2.5 meters of Pekin Member strata between the two sides of the power plant.
As a whole, the Gasport Formation comprises a complete subsequence. The basal crinoidal grainstones of the Gothic Hill Member represent transgressive systems tract deposits, the contact with the Pekin Member is a marine flooding surface and the Pekin muddy carbonates represent relative highstand deposits (Fig. 15). This subsequence is analogous to the Model City - lower Rochester Shale subsequence.
The dark, argillaceous dolostones of the upper Gasport Formation are sharply and erosionally overlain by basal medium-bedded dolostones of the Goat Island Formation (Fig. 16). This erosional contact is the same one observed at Pekin Roadcut (Stop 3). These dolostones, in turn, are overlain by massive, dolomitic, crinoidal grainstones appear at the type section of the Goat Island Formation at the brink of Niagara Falls. The south haul road section is a reference section for the lower portion of Goat Island Formation (Zenger, 1965). The unit is crinoidal and contains scattered Cladopora corals and stromatoporoids. Upper beds of the Niagara Falls Member display abundant vugs which appear to be solution cavities in a stromatoporoid-rich zone. This layer is locally highly biostromal, as noted at Niagara Stone quarry (STOP 4).
The Ancaster Member is poorly developed compared to that seen at Niagara Stone quarry (STOP 4), thin (-2.5 m) and only sparingly cherty. However, in the cliffs immediately north of the Robert Moses Power Plant, this member is developed in its typical thick cherty phase. There appears to be a complementary relationship, in terms of thickness, between the Niagara Falls Member and the overlying Ancaster Member; i.e. where the Niagara Falls Member is thick, the Ancaster is thin to nonexistent and vice versa. Argillaceous gray dolostones of the Vinemount Member form the uppermost unit on the access road.
The Goat Island Formation as a whole here appears to be a "twin cycle" to the Gasport. The lower or Niagara Falls grainstone member constitutes the transgressive portion; its sharp boundary with the overlying Ancaster Member is a surface of starvation, sometimes recorded in the relatively glauconitic cherty beds of the lower Ancaster (Fig. 16). Ancaster and Vinemount Members represent highstand deposits.

SatD: EURYPTERID BIOFACIES OF THE SILURIAN-DEVONIAN EVAPORITE SEQUENCE: NIAGARA PENINSULA, ONTARIO, CANADA AND NEW YORK
Samuel J. Ciurca, Jr.
Rochester, New York 14621
For the past 28 years, I have been studying eurypterids, their stratigraphic occurrence, distribution, and associated flora and fauna, particularly in northeastern United States and Ontario, Canada. In New York the best known eurypterid assemblages are: 1) the Eurypterus remipes Fauna of the Fiddlers Green Formation that includes the earliest discovery of an eurypterid on this planet (by Dr. Mitchell in 1818); 2) the younger Eurypterus lacustris Fauna of the Williamsville Formation of western New York and Ontario, Canada; and 3) the eurypterid fauna of the Shawangunk Formation southeastern New York.
The search for new eurypterid faunas and the study of their geographic distribution in the Siluro-Devonian rocks of the region is important for several reasons. Foremost is the fact that the eurypterid faunas are punctuated within the known stratigraphic sequences. New genera appear suddenly within the sequences, e.g. Waeringopterus Zone, Erieopterus Zone, etc. When an eurypterid species disappears from the record completely, it is easily understood and we often assume extinction. The sudden appearance (or ecological replacement) of a species by an unrelated forms, (such as the Silurian Eurypterus being replaced by Erieopterus in the Early Devonian, is much more difficult to decipher. Only continued search for intervening occurrences, stratigraphically and geographically, will provide the data needed to understand the evolution of the eurypterids and their assemblages.
A second factor of significance concerns the eurypterid assemblages. Generally, where eurypterids are found there is a conspicuous absence of other fossils, in number and especially in diversity. Hence, the stratigraphic sequence is often considered to be unfossiliferous. The evaporite-bearing Salina Group is notable of this designation. Precise correlation, regionally and inter-regionally is needed to achieve a more complete understanding of these unique invertebrates. See Figure 1 for a map showing areas having exposures of Late Silurian-Early Devonian strata.

SatD: EURYPTERID BIOFACIES OF THE SILURIAN-DEVONIAN EVAPORITE SEQUENCE: NIAGARA PENINSULA, ONTARIO, CANADA AND NEW YORK

STOP 1. Ridgemount (Campbell) Quarry
Camillus Shale or Oatka Shale forms the quarry floor. Above this is a thin representation of the Morganville Waterlime followed by massive beds of the Victor Dolostone. Several feet of Ellicott Creek Breccia are accessible on the northeast side of the quarry and from this many eurypterids have been obtained (Ciurca and Gartland, 1976). The higher strata, including the Williamsville Waterlime, are all visible in the quarry walls. The Devonian Bois Blanc Formation is particularly fossiliferous in this quarry.

STOP 2. Welland Canal Underpass Roadcut
SYRACUSE FORMATION (SALINA GROUP). A portion of the Syracuse Fm. is well exposed exhibiting gypsum beds, fine-grained dolostone replete with cavities formed by dissolution of evaporites. Crude algal mounds are present and the facies developed here is identical to that displayed in the type area in central New York.
Waeringopterus, characteristic of the lower or transitional beds of the Syracuse Fm., occurs here in the argillaceous dolostones.

STOP 3 Quarry At Byng
The Bertie Group is prominent in the lower portions of the quarry. Particularly important is the sequence above the Cobllekill Formation at this site. The Clanbrassil Formation makes its appearance beneath the unconformity at the base of the Bois Blanc Formation. In this quarry the Clanbrassil Fm. consists primarily of waterlimes, i.e. very fine-grained dolostones having conchoidal fractures. The only fossil obtained from the Clanbrassil Fm. at this locality is Erieopterus.

STOP 4. Cayuga Quarry
This large quarry complex contains an important section including the Williamsville Waterlime and the Clanbrassil Formation. Erieopterus seems to be more common in the Clanbrassil Fm. and in the quarries at Haggersville.

STOP 5. Abandoned Quarry
Type section Clanbrassil Formation. The Clanbrassil Formation occurs in the walls of an abandoned quarry at the Stone Crest Farm.

SatE: UPPER DEVONIAN TURBIDITES IN WESTERN NEW YORK: CHARACTERISTICS AND IMPLICATIONS FOR SUBMARINE FAN DEPOSITION MODELS
ROBERT JACOBI
Department of Geology; SUNY at Buffalo; 4240 Ridge Lea Rd; Buffalo, NY 14226
MICHAEL GUTMANN
URS Consultants; 570 Delaware; Buffalo, NY 14202
AL PIECHOCKI
SUZANNE O'CONNELLv Department of Earth and Environmental Sciences; Wesleyan University; Middletown, CT 06457
JILL SINGER
Department of Earth Sciences; State University College at Buffalo; 1300 Elmwood Ave.; Buffalo, NY 14222
CHARLES MITCHELL
Department of Geology; SUNY atBuffalo; 4240 Ridge Lea Rd; Buffalo, NY 14226
STEVE FRANK
DAVID SCHEUING
Lamont-Doherty Geological Observatory and Department of Geological Sciences; Columbia University; Palisades, NY 10964
STEVE HASIOTIS
PREFACE
The object of this field trip is to acquaint you with some of the characteristics of Upper Devonian turbidites in western New York* (WNY). We will examine three coarsening-upward clastic depositional cycles within the West Falls, Perrysburg and Java formations. The many gorges and ravines in WNY provide the control necessary to trace individual sandstone beds across the region, allowing us to characterize their interrelationships and their lateral variability in bedforms, texture, and thickness. From these and other data we believe the WNY turbidites in this part of the sequence represent lobe fringe and sand lobe deposition on a submarine fan. Continued study of these turbidites will help resolve problems encountered in both modern and ancient submarine fan research. Construction of a depositional model based on this research will entail 1) deposition and flow characteristics for individual non-channelized turbidity currents, 2) relationships, among various fan elements, and 3) fan vs. clastic ramp development. A more detailed discussion of the research rationale and results is presented in Jacobi et al. (in press)

SatE: UPPER DEVONIAN TURBIDITES IN WESTERN NEW YORK: CHARACTERISTICS AND IMPLICATIONS FOR SUBMARINE FAN DEPOSITION MODELS

Bridge crossing the South Branch of 18 Mile Creek.
Excellent exposures of Java Formation shales on the left.

Bridge crossing the South Branch of 18 Mile Creek.
The contact between Java Formation shales and the overlying Dunkirk Shale Member of the Canadaway Formation is exposed near the base of the section to the left. For permission to inspect outcrop, ask owners at house along the creek (driveway to the west of bridge)

Waterfall in creek to the right of road.
Falls is in the Dunkirk Shale. In periods of summer overgrowth, the falls can be viewed from the bridge on Clarksburg Rd., 0.07 mi. back

STOP 1. Creek bed near a sharp turn to left on New Oregon Rd.
For permission to view outcrop, ask owners at the second house past barn along the turn and also ask at the house on the left past the private bridge on the driveway to the outcrop (Fig. 8)
Walk down the driveway toward the private bridge over the South Branch Eighteen Mile Creek. The creek bed directly below the bridge, as well as the creek bed upstream, (south) displays a "typical" exposure of the South Wales Shale Member of the Perrysburg Formation. The stratigraphic column for the South Wales Shale Member at this locality is portrayed in Figure 3. The contact between the basal sandstone of the South Wales Shale Member and black shales of the Dunkirk Shale Member is exposed at the waterfall north (downstream) of the bridge. The upper surface of the basal bed (exposed directly beneath the bridge) displays prominent straight to sinuous-crested ripples (Bouma Tc). The sandstone bed that forms the cap rock of the waterfalls upstream (south) from the bridge also shows prominent ripples, as well as orthogonal grooves.

View of upper portion of the South Wales Shale Member
View of upper portion of the South Wales Shale Member of the Perrysburg Formation on the right.

View of waterfall on right from bridge.
This falls is also in the Dunkirk Shale Member of the Perrysburg Formation.

STOP 2. Much of the ravine on the south of road.
For permission to view outcrop, ask owners at: 10983 Blanchard and also at two homes at Route 16 (see road log below and Fig. 8).
This stop consists of much of the ravine (indicated on Figure 8) south of Blanchard Road. We will walk south from the parking site to the ravine via farmers' roads, then logging roads, and finally deer trails. We will walk down (east) the ravine and come out on Rte 16. This stop displays a complete section from Nunda Sandstone Member at the base near Route 16 to South Wales Shale Member near the top of the ravine. We will hand out a measured section of this locality on the field trip. In the South Wales Shale Member section, notice that the basal sandstone is no longer prominently rippled, unlike the same sand at STOP 1 to the west; rather, it is massive to planar bedded (Bouma Talb). The transition from rippled to massive/planar occurs between this section and that exposed at optional stop 3. In the Nunda Sandstone Member note the escape burrows (vertical worm burrows) and undulatory bedding.

STOP 3. (optional)
To view outcrop, ask owners' permission at 11025 1/2 Blanchard Rd. The owners need proof of self insurance or a signed statement releasing them of all responsibility.
Walk south from the A frame house (west of the owner's house) to the waterfall in the ravine that is closest to the Blanchard Road. This stop displays a fairly complete section of the South Wales Shale Member. Although we are about 22 km east-northeast of STOP 1, the general appearance of the sandstone beds in the South Wales Shale Member remains the same as that at STOP 1, including the prominently rippled basal sandstone.

Residence of landowner on right for permission to view Stop 2.

Residence of landowner #3 on right for permission to view Stop 2

STOP 4. (optional)
For permission to view outcrop, ask owners at house adjacent to creek section (1437 Mill Rd). The owners need proof of self insurance or a signed statement releasing them of all responsibility (Fig. 9).
This stop displays the upper sandstone of the Nunda Sandstone Member along the north wall of the ravine immediately west of the road. Note that its appearance (e.g., thickness) has not changed significantly from the Nunda exposed at STOP 2, some 10 km to the southeast. However, this sandstone bed abruptly pinches out about 3 km south of here (in a ravine 2 km south of here the sandstone is still a meter thick, but in an adjacent ravine at Pipe Creek 4 km south of here, the Nunda is nonexistent).

Bridge crossing the West Branch of Cazenovia Creek.
Exposures of the Angola Shale Member of the West Falls Formation are seen in the vertical cliff face to the right.

SatF: BEACH PROCESSES AND COASTAL MORPHOLOGY ALONG A RECURVED SAND SPIT: PRESQUE ISLE, PENNSYLVANIA
KENT TAYLOR and RAYMOND BOYCE
(Mercyhurst College)
INTRODUCTION
Presque Isle is an 11 km long recurved sand spit on the south shore of Lake Erie partially enclosing Pennsylvania's only recreational and commercial shipping port, Presque Isle Bay and the City of Erie (Figure 1). A new $15 million system of detached breakwaters is presently under construction along the lake side of the Presque Isle beaches (Figure 2). The U.S. Army Corps of Engineers and the State of Pennsylvania are sharing the cost of this Shoreline Erosion Control Project. A great diversity of coastal engineering structures have been built along Presque Isle dating from the early 1800's to the present (Figure 3) and beach nourishment has been ongoing since 1955 (see Thomas and others, 1987, p. 33-38). The estimated cost of erosion control including beach nourishment from 1829 is $32 million, of which $20 million was spent since 1975. It is hoped that with the completion of the breakwaters the Presque Isle maintenance and nourishment costs will be reduced by $1 million per year for the next fifty years (personal communication Dale Hamlin, Pennsylvania Bureau of Water Projects, 1990).
The U.S. Corps of Engineers and the State of Pennsylvania have shared the responsibility of protecting Presque Isle from significant erosion. From the U.S.Corps of Engineers perspective the primary goal has been to ensure that the peninsula will continue to protect the Port of Erie. Only recently have the beaches on the lake side of the peninsula played a significant economic role for the City of Erie due to their immense recreational potential. Some conflicts have arisen recently between those who see the primary goal of erosion control projects as maintenance of recreational beaches and others who continue to pursue the long standing goal of harbor protection. Some progress has been made toward addressing both issues. One example is the recent spreading of a fine-grained sand layer over the beach replenishment materials selected for maximum cost effectiveness for erosion control (the so-called dirty sand and gravel taken yearly from upland gravel pits).

SatF: BEACH PROCESSES AND COASTAL MORPHOLOGY ALONG A RECURVED SAND SPIT: PRESQUE ISLE, PENNSYLVANIA

Overflight Departure Point

New condominiums on left.
Pile of large sandstone blocks is remains of 1948 vintage seawall, which was removed during condo construction.

Entrance to Presque Isle State Park.
Bike path leaves road on right.

View of Presque Isle Bay (Erie Harbor) to right.

Extensive swampy land.

Park headquarters building on right.

Niagara boat launch area on right.

Cookhouse Pavilion. Lunch Stop

Waterworks on right.

Experimental electric generating windmill on right.

STOP 1. Beach 6: Neck Segment
This stop is located to the west of Beach 6 between Groins 10 and 11 on the Neck segment of Presque Isle (Figure 11). Beach 6 is at the downdrift end of the groin field constructed to stabilize the Neck as part of the cooperative shore protection program beginning in 1954. This area is one of the erosional hot-spots along the peninsula's neck. Each year approximately 75,000 cubic yards of sand are dumped at this site as part of Presque Isle's annual beach nourishment program. This sand usually disappears by December after the intense storms in the fall.
Storm waves commonly arrive nearly perpendicular to this section of the Presque Isle shore. A large portion of the wave energy is transformed into storm water-level set-up against the beach. This results in a stratified current pattern with net lake-ward underflow along the bottom. During severe storms with strong winds from the southwest, high waves superimposed on elevated lake levels commonly wash over the roadways and sometimes entirely across the spit into the bay.
Within the groin field the nearshore slope is steep. Bar forms include an outer bar and an inner bar separated by a bar trough. The inner bar is linear or crescentic in form. The outer bar is crescentic with lows or saddles separating the 400-1000 m segments. The beaches within the groin field are narrow and generally erosional. Downdrift offsets of the beaches adjacent to the groins demonstrates the net west to east transport of sediment called littoral drift. Other engineering structures such as rip-rap revetments significantly influence the character of the beaches.
Results of a comprehensive nearshore current study and native-sand tracer study completed prior to breakwater construction on the inner bar system (Sonnenfeld, 1981) and the outer bar-trough system (Taylor, 1981) indicate the following nearshore dynamics for storm events (wave heights greater than 60 cm):
(1) Sediment from the beach and the inner bar is transported lake-ward towards the outer bar trough by rip currents located on the updrift sides of the groins, rip currents associated with cell circulation systems located between the groins and the net lake-ward flow near the bed.
(2) Sediment from the lake-ward flank of the outer bar and the bar crest is transported toward the trough inside the outer bar (outer-bar trough) in response to currents generated by incident waves shoaling and breaking on the outer bar.
(3) Sediment within the outer bar trough is transported by an eastward directed shore parallel current within the trough producing an effective mechanism for sediment bypassing the beaches downdrift of the source areas.
(4)Scouring within the outer bar trough is common during these conditions and results in an increase in the relief of the outer bar.
(1) What effect will the breakwaters have on sediment exchange between the beaches and the nearshore zone?
(2) What kinds of currents will be generated by the interaction of incident waves and the breakwaters?
(3) How much nourishment, if any, will be required to maintain the beaches?
(4) What will be the fate of the outer bar if offshore sediment transport is decreased?
THINGS TO LOOK FOR
* Notice wave height and approach direction with respect to the shoreline orientation.
* Notice longshore current direction and speed and look for evidence of rip currents (e.g. wave suppression in certain areas due to current outflow and suspended sediment plumes)
* Observe the texture of sediments including the beach replenishment materials.
* Observe the effects of engineering structures on beach morphology and wave reflection and refraction patterns.
* Notice the washovers in the backshore areas.
* Notice the newly constructed detached breakwaters. Can you see any difference in the beach behind the structures?
* Zebra mussels

Swampy area on right
Large number of dead trees due to high lake levels during the last several years.

Road to Marina and West Pier on right
Road to Marina and West Pier on right runs along an old dune ridge. It was the old park perimeter road before the 1956 dredging of nourishment material opened the Marina area.

Dunes and beach visible to left.

Entrance to park maintenance area on right.

Lighthouse (built in 1871) on left.
Sidewalk Trail trailhead on right. This concrete paved trail runs along the base of a dune ridge from the lighthouse to the bay shore near the East Boat Livery. It is shown on the 1900 15 minute topographic map, and was originally used as an access route for the lighthouse keepers, who crossed from Erie by boat. It was paved in 1913. The park road originally ran in front of the lighthouse, but was damaged by erosion in 1946, and relocated to its present position in 1948.

STOP 2. Beach 9: Lighthouse Beaches
This stop is located to the east of the lighthouse at Beach 9. The dramatically different morphology and dynamics along this section of the peninsula are a consequence of the change in shoreline orientation with respect to the dominant southwest wave approach direction and the influx of sediment eroded from the peninsula's neck.
The Lighthouse Beaches (Figure 11) are much wider with established multiple vegetated dune ridges on the backshore. Relic coastal dune ridges, separated by swales and ponds dominate the climax forest behind the beaches. The most striking feature of the beaches is the system of large-scale shoreline megacusps spaced at 400-800 m. These. rhythmically spaced features are substantial packets of sand which typically migrate eastward maintaining their identifiable form over periods ranging from months to years. Sediment which is transported along the beach itself occurs within these features. It may be that as little as 20 percent of sediment transported along the Lighthouse Beaches occurs as beach transport; the bulk of sediment transport takes place offshore. As megacusps move eastward so do the rip channel embayments between them. Beach erosion is tied to these rip-channel embayments and consequently it is these pockets of erosion that have been targets of beach nourishment. It has been established that little net erosion or deposition of the lighthouse shoreline occurs through time (Nummedal, 1979).
The nearshore zone morphology of the Lighthouse Beaches is the most complex of the three segments. It includes up to four longshore bars parallel to the beach which are superimposed on transverse bar components and an arcuate bar system (Figure 7). The significantly gentler slope of this multi-barred nearshore zone is a direct consequence of the high rate of sediment supply to this area. The large sediment load for the nearshore zone is largely derived from sources updrift (west of the lighthouse along the erosional neck) rather than the local beaches.
Sediment exchange between the beach and offshore bars is limited to the arcuate bar system and megacusps. Sediment moves eastward along the arcuate bar system with some sediment reentering the beach where the bars attach to the horns of the megacusps. The rest of the sediment continues along the bar system. Sediment is transferred back to the bar system from the beach by rip currents flowing within bar-rip channels emerging from the embayments between megacusps. The entire megacusp system is strongly skewed to the east because of eastward directed incident waves.
Many questions about the spatial and temporal nature of the shore parallel and transverse bar components remain to be answered. For example, the rates, patterns and mechanisms for sediment dispersal in the deeper portion of the nearshore zone are not understood. It is difficult to assess how the detached breakwaters will effect the dynamics of this area.
Things To Look-For:
* Notice the wave height, wave approach direction and shoreline orientation.
* Notice the longshore current direction and speed.
* Observe the texture of sediments at different locations on the beach and backshore.
* The characteristics and spacing of megacusps and inner bars that may be recognized by observing waves breaking over their crests.
* Notice the distribution of pockets of erosion and deposition along the beach and their relationship to beach morphology.
* Notice the vegetated dune ridges and incipient dunes formed by the interaction of vegetation and aeolian activity in the backshore.
*Notice beach ridges and climax forest across the road.

Sunset Point area, beach and lake visible to left.

STOP 3. Beach 10 And East: Gull Point
This stop on the Gull Point segment of Presque Isle (Figure 11) features the beaches east of the prototype breakwaters built at beach 10 in 1978. Depending on the time available we will walk eastward onto Gull Point to see the extensive sand plain and series of accretionary dune ridges.
By this stage in your observations, it must be clear to you that Presque Isle is an eastward migrating spit system that feeds upon itself as it migrates. Within this system, sediment is eroded from the neck, transported across the broad shallow multi-barred nearshore zone of the Lighthouse Beaches and is finally deposited adding to Gull Point, the only net depositional feature along the peninsula. The rapid growth of Gull Point is evidenced by the formation of a series of beach ridges superimposed on recurved spits which wrap around the end of the spit enclosing ponds.
The rapid accretion of Gull Point began in the 1930's possibly in response to the sudden increase in available sand supply from the breached neck in 1917-23, and is continuing today in response to the annual nourishment program. According to the U.S. Army Corps of Engineers (1979) the present volumetric migration rate of 289,100 cubic yards per year reflects the replenishment input which has averaged 259,000 cubic yards per year since 1955. The peninsula's continued eastward migration operates at an annual sediment budget deficit. The present deficit results partly from the spit having migrated to the eastern edge of its underlying platform in response to a longterm rise in lake level (post glacial rise of 1 ft. per 300 yr.). Each future increment of eastern migration of Gull Point requires much larger volumes of sand because the platform itself must prograde into deep water before the spit can be superimposed. Also, the present sediment volume being supplied to the Neck from streams and bluff recession updrift has been estimated at only 30,000 cubic yards per year.(Nummedal, 1984).
The Gull Point beaches receive the lowest annual wave power along the entire outer shore of the peninsula. The orientation of the shoreline is such that only storms with incident waves from the northeast can generate sufficient energy for offshore transport and shoreface broadening. Such storms are infrequent and moderate in strength. This wave climate is such that sediment is kept close to shore maintaining a steep prograding profile.
Because the nearshore slope is steep and the surf zone is narrow only one, or at most two, longshore bars are present close to shore. Because the strongly eastward directed incident waves, rip channels and transverse bar components are strongly skewed to become nearly shore-parallel. This offshore profile is maintained by the prevailing onshore transport of sediments.
The beaches are dominated by megacusps with a spacing of 700-800 m. These megacusps are closely associated with inner bars that commonly weld onto the beaches. The welding bars are much like ridge and runnel systems (swash bar complexes) of ocean beaches in form and behavior. Of course we have no tidal effects here so the dynamics are necessarily different. Migration of megacusps produce rapid changes in beach orientation and beach slope along the Gull Point beaches.
Things To Look For:
* Notice the wave height, wave approach direction, shoreline orientation and longshore current direction and speed.
* Observe the changes in sediment texture with respect to changes in beach morphology and distance from the shoreface. Notice also the heavy mineral concentrations.
* Observe the areas of erosion and deposition along the beach including any evidence of bars in the process of welding to the beach.
* Notice the washovers in areas where the primary dune ridge has been eroded away.
* Notice the different stages of dune ridge formation including the succession of vegetation types that accompanies dune ridge growth.

Thompson Circle loop road on right.

Road to Coast Guard Station on left.

Entrance to Beach No. 11 on left.

Misery Bay on left.
Admiral Perry's fleet returned here after the battle of Lake Erie to spend the winter. The Perry Monument is visible on the point across the bay. Niagara Pond is on the right.

Lawrence Boat Launch on left.

South end of Sidewalk Trail on right.

Entrance to East Boat Livery (Park franchised boat rental area)

Grave Yard Pond on right.

Cross Misery Bay Bridge.

Parking area for Perry Monument on left.

Bike trail crosses road.
Stone rip-rap along bay shore on left. View to left across Erie Harbor to city of Erie.

Entrance to East Pier area parking on left

Dredged harbor area on left is location of the park Marina.
This area supplied much of the initial beach nourishment material in the 1950's. Range lights on left and right are navigational aids for marking the marina entrance.

Bridge over inlet to Long Pond.

This is an area of frequent winter washovers and dune migrate across road.

Pettinato Beach entrance on right.

Waterworks lagoons on right, picnic area on left.

Beach No. 6 entrance on right.

Modern restrooms on right (Barra Beach access).

Beach No. 1 entrance on right.

SatG: A FEW OF OUR FAVORITE PLACES; AN ENVIRONMENTAL AND GEOLOGICAL EXCURSION IN CHAUTAUQUA COUNTY
Richard A Gilman and Jack Berkley
State University of New York College at Fredonia
Fredonia, N.Y 14063
This trip will focus on a variety of geological features and processes of particular interest to students, rather than on results of current research on a single topic. General topics include environmentally important sites, geomorphology and glacial geology, and bedrock geology including unusual structural features. The setting for this trip is a portion of the eastern shore of the Lake Erie Basin in southwestern Chautauqua County. Upper Devonian bedrock units (mostly shale and siltstone) are overlain by Wisconsin-age glacial drift, mostly morainal material on the "escarpment" (edge of the Allegheny Plateau), with post-glacial, pre-Lake Erie lake clay dominating in the glacially-scoured lake plain below. Post-glacial erosion has produced deeply incised fluvial valleys, some with rather spectacular gorges. Human economic activities center on agrarian enterprises, with the famous Lake Erie Grape Belt dominating production in the lake valley.
This field trip will take us to (in order of stops) [1] a "pop-up" structure in Canadaway Creek near the SUNY, Fredonia campus, [2] an active and [3] inactive fly ash waste disposal site, [4] Lake Erie State Park (lake erosion, bedrock features, glacial till), [5] a glacial lake Whittlesey beach deposit quarry, [6] a scenic overview from the "escarpment" of the Lake Erie basin (lunch), and [7] a scenic-educational hike into the Chautauqua Gorge to see bedrock and glacial features, including a pre-glacial buried valley. We strongly advise that all participants bring waterproof boots, or for the more adventurous, sneakers. This apparel will be essential particularly on STOP [7] which requires considerable stream wading. Fig. 1 is a map showing locations of all stops.

SatG: A FEW OF OUR FAVORITE PLACES; AN ENVIRONMENTAL AND GEOLOGICAL EXCURSION IN CHAUTAUQUA COUNTY

STOP 1. Pop-Up Structures
Pop-up anticlines were recorded as early as 1886 by G.K. Gilbert in otherwise flat lying Devonian strata of New York and Pennsylvania (Gilbert, 1886, 1888). He attributed these structures to "thermal expansion of surficial rocks following glacial unloading" (Sbar and Sykes, 1973). Since that time others have reported similar structures (Cushing et.al., 1910, Williams, H.R. et al.,1985, and Adams, J., 1982) in which the axis of the pop-up generally strike N-S or NW-SE. Sbar and Sykes (1973) reviewed the evidence favoring a contemporary ENE to E-W maximum compressive stress for much of the Great Lakes region of North America (Fig. 2), and suggested that "the release of a vertical load in the presence of a large horizontal compressive stress of non-glacial origin, however, may be responsible for the formation of the pop-up... "
Pop-up anticlines in northern Chautauqua County generally have a NW-SE to N-S strike (STOP 7) but some have been found that strike E-W (STOP 1). At this exposure notice that the shaley beds and even some siltstone beds are bent at the fold. Does this imply a certain degree of ductile deformation, and if so what was the mechanism of deformation and when did it occur? If the northwest trending structures are the result of the ENE regional compressive stress, how are the E-W trending pop-ups explained? Coates (1964) describes a 7 foot high, NW striking pop-up that developed overnight in a quarry floor in Ontario. Note that the STOP 1 fold is directly overlain by unconsolidated floodplain deposits and the constituent shale bedrock was, no doubt, subjected to fluvial erosion until "recently" (?). Because this fold represents a positive topographic feature it should be highly susceptible to erosion; note that where the fold crosses the present stream bed it has been planed off completely. Thus, if the Canadaway Creek valley is a post-glacial feature, the STOP 1 fold is probably a fairly recent feature (post-glacial), as an older fold (say; Paleozoic age) should have been eroded down to the current erosion level of the bedrock. We will compare the structural properties of this fold to folds of probable glacial origin at STOP 4 (Lake Erie State Park).

STOP 2. Niagara Mohawk Fly Ash, & Bottom Ash Disposal Site
(permission to visit this facility may be obtained from Mr. Jacob (Dav) Guziac, NiMo, 106 Point Dr. North, Dunkirk, NY 14048 716-366-2885)
The Niagara Mohawk site occupies land that formerly included, the Fredonia Airport on Van Buren Road (Fig 3). It primarily receives ash waste from the Dunkirk Steam Generation Plant located near Point Gratiot, Lake Erie, within the city limits of Dunkirk. This plant began electrical generation in 1949 using Pennsylvania bituminous coal as fuel. It generates 600 megawatts of power fired by about 5,000 tons of coal per day. Originally the ash produced at the plant was mostly "bottom ash", the same "clinkers" or coal cinders produced by home, coal-fired furnaces. However, in 1973 new and more efficient electrostatic precipitators ("scrubbers") were constructed in the exhaust chimneys resulting in cleaner air, but creating addition solid wastes in the form of "fly ash". It is this fine grained fly ash that accounts for the majority of wastes currently dumped at the Dunkirk disposal site. An average of about 450 tons of fly ash deposited at the site every working day (Sunday excluded). Some bottom ash is also dumped at the site (avg. 1/90-2/90 was 130 tons), although much of this is bought by the Town of Pomfret for use as road aggregate. The disposal site also receives some wastes from an oil-fired plant in Oswego.
Of obvious environmental concern is the efficiency of safeguards designed to prevent aqueous leachates at the disposal site to contaminate local surface and groundwater supplies. This is controlled for the most part by clay and plastic bottom liners. Leachates are directed toward an artificial pond ("Sed Basin" in Fig. 3) that is frequently monitored for contaminants (see Table 1). Water from this pond is allowed to flow into a nearby creek after testing shows it to be free of significant contamination. Groundwater is also monitored by a series of test wells (Fig. 3) located around the perimeter of the site. Dust abatement is performed by watering trucks that obtain water from a larger artificial pond adjacent to the settling basin (Fig. 3).

STOP 3. Frame Trucking Co. Reclaimed Disposal Site.
We will visit the a nearby "reclaimed" site owned and formerly operated by the Don Frame Trucking Company (Fig. 3). This disposal cell was active from 1971 to 1985.
Metzger (1974) noted that groundwater samples taken near the active fly ash disposal cell at that time (Frame site; STOP 3) showed that efforts to contain groundwater contamination were successful. However, he also showed that water samples collected near an older dump site (near the entrance on Van Buren Road) were contaminated with high concentrations of iron and manganese. It is safe to conclude that these metals were derived by leaching of the old fly ash materials by groundwater, and that other heavy metals (not analyzed) may also have shown higher-than-background abundances. Table 1 shows that containment techniques at the current cell are successful in keeping contamination restricted to the disposal site. All metal values are quite low and abundances for organics are all below detection limits. Hopefully, this situation will be maintained in subsequent years, but this remains to be seen.

STOP 4. Lake Erie State Park
The lake shore here offers us the opportunity to study several features of interest: (1) jointing developed in the South Wales member of the Canadaway Formation... we will also discuss additional studies on jointing in this area and across the Allegheny Plateau, (2) shoreline erosion... recent problems of severe erosion rates associated with high lake levels and how the U.S. Corps of Engineers resolved the problem at the bath-house, (3) a beautiful exposure of glacial till overlying shale bedrock along with lacustrine deposits overlying the till, and (4) septarian concretions.
JOINTS: In recent years joint patterns across the Allegheny Plateau have received considerable attention (Engelder, 1982, 1985; Engelder and Geiser, 1980; Gross, 1989). Fig. 4 shows results of these studies. Of particular interest is the noticeable change in dominant joint orientation from northwest to northeast that takes place in southern New York and northern Pennsylvania (Fig. 4C). There is also a clear need for additional data from western New York. This will in part be addressed by our discussions here at STOP 4. The strong ENE set of extensional joints (Fig. 4B) is interpreted as having formed in a neotectonic stress field with an ENE direction of maximum compressive stress (Engelder, 1982). As summarized by Gross (1989), "These features are thought to form near the earth's surface as the result of uplift and erosion and are controlled by the orientation of the contemporary tectonic stress field."
At Lake Erie State Park the South Wales member of the Canadaway Formation is well exposed at water level. It displays an abundance of joints oriented approximately N 50 W and N 30 E. Fig. 5C is a rose diagram of 134 joints measured at this location.
In preparation for this field trip RAG undertook a reconnaissance study of joint patterns in each member of the Canadaway Formation in northern Chautauqua County. Results are shown rose diagrams in Fig. 5. These diagrams show that in all cases there is at least 1 strong NE joint set (N 25-35 E and/ or N 65-70 E). In addition a N 30-40 W set and/ or a N 50-60 W set is present in some units. However they are not consistently present in all exposures of these members. For example, the Northeast shale in Canadaway Creek has abundant NW joints, but very few are seen in Chautauqua Gorge (Fig. 5I & 5J).
Using the criteria that younger joints abut older ones it appears that N 35 W joints are younger than the N 65 E set and N 70 W joints are older than the N 65 E set. Gross (1989) found that ENE joints in the Lockport dolomite are consistently younger than NW sets.
How does all of these relate to earlier joint studies on the Allegheny Plateau? ... that will be part of our discussion.
SHORELINE EROSION: Wave-induced erosion along the Lake Erie shoreline is a problem that has attracted a great deal of attention in recent years. From a human standpoint shoreline erosion destroys valuable lakeshore property and jeopardizes the structural integrity of buildings and other near-shore constructions. Sand beaches are also affected by increased erosion during high-water times, with sand being carried farther out in the basin during times of increased wave activity. Fig. 6A shows that the year 1986 experienced especially high water levels in Lake Erie. In fact that year set an all time record, exceeding previous highs measured in 1973 (573.51 feet). The highest level recorded in 1986 was 573.70 recorded during the summer. Levels have generally decreased since that time and were especially low during the drought of 1988 (Fig. 6A). In fact, the most recent Army Corp of Engineers lake level report suggests that lake levels will remain well below average during the summer of 1990. During times of high lake levels erosion rates increase because waves are more likely to impinge upon easily erodible glacial sediments that overlie bedrock. During low water periods waves contact bedrock which erodes less efficiently than glacial till. In addition, during low water periods wave energy is likely to be dissipated over a broad area of lake bottom, thus lessening the energy waves can expend on erosion (Metzger, 1974).
Fig. 6B shows the typical lake level pattern over any given year which is to rise during the spring and summer months and decrease during winter and fall. This is, perhaps, fortunate because winter storms can be particularly energetic. Storms at any time of the year cause strong prevailing winds to develop on the lake basin. This results in "setups", a process where water literally piles up on one side of the lake, usually the eastern or southern side. Storm setups combined with unusually high water levels can cause considerable erosion along the lake shore, and may destroy beaches. Sand carried out to deeper levels usually returns, however, as lake levels return to more normal values (Metzger, 1974). Fig. 7 shows that the Lake Erie shoreline in western New York is generally subject to light to moderate erosion.
A dramatic example of severe shoreline erosion directly affecting human activities can be observed at Lake Erie State Park. Erosion of virtually unconsolidated glacial till underlying the bathhouse was threatening to undercut this building's foundation. In 1986 the U.S. Army Corp of Engineers proposed an erosion abatement plan to save the building from probable structural damage resulting from this erosional undercutting. The bathhouse, situated on a 25 foot high bluff, was valued at about $300,000 by the state in 1986, so cost considerations dictated that constructing a new facility would be more expensive than saving the old building. The Corp of Engineers, therefore, devised a plan to construct a "rubble-mound" revetment that would extend 250 feet along the toe of the bluff, and extend up the bluff to the bathhouse. The revetment project was subsequently approved for construction. It consists of a gravel fill layer overlain by large limestone boulders. A plastic filter fabric was laid down under this material to keep bluff materials from infiltrating the revetment, and a series of buried plastic pipes aids drainage. The estimated cost of the project prior to construction was $200,000. Fig. 8 shows a map view of the construction plan that was eventually completed in 1988.
GLACIAL DEPOSITS: Bedrock along the beach area is overlain by unconsolidated surficial deposits of glacial origin, deposited during the Wisconsin glacial advance. This material is well-exposed on the cliff face along the beach and consists of buff-colored, unstratified, badly sorted till, overlain in some areas by finely laminated, gray lake clay. The till consists of some recognizable local bedrock material especially in the lower horizons, but also includes pebbles through boulder-size rocks mostly of metamorphic or igneous origin. Some large blocks of relatively coherent bedrock were incorporated into the lower till layers in some areas. These blocks display local folding that may have been induced by glacial movement. We will visit one particularly well-exposed site and compare this folding to that observed in the pop-up structures observed at STOP 1.
Lake clay is exposed in some areas above the till, but has been removed by erosion elsewhere. It is thinly laminated, nearly pure gray clay in many areas but locally is mixed with sand, gravel or pebbles. The layering may represent a response to seasonal depositional conditions (varves), although this is subject to debate. Most varved clays show distinct color differences, apparently absent here. This clay was deposited by one of the precursor lakes to the present Lake Erie, Whittlesey or Warren. Judging from the low stratigraphic position of this clay relative to the till layer, the lake clay was probably deposited be the earlier lake, i.e. Whittlesey.
SEPTARIAN CONCRETIONS: A few hundred feet west of the till exposure, numerous 3 to 5 feet diameter septarian concretions are exposed at water level. According to Pettijohn (1975) the formation of septarian nodules appears to involve development of a nodular body, case hardening of the exterior with dehydration of the interior and generation of the shrinkage-crack pattern, and partial or complete filling of the cracks with precipitated mineral material, thereby producing the vein network of the nodule. Shrinkage and production of cracks imply a gel-like character of the original body.
Ultimately, development of concretions may be related to bacterial fermentation or organic matter during shallow burial. Such reactions apparently generate water, carbon dioxide and biogenic methane. This leads to an increase in the pH of the pore fluids allowing for carbonate precipitation. The carbonate cements which may include calcite and siderite, commonly develop as concretions that may be found intermittently along beds. Some of the nodules, the septarian concretions, have undergone dehydration with accompanying development of shrinkage cracks (Selley, 1988). These cracks are later filled in by precipitation of carbonate minerals (calcite and siderite) from infiltrating hydrous solutions. In addition, the relatively uncommon mineral, barite (BaSO4), is a common accessory mineral in many septarian concretions.

Route 20 lies along the top of the Lake Warren beach ridge
This will be discussed at the next stop.

View of Lake Whittlesey beach terrace at 10 o'clock.

STOP 5. Gravel Pit In Lake Whittlesey Beach Deposits
As the Wisconsin ice front retreated north of the high ground of the Portage Escarpment, meltwater that had previously drained southward was now trapped between the ice margin and the escarpment. This led to numerous small lakes and eventually to the development of three large lakes (the ancestral Great Lakes), Lakes Maumee, Whittlesey, and Warren. Two of these, Whittlesey and Warren, formed beach terraces that are well preserved in Chautauqua County (Fig. 9). Prior to the deglaciation of the Mohawk and St. Lawrence river systems the drainage of both lakes Whittlesey and Warren was westerly. As the northeast outlet channels became ice free Lake Erie was established at its present level. The sequence of deglaciation events for Chautauqua County is shown in Fig. 10.
In the Westfield-Fredonia area, Route 20 lies along the Lake Warren beach and Webster Road along the Lake Whittlesey beach.
STOP 5 is in a Lake Whittlesey beach deposit where the following features should be noted; the style and dip of bedding, composition of the pebbles in the gravels, and the structures and textures within the beds.
Due to post glacial isostatic rebound the elevations of these beach terraces rise fifty feet toward the east between the villages of Ripley and Silver Creek, a distance of about 40 miles.

At about this point we leave the lake plain and proceed up the escarpment.

STOP 6. Thayer Road Overlook
The Lake Erie Basin was likely a low area rimmed on the south by a cuestaform ridge in pre-glacial times_ (Dreimanis, 1969; Gravenor, 1975). The sharp rise in topography in front of this overlook is called the Portage Escarpment that although modified by glacial activity is believed to have formed by subaerial erosion prior to Pleistocene glaciation. Bedrock of the escarpment consists of the Canadaway Formation (Fig. 11). Unlike the Niagara Escarpment to the east, the Portage Escarpment is not capped by the resistant strata but is dominated by shales with interbedded thin siltstones. Muller and Fahnestock (1974) asked, "If the topography be truly cuestaform, where are the resistant capping strata responsible for the scarp which is 700 to 1100 feet high in eastern Chautauqua County?"
The overlook is situated on top of the Lake Escarpment Moraine, a moraine complex that Muller (1963) correlates with the Valley Heads Moraine in the Finger Lakes region. This is the result of a stationary ice front at about 14,000 B.P. The moraine is a prominent feature from Northeast, PA to east of Gowanda, NY.

Route 20 follows along the Lake Warren beach as we proceed toward Westfield.

Bridge over Chautauqua Creek.

STOP 7. Chautauqua Gorge Hike
Park at the end of the road, across from gas well.
Note: The hike will take about 3 hours and much of the time we will be walking in the stream. Consequently you should have footwear that you don't mind getting wet and that has good traction. These rocks are extremely slippery when wet...USE CAUTION.
As the ice margin retreated northward from the Portage Escarpment, north draining streams such as Chautauqua Creek were established. Some of these streams carved deep gorges across the escarpment, in most cases carving their channels into the Devonian bedrock, but in other instances exhuming parts of pre-glacial (or interglacial) valley systems (Muller, 1963). These streams head less than 10 miles south of the Lake Erie shore. Farther south streams drain southward into the Allegheny River.
Stratigraphic units we will see on our hike are the Dexterville (siltstone), exposed where we first enter the creek; the overlying Ellicott, seen high on the steep valley walls; and as we walk downstream we will cross into the Northeast (shale) that lies beneath the Dexterville (Figs. 11 & 12).
We will walk approximately one mile downstream examining the following features: The stratigraphic influence on joint development, pop-up structures, fossils from the Ellicott, cone-in-cone concretions, and a pre-glacial channel filled with kame gravels. We will also consider the sedimentology of this interval of the Canadaway Formation.
JOINTING: Systematic joints are absent in the Dexterville member but abundant in the Northeast shale. A rose diagram of 70 joints is shown in Fig. 5J. Most are approximately N 45 E.
POP-UP STRUCTURE: One well developed pop-up will be examined. It strikes N 27 W parallel to a localized northwest joint set. Dips at the crest of the structure are 15 SW and 6 NE. The structure is about 20 feet across and has an amplitude of about 2 feet. This example is quite different from the anticline seen at Stop 1 in that there is no bending at the hinge.
CONE-IN CONE CONCRETIONS: Cone-in Cone concretions are known from several locations in western New York and Pennsylvania from the Northeast shale member of the Canadaway Formation. A study by Gilman and Metzger (1967) found that:
"The cone-in-cone concretions examined in this study occur as two hemispheres of cones separated by a layer of bedded siltstone. Microscopic examination reveals both a bladed and radial extinction pattern in the equigranular calcite constituting the concretion. The cones are disrupted by two systems of fractures: those termed major form the boundary or the cones, those termed minor penetrate the cones and are associated with the formation of clay rings which encircle the cones.
X-ray analysis shows all of the CaCO3 in the concretions to be calcite. The predominate clay minerals are illite and chlorite. The concentration of mixed layer clay is greater within the concretions than in the adjacent sediments.
The cone-in-cones are thought to have originated from a syngenetic concretion of fibrous aragonite. The conical structures are believed to have formed while the surrounding clay materials were still plastic, and that clay was introduced along the major fractures as the cone-in-cone structure developed."
A cross section of a typical concretion is shown in Fig. 13.
PALEONTOLOGY AND SEDIMENTOLOGY: Faunal communities of the Dexterville and Ellicott members were studied by Burrier (1977). His table of fauna from various lithologies within the Chadakoin Formation is shown in Table 2. He concluded that these strata represent regressive and transgressive facies of delta front and prodelta environments. Miller and Lash (1984) consider the Northeast shale to be a thickening-, thinning - upwards sequence of turbidites deposited from unconfined sheet-like turbulent flows, perhaps originating from storm activity on the shelf to the east.
PRE-GLACIAL VALLEY. The topographic map (Fig. 14) of the part of Chautauqua Creek known as THE GULF shows a pronounced change in valley shape: a narrow steep walled bedrock gorge in the region where we will start our hike, to a wide flat floored valley about a mile downstream. The north end of this wide valley segment is again constrained between narrow bedrock walls. Post glacial erosion by Chautauqua Creek has carved a channel that in part cuts across a pre-glacial valley that was subsequently filled with glacial deposits. Muller (1963) interprets these as kame deposits. The extent an orientation of the older channel is not certain.

SunA: SUBMARINE EROSION AND CONDENSATION IN A FORELAND BASIN: EXAMPLES FROM THE DEVONIAN OF ERIE COUNTY, NEW YORK.
CARLTON E. BRETT
Department of Geological Sciences
University of Rochester
Rochester, New York 14627
GORDON C. BAIRD
Department of Geosciences
SUNY College at Fredonia
Fredonia, New York 14063
Geologists have long recognized the importance of unconformities in the stratigraphic record. Sloss (1963), for example, used six widespread unconformities to subdivide the North American stratigraphic succession into five major sequences or megasequences. This seminal work was, in some ways, the forerunner of sequence stratigraphic analysis which has recently resulted in a revitalization of stratigraphy (see articles by Vail and Mitchum, 1977; Vail et al., 1977; Posamentier et al., 1988; Van Wagoner et al., 1988; Baum and Vail, 1988; see Fig. 1). It is generally accepted that the stratigraphic record is highly incomplete and that much time is represented at some bed contacts. However, it is not always clear where these surfaces exist within stratigraphic sections. Many erosion surfaces, particularly in marine mudstone successions, are very subtle and can only be recognized with detailed observations. Nonetheless, many such surfaces are traceable over vast areas, forming the basis for a new dynamic view of stratigraphic processes within epicontinental sea and foreland basin settings.

SunA: SUBMARINE EROSION AND CONDENSATION IN A FORELAND BASIN: EXAMPLES FROM THE DEVONIAN OF ERIE COUNTY, NEW YORK.

STOP 1. Type Section Of Dunkirk Shale Member, Point Gratiot At Dunkirk.
Turn right onto Cedar Beach Parking area. Niagara Mohawk coal-powered generating station straight ahead (to NE). Proceed north on foot for approximately 500 feet along beach to northeastfacing lake shore outcrop near lighthouse museum at Point Gratiot.
This outcrop is excellent for viewing the sharp contrast between the grey-green bioturbated, but non-shelly, mudstone of the Hanover Shale Member and the black, organic-rich, laminated facies of the overlying Dunkirk Member. A conformable, bioturbated contact between Hanover and Dunkirk can be seen below the 15 to 18 cm thick (6 to 7 inches) basal Dunkirk black bed which dips southward below the water at this section. However, a sharp, erosional discontinuity with associated reworked debris marks the contact between the 12-13 cm (5 inch) thick grey-green bioturbated bed above the 18 cm (7 inch) basal bed and the over lying continuous black shale succession .
Close examination of this contact shows that abundant reworked (detrital) pyrite is present along it with lesser amounts of carbonized wood, conodonts, fish bones, and pyritic goniatite steinkerns (Baird and Brett, 1986a); much of this material is probably derived from the 12-13 cm (5 inches), grey-green mudstone unit which is conspicuously rich in pyrite cemented and overgrown burrow tubes, although the abundance of wood suggests that the basal few inches of the overlying black shale is unusually condensed, recording the descent of numerous logs from the water surface over a long period of time. This lag unit also records bioturbation, which at this section, was sufficient to flux the broken pyritic tubes into random orientations.
As this discontinuity is traced northeastward to the vicinity of Java Village, Wyoming County, more and more beds progressively appear beneath it such that this break passes essentially to extinction (see Fig. 5; Baird and Lash; FIELD TRIP SAT. A, this volume). Instead several black shale beds alternating with bioturbated and non-bioturbated grey-green mudstone make up an intervening sequence several meters-thick. Most of the thin black shales, however, display minor diastemic basal contacts with the grey-green beds marked by minor detrital pyrite. Collectively, these diastems downcut underlying units as they are traced southwestward such that higher discontinuities downcut, through lower ones until only a single 5 inch (12-13 cm) grey-green bed remains at this locality. This illustrates the pervasiveness of submarine erosion associated with the transgressive grey- to-black facies change beneath even very thin black shale units. It also illustrates the distinctive character of condensed sedimentary deposits involving alternations between dysoxic and anoxic facies. For additional information about this outcrop, see Baird and Lash; FIELD TRIP LOG SAT A: STOP 2 (this volume).

Dunkirk Harbor Complex visible (to left) for next mile.

Cross Walnut Creek.
Hanover-Dunkirk contact is at base of bridge. Stebbins Road bridge (being repaired to right) collapsed in 1987, killing one person, when an overweight vehicle caused the bridge to plunge.

Cross Silver Creek, Dunkirk Shale at base of bridge.

Dunkirk Shale above Hanover Shale in Thruway cut
Dunkirk Shale above Hanover Shale in Thruway cut immediately beyond (downhill from) the Silver Creek exit.

Cross Cattaraugus Creek floodplain.
Sand and gravel pits have been opened on this bottom in the vicinity of the Thruway.

Cross Cattaraugus Creek. Begin to cross Seneca Indian Reservation.

Cross Big Sister Creek.
Angola Shale Member of West Falls Formation exposed below bridge.

Cross Eighteenmile Creek.

STOP 2. Middle And Upper Devonian Marine Deposits Along Eighteenmile Creek.
Turn right onto first side street north of Route 5 bridge. Park vehicles and proceed down path at end of street to large cutbank section on north side of Eighteenmile Creek 200 ft. east of (upstream from) Route 5 bridge.
This large outcrop shows to maximum advantage the Tichenor Limestone, the overlying Windom Shale Member, and the major discontinuity at the top of the Windom (marked by North Evans bone-conodont-rich debris) which marks the base of the Upper Devonian series in this area (Figs. 3, 4A). We will see the North Evans to better advantage at the next stop (see STOP 3) and will, thus, focus on the Tichenor and basal Windom shale at this stop.
The Tichenor is a 0.7 m (2 ft.)-thick, widespread crinoid-brachiopod grainstone-packstone unit which is also notable for large corals (Heliophyllum, Eridophyllum, Favosites), large bivalves (Plethomytilus, Actinopteria) and large fragments of the trilobite Phacops. As is obvious from the texture, this is a medium to high energy deposit which may have accumulated within the depth-range of fair-weather wave-base. It is also extremely condensed and time-rich; in the western Finger Lakes region, deposits equivalent to the western Tichenor (mostly Deep Run Shale Member) reach a thickness of almost thirty five meters. Through a combined affect of westward stratigraphic thinning and westward lateral facies change from mudstone to shelly carbonate, the Deep Run is replaced by very thin clean skeletal carbonate in Erie County. The base and top of the Tichenor at this locality are sharp, reflecting erosional processes. The base marks a major disconformity separating deposits of the Ludlowville Formation from the overlying Moscow Formation; the Jaycox Shale Member of the Ludlowville Formation is progressively bevelled below this contact from the Genesee Valley westward such that only the base of the Jaycox is visible at Buffalo Creek in eastern Erie County and none is visible west of the north branch of Smoke Creek in south Buffalo. This bevelling was produced by a major regression event which caused synchronous submarine (and possibly subaerial) erosion in central and eastern New York State (see McCave, 1973; Baird, 1979; Baird and Brett, 1981) and this contact may be a bona fide sequence boundary. Examine overturned Tichenor blocks for large, abrasion-enlarged, hypichnial trace fossil markings produced by large arthropods; these resting- (or dwelling) excavations into firm Wanakah marine muds were later filled-and casted by the Tichenor skeletal sands.
The top of the Tichenor is also marked by a submarine discontinuity, perhaps of similar hiatal magnitude. Submarine erosion that preceded deposition of the Windom, removed most of (or all of) three units (Deep Run-equivalent carbonate beds, Menteth Member, Kashong Member) which overlie the Tichenor east of Buffalo. This erosion produced a submarine hardground at this locality and at other western Erie County Tichenor sections). Examine this surface closely for auloporid corals and crinoid holdfasts which encrust this contact and for the presence of phosphatic nodules and steinkerns reworked from below (see Brett, 1974; Brett and Baird, 1974 for additional description of this surface).
The overlying Windom Member records transgressive deepening to quiet, open-shelf conditions minimally affected by storm wave reach. Fifty centimeters (16 in.) above the base in a unit (Bayview Coral Bed) which is rich in large brachiopods, particularly Spinatrypa, and which locally yields large rugose corals, including Cystiphylloides and Heliophyllum along this bank. Above it is a calcareous mudstone unit (Smoke Creek Bed) which is well known for complete enrolled and outstretched specimens of the trilobite Phacops rana (see Brett and Baird, 1982 for additional information on this unit).

Cross Weyer Creek.
Fossiliferous Middle Devonian Wanakah Shale exposed mainly downstream (north) of Route 5 bridge.

Cross Amsdell Road
Amsdell Creek, further up Amsdell Road, has been an important source for conodonts and fish fossils from the North Evan bone-conodont bed.

STOP 3. North Evans Bone Bed And Genundewa Limestone
Park on shoulder pull-off just south of the railroad tracks . Proceed on foot 0 .3 mile southwest along a path border ing tracks to the abandoned Lehigh Cement Co. Shale quarry which is southeast of the tracks.
This abandoned shale pit, developed by the Lehigh Cement Co. as a source of claystone for the mill (now defunct) in Lackawanna, contains a stratigraphic succession from the Middle Devonian in the Upper Devonian. The Quarry walls about 16 m (50 ft) high expose the Upper Devonian Middlesex-Cashaqua Shale. The quarry is floored mainly by the shaley upper contact of the Genundewa limestone and the West River Shale. In a narrow pit the Genundewa is breached and a section extends down some 2.5-3 m (8-10 ft.) to, or just below, the Amsdell (Praeumbona) bed of the Windom shale. The Windom here is in contact with the North Evans Limestone and the contact is an erosion surface showing a characteristic "rip-up" horizon. We will focus on lag deposits (North Evans Bone-Conodont Bed) associated with an erosional contact between the grey Windom Member (Givetian) and the overlying Genundewa Limestone of Late Devonian (early Frasnian) age. For additional information on these units, see: Sass, 1951; Huddle, 1981; Brett, 1974; Brett and Baird, 1982; Baird and Brett, 1986a.
The North Evans Limestone, or "Conodont bed" of older literature, is typically a 0.5 to 6 inch- thick packstone- grainstone unit composed of reworked crinoid ossicles, conodonts (including many mixed from older zones) fish teeth and armor fragments, as well as calcitic brachiopod, coral, and trilobite fossils derived from the underlying Windom or from intervening beds now removed. Conspicuous within the North Evans at this locality and also at the abandoned Penn Dixie Shale Pit at Bayview, New York (see Brett and Baird, 1982: STOP 2) are reworked limestone concretions from the underlying Windom. These are often stacked like shingles and they typically have a green exterior patina of glauconite as well as surface dissolution pits produced following exhumation on the seafloor.
The overlying Genundewa Limestone is composed almost entirely of Styliolina fissurella, a problematic millimeter-long conoidal calcitic shell which may be of tentaculitid affinities or the shell of an unknown protistan organism (Yochelson and Lindemann, 1986). Wood debris, goniatitid and orthocerid cephalopods, and the bivalves Buchiola and Pterochaenia comprise the remainder of a low diversity biota. The Genundewa appears to be a classic example of the pelagic Cephalopodenkalk facies of the European and North African literature (Tucker, 1973). As such, it records very slow sedimentation in an offshore, sediment-starved, dysoxic environment.
Although the North Evans rests on fossiliferous Middle Devonian deposits at this locality and would appear to record a simple transgression over the oxic, shell-rich Windom facies, a more complex story emerges when the same bed is viewed in eastern Erie County (see STOP 7); at that section, the North Evans overlies brown-black anoxic facies of the Upper Devonian Penn Yan Shale Member. Hence, an apparent regression with attendant seafloor erosion is recorded after deposition of the Penn Yan and prior to final accumulation of the North Evans lag. The North Evans-Genundewa succession is, thus, a transgressive interval culminating in the deposition of brown-black anoxic deposits of the overlying West River Shale Member which is visible here above the Genundewa Limestone. The North Evans and Genundewa beds probably correspond, respectively, to the transgressive surface and overlying condensed interval in the sequence stratigraphy model (see text); they probably correspond, in part, to other sediment-starved condensed units, such as pebbly greensands and bone beds identified by sequence workers in younger sedimentary systems (see Loutit et al. 1988; Baum and Vail, 1988).
The North Evans lag deposit was apparently reworked into the dysoxic Genundewa outer shelf-slope setting because the encrinitic-bone-conodont hash layer grades upward into Genundewa facies and it underlies the Genundewa throughout Erie County except for exposures along Lake Erie near Highland-On-The-Lake where a brown-black shale subfacies of Genundewa overlies the North Evans (Brett and Baird, 1982). Hence the North Evans is rich in carbonate debris with only minor amounts of detrital pyrite; compare the North Evans with the pyrite-dominated lag that we saw at STOP 1 and, particularly, what we will see in the Leicester Pyrite deposit at STOP 8. Exhumed Windom calcareous shell material was apparently dissolved in the largely anoxic Geneseo basin setting to produce the residual detrital pyrite lag deposit of the Leicester (Baird and Brett, 1986a). Conversely, detrital pyrite was differentially stable in this anoxic or minimally dysoxic setting. Carbonate undersaturation and/or low pH conditions of the basal Geneseo substrate environment are clearly not evident for the North Evans-Genundewa setting to anywhere the same degree. Only where a black shale subfacies of Genundewa directly overlies North Evans along the Lake Erie shore, does the North Evans lag deposit begin to become rich in detrital pyrite, poor in carbonate debris, and laterally discontinuous (lenticular) in outcrop, the way the Leicester always appears.
Fossils to look for in the North Evans are crushing teeth (tritors) of ptyctodonts, an extinct fish order, placoderm dermal armor and jaw fragments, tricuspate cladodid shark teeth, as well as reworked Windom calcareous fossils, including the trilobite Phacops rana.

Cross Morse Creek.
One of many shore area localities in the richly - fossiliferous Middle Devonian Wanakah Shale Member.

Excellent view of Lake Erie, Buffalo-Lackawanna skyline for next 0.6 mile.

Mudstone (probably Wanakah) exposed along Thruway entrance ramp.

Cross Smoke Creek
Ledyard Shale Member exposed to right (upstream) from Thruway.

Cross Cazenovia Creek.
Middle Devonian black Levanna Shale Member exposed upstream (to right) from Thruway bridge.

STOP 4. Submarine Discontinuity Within Middle Devonian Levanna Shale
Pull off from Union Road to the right onto a dirt road and small parking area in vacant lot immediately before bridge over Buffalo Creek and immediately after passing junction of Indian Church Road on the left. Proceed north, on foot to creek. Cross creek if water is not high.
Along this cutbank exposure one can observe two key lithologic divisions of the Middle Devonian Levanna Shale Member of the Skaneateles Formation which are currently unnamed. Just above water level is a calcareous, dark grey-shale division which yields the diminutive brachiopod Ambocoelia and specimens (often complete) of the trilobite Phacops rana. A submarine discontinuity (prominent undulatory outcrop reentrant) separates this lower unit from a fissile, black shale upper division, rich in the brachiopod Leiorhynchus and the aforementioned problematic small conical fossil Styliolina. This boundary is traceable as far east as Oatka Greek near Pavilion in Genesee County. The units in this section record oxygen-deficient outer shelf-to-basin conditions with the lower division recording dysoxic to minimally oxic conditions and the upper division recording lower dysoxic to near-anoxic conditions ("exaerobic" zone of Savrda and Bottjer, 1987) along the seabed.
This discontinuity is distinctive for its distinctly undulatory appearance; troughs between 0.5 and 2.0 meters (1.5-6.5 ft.) in width and between 12 and 45 cm (5 to 16 in) in depth alternate with inter-trough ridges and platforms (Fig. 5A). The troughs are erosional runnels cut into division 1 deposits which are aligned in a nearly north-south direction transverse to the creek channel (Fig. 5B). Some runnels bifurcate but most remain simple and linear. Trough bottom deposits often include calcareous brachiopods, Phacops, and Styliolina debris admixed with fish teeth and dermal plates. These lags are often at channel bottoms but they can occur in axial channel sediments above channel bottoms. Some troughs appear to have been repeatedly filled with sediment and scoured out by currents; these troughs display nested erosional scour surfaces with the sharpness of scour contacts varying from clear to diffuse (Fig. 8C). Evidently some episodes of scour removed only water-rich surface mud while others cut into firm muds.
Clearly, this section records a type of sedimentary condensation where repeated sediment accumulation and scour were dominant sedimentary processes. The overall upward change from division 1 to division 2 appears to be transgressive with the consequent development of an erosional surface; the complex channel-fills appear to correspond to the interval of maximum sediment-starvation and sedimentary condensation which overlies the transgressive erosion surface.
These erosional runnels are probably submarine furrows (sensu Flood, 1983), which are rarely reported from the stratigraphic record. Furrows are believed to form through the action of abrasive horizontal, debris-laden current vortices which scour the bottom into linear runnels within a sustained unidirectional current regime (Flood, l983). The complex "cut-and-fill" histories of the Levanna runnels is a testament to the unidirectional character of the currents which produced them. We are currently studying these features at this locality to establish which way the currents flowed and are also examining all other similar discontinuities to determine if similar runnels are distributed along them.

Cross Cayuga Creek.
Middle Devonian Onondaga Limestone is exposed below bridge and upstream (to east).

Cross Cayuga Creek.

STOP 5. Volcanic Ash Layers In Upper Onondaga Limestone Along Cayuga Creek.
Exposure of Onondaga Limestone along Cayuga Creek (to right). Park on asphalt driveway next to first house on the right. Proceed carefully down slope to south side of creek.
This cutbank exposes two thin metabentonite layers within the upper part of the Onondaga Limestone Formation (Middle Devonian: Eifelian) which comprise part of the "Tioga Ash" (metabentonite) complex of beds discussed in Devonian literature (see Dennison and Textoris, 1978; Conkin and Conkin, 1984; Rickard, 1984; Sparling, 1988). Dennison and Textoris (1978) and Dennison (1983) believe that the tuff originated in what is now northern Virginia and that Devonian prevailing winds carried the winds predominantly westward (in the present sense) into the U.S. midwestern region.
The Cayuga Creek section exposes two metabentonite (K-rich mixed-layer; illite-smectite) beds which are about 16 inches apart with the lower one just below the water level. The higher metabentonite is probably the Onondaga Indian Nation ("O.I.N.") metabentonite of Conkin and Conkin (1984) which corresponds to the "Tioga B" metabentonite of Rickard (1984). The lower metabentonite is probably the Cheektowaga (No .2) metabentonite of Conkin and Conkin (1984); both of these ashes are exposed in the nearby Federal Crushed Stone Corp. Quarry (see Conkin and Conkin, 1984). Although most workers place the boundary between the Moorehouse Member and the overlying Seneca Member of the Onondaga at the horizon of the O.I.N. (Tioga B) ash (see Rickard, 1975, 1984), Conkin and Conkin (1984) place it about 0.5 m higher at the position of a bone bed which is visible in the quarry and which may be present in this section. Uncertainty exists with surface correlations because outcrops in the upper Onondaga-through Marcellus interval are nearly absent in western Genesee and Erie counties. In any case, this section and one in the nearby Federal Crushed Stone Corp. Quarry west of this stop, are the only outcrops showing any part of the Tioga complex of ashes in this region.
The upper metabentonite is a brown mudstone layer with a bronze-yellow micaceous luster which shows some evidence of bioturbation. The lower, less ash-rich unit, contains abundant fossils including rugose corals, bryozoans, pelmatozoan debris, and the trilobite Phacops. The corals, interestingly, are highly abraded and fragmental; this suggests that the lower "ash" might not be the record of a single "mega-eruption" or closely-spaced series of "eruptions" but is rather a condensed unit within Onondaga where pyroclastic debris and other terrigenous sediment became concentrated over a long period of time relative to carbonate. The occurrence of the uppermost Tioga unit ("Restricted Tioga" division of Conkin and Conkin, 1984; "Tioga A" Bed of Rickard, 1984) above the basal-Marcellus transgressive bone bed lag on uppermost Onondaga deposits, suggests a similar story of selective pyroclastic-enrichment associated with sediment-starved bottom conditions (Baird and Brett, 1986a, b).
This brief stop simply illustrates another unusual type of sediment associated with apparent sediment starvation. What is needed is detailed study of sedimentary structures and sedimentary petrography associated with the Tioga deposits to obtain answers concerning sedimentation rates and paleoenvironmental conditions associated with the formation of these enigmatic event-beds.

Cross Cayuga Creek

Cross Cayuga Creek.
Middle Devonian black and dark grey shales of the Oatka Creek Member are intermittently exposed along creek in this area.

STOP 6. "Precursor Bed" At Base Of Middle Dev Stafford Limestone Member
Turn right off of Pardee Avenue into a parking area at Como Park. Proceed on foot about 400 feet west to Lake Road bridge downstream from small dam on Cayuga Creek. .
Along the banks and bed of Cayuga Creek between the dam and base of the small waterfalls lip at the Lake Avenue bridge are exposures of the Stafford Limestone Member, the basal division of the Skaneateles Formation. Downstream from the water falls are intermittent exposures of the black, fissile, organic-rich Oatka Creek Member of the underlying Marcellus Formation which is mostly covered. Near the falls and bridge, the topmost few feet of the Oatka Creek Shale can be examined on the south side of the creek; these uppermost Marcellus beds are dark grey-brown in color and they yield a meager dysoxic biota consisting of the rhynchonellid brachiopod Leiorhynchus, Styliolina, and numerous flattened composite molds of an orthoconic nautiloid.
The Stafford, in Erie County, is a three-part member consisting of a basal, thin, shell-rich muddy limestone bed (Stafford "A" bed), a middle, shaley interval several feet thick which contains nodular micritic concretionary beds, and an upper cherty limestone division, termed the Stafford "B" bed, which is 0.6 - 1.3 m (2 to 4 feet) in thickness and fossiliferous (see Meyer, 1985). In central New York, the equivalent Mottville Member has a shell -rich "A" bed division, succeed by a variably thick middle "shale" division followed by a micritic or siltstone regressive capping unit which corresponds to the Erie County, chert-rich ("B") micritic division visible by the Como Park dam (Grasso, 1986; Meyer, 1985). Despite significant thickness variations of the "middle shale" and "B" bed divisions along the Stafford-Mottville outcrop strike between Buffalo and the Chenango Valley, the "A" bed remains relatively thin, usually between 8 and 30 cm (0.2 and 1.0) foot in thickness, and it is typically a densely fossiliferous calcareous mudstone, both overlain and underlain by sparsely fossiliferous deposits. Although the "middle shale" usually grades upward into fossil-rich shaley micrites of the "B" bed, the "A" bed often rests abruptly on dysoxic to anoxic dark shales as it does at this section.
The "A" bed is a prime example of what we term a "precursor" bed, a layer which records what appears to be a sediment-starved regression event linked to, but clearly preceding, a subsequent longer-term regression which culminates in fossil-rich, regressive, limestone, siltstone, and even sandstone facies (see text). Such beds are enigmatic in terms of existing models of cyclic sedimentation, because they are followed by apparent deepening events associated with synchronous and subsequent influxes of sediment which then produce a regressive filling sequence that culminates in the "B" unit (see text discussion).
At this locality the Stafford "A" Bed yields numerous small brachiopods, including Ambocoelia umbonata var. nana. Truncalosia truncata, Devonochonetes scitulus, and small variety of Tropidoleptus. Other fossils include the large bivalve Panenka, occasional Leiorhynchus, orthoconic nautiloids often encrusted by the reptate biserial tubular organism Reptaria stolonifera, which may have "hitch-hiked" on the living cephalopod (see Baird et al., 1989), and wood debris.
This faunal association is rather typical of precursor beds we have seen in other units and it is nearly identical to that associated with the lower Wanakah "Darien Center" cycle at nearby localities (see Miller, FIELD TRIP SUN C, this guidebook). The diminutive brachiopod assemblage in the Stafford "A" bed appears to represent only a slight increase in bottom oxygenation relative to the underlying Oatka Creek Shale. This assemblage falls between the "Leiorhynchus" and "Ambocoelia-chonetid" biofacies of Brett et al., 1986; Vogel et al., 1986; which is indicative of non-turbid upper dysoxic to minimally oxic bottom conditions (see text).

Cross Cayuga Creek
The lower calcareous part of the Middle Devonian Levanna Shale Member is exposed along creek near bridge. One particularly prominent ledge upstream (east) from the bridge yields occasional excellent enrolled specimens of the trilobite Phacops rana.

Cross Buffalo Creek at Elma, NY.
The Middle Devonian Ledyard Shale Member is exposed in the bed and banks of the creek. Pond Brook, a north-flowing tributary of Buffalo Creek just to the east of Bowen Road south of the bridge crossing has good exposures of the richly fossiliferous Wanakah Shale Member.

Cross the upper end of Pond Brook.

STOP 7. Condensed Carbonate Deposits Of Lower Moscow Fm.
Park near old bridge over Buffalo Creek. Walk out onto bridge for brief overlook, then proceed down bank at west end of bridge and walk about 100 feet north (downstream) to limestone exposure adjacent to the new Bullis Road bridge.
In the low stepped falls interval between the old and new Bullis Road bridges one can observe a succession of thin carbonate beds representing condensed facies of the lower Moscow Formation and uppermost Ludlowville Formation (Fig. 4B). The Tichenor Limestone is visible here as at STOP 2, but it is both overlain and underlain by additional limestone layers; the underlying layer is the basal Hill's Gulch Bed of the largely-bevelled Jaycox Shale Member of the Ludlowville Formation and the overlying beds are in ascending order, the thin, condensed phases of the Deep Run, Menteth, and Kashong members (Fig. 4B). In western Erie County the Jaycox is entirely absent and the overlying complex of condensed units is absent or nearly absent due to further westward bevelling, such that the Tichenor is directly underlain by Wanakah Shale and is overlain by the Windom Member (compare Figure 4A and Figure 4B).
Three discontinuities are present in this section; one at the base of the Hill's Gulch Bed which cuts into the Wanakah Shale; one below the Tichenor which cuts into the Hill's Gulch Bed, and one below the Windom Shale which bevels into a thin remnant of the Kashong Shale Member. The two lower discontinuities are marked by hypichnial, carbonate-casted burrow prods produced by arthropods excavating into underlying muds prior to burial of the discontinuity surface. The sub-Windom discontinuity is marked by phosphatic nodules, phosphatic steinkerns of Kashong fossils, and assorted shelly debris which have been churned and mixed by bioturbation processes during the onset of Windom deposition (Baird, 1978).
This condensed section is almost a "mirror-image" to that involving equivalent beds in central New York (Fig. 4c). Detailed mapping by Baird (1979), Baird and Brett (1981), Mayer (1989), Mayer et al. (1990) shows that each major bed in this outcrop has its time-stratigraphic counterpart in the condensed Jaycox-Kashong succession in the Owasco Lake-Ithaca region. Even the same discontinuities are represented in this latter area, though with the trend of increased bevelling and condensation in the eastward direction instead of westward, as is observed for the deposits here at Buffalo Creek. In the intervening Genesee Valley-Cayuga Lake region, each one of the component divisions in this section balloons into thicker, mud-dominated facies, with each respectively higher division -- Jaycox, Tichenor, Deep Run, Kashong reaching maximum thickness west of that for the previous division (Brett et al., 1986). Hence, this intervening region records a westward-shifting depocenter and an aggregate maximum thickness for the Jaycox-Kashong interval exceeding 35 meters (110 ft.)!
Thus, the "mirror-image"-stacking of corresponding condensed beds in these widely-separated regions is all the more significant given the complexity of depocenter shifts in the intervening region. It strongly suggests that eustatic sea-level changes were responsible for the succession of units, both within the depocenter areas, and on the adjoining shelf regions. Such a pattern makes all the more relevant the discussion of sequence stratigraphy applicability to the New York Devonian System (see text).
From the old Bullis Road bridge one can see the upstream bank of grey chippy Windom mudstone deposits. These rest on the sub-Windom (post-Kashong) phosphate debris-rich discontinuity which can be reached below water-level just upstream from the bridge foundation. Near the top of the Windom bank, the Bayview Coral Bed and the overlying Smoke Creek Bed can be seen. Enrolled Phacops rana can be collected from the Smoke Creek Bed further upstream in the floor of the creek. The giant blastoid Placoblastus sp. is a rare find at this locality; it occurs in the Deep Run-Menteth ledges above the Tichenor.

Cross Little Buffalo Creek.
Middle-Upper Devonian disconformity is exposed downstream from (to northwest of) road crossing.

STOP 8. Middle-To-Upper Devonian Condensed Basinal Deposits
Cross Cayuga Creek. Pull off on to driveway of first house on right beyond the bridge or onto right shoulder of Clinton Road if parking space is limited.
(See also Brett and Baird, 1982: , NYSGA Buffalo, meeting).
At this section ,we will first examine the Leicester Pyrite and its relationship to synjacent beds and then we will focus on the North Evans bone-conodont bed which marks the base of the Genundewa Limestone above the last falls riffle about 120 feet upstream from the bridge.
As with the lag deposit we observed below the Dunkirk at STOP 1, the Leicester Pyrite Member of the Genesee Formation is a detrital pyrite-bone-lag accumulation which directly underlies a laminated black shale unit (Geneseo Shale Member) and which occurs on a submarine discontinuity marking the base of the Geneseo. However, the Leicester is a more dramatic example of this lag type because it is made up of coarser grains and it is typically much thicker than the Dunkirk pyrite bed. Moreover, it rests on the Middle Devonian Windom Shale Member which is a grey mudstone unit usually rich in shelly fossils.
The Leicester is composed of pyrite burrow tube fragments, pyrite nodules, and pyrite fossil steinkerns derived from the Windom Member plus fish bone-and conodont debris of Windom and post-Windom age. These were exhumed under conditions of submarine anoxia or temporary dysoxia by episodic strong currents of unknown character. Reworked Windom (and Tully) lag debris was initially carbonate-dominated reflecting the overall calcitic and aragonitic character of Windom fossils. However, this carbonate debris underwent selective dissolution in a negative pH (or carbonate undersaturated) basin setting; a continuous blanket of reworked Windom carbonate debris, resembling the North Evans deposit at STOP 2, would hypothetically have been reduced to a placer lag of pyrite and bone debris only a small fraction of the original volume. Hence, the laterally discontinuous Leicester lenses represent only a remnant fraction of total Windom debris which was exhumed (Baird and Brett, 1986A). In actuality, during Geneseo time,no continuous carbonate debris blanket probably ever formed because dissolution would have removed carbonate as it was exhumed, allowing no carbonate to build up on the surface.
At this section as at other Leicester localities, some Leicester debris lenses occur within the basal Geneseo, not just at the base. This indicates that pyrite clast-transport occurred during the period of initial black mud accumulation. Moreover, conodont examination by Huddle (1981) shows that the age of the youngest (Genesee-age) conodonts in the Leicester becomes progressively less as this unit is traced westward from the Seneca Valley into eastern Erie County; this westward progressive overlap of Geneseo black mud and lag debris onto the widespread Windom-Genesee disconformity surface tracks the major Taghanic Onlap Event which is now believed to mark a major eustatic transgression in the late Givetian (Johnson, 1970). This overlap cannot be followed westward indefinitely; the sub-Genundewa discontinuity oversteps all lower Genesee strata in central Erie County and the Leicester is apparently cannibalized by this younger erosion surface between Cazenovia Creek and the north branch of Smoke Creek, southwest of Elma, Erie County (Brett and Baird, 1,982; Baird and Brett, 1986A).
Evidence for reworking of Windom Pyrite clasts includes: 1. identical character of Windom and Leicester pyrite grains; 2. evidence of mechanical breakage of pre-formed pyrite grains; 3. abundance of pyritic Windom fossil steinkerns in Leicester; and 4. the reorientation of early diagenetic stalactitic pyrite which formed initially in voids within in-situ Windom pyrite tubes and steinkerns (see Baird and Brett, 1986a, b). Ongoing laboratory sulfur isotope studies indicate a hodgepodge pattern of variable isotopic weights between adjacent pyritic grains which further suggest exhumation and mixing of the pyrite material (see Lyons, 1990).
The mechanisms for physically exhuming and reworking pyrite in what would normally be thought of as a euxinic environment are difficult to reconstruct, given that there is no known modern example of this specific marine condition. Deep-storm waves are always a possibility as are various possible bottom current processes. Baird and Brett (1986A) Baird et al. (1988), offer an erosion model involving transgressive upslope migration of a water density-stratification boundary (pycnocline) along which storm generated internal waves are propagated. Impingement of the pycnocline with the basin slope at an given time allows for the presence of a higher energy wave-shoaling zone coincident with the slope-pycnocline intersection producing a swath of bottom erosion at a critical water depth/contour. Continue transgression would displace the wave-shoaling zone upward allowing basinal black muds and associated bone-pyrite debris to settle on the scour surface produced during earlier internal wave-shoaling. Overall westward Geneseo black mud overlap of the erosion surface may have been interrupted by brief episodes of major current flow and bottom scour events; these may explain the occurrence of Leicester lenses which are interbedded with basal Geneseo black shale deposits.
The Windom-Geneseo contact is a regional disconformity (combined sequence boundary, transgressive and down lap surface) which overlies different Windom beds at different western New York outcrops. Generally, towards the north, the unconformity truncates progressive lower Windom beds. Conversely, towards the south, progressively higher Windom layers appear beneath the Leicester-Geneseo contact (Brett and Baird, 1982). At Cayuga Creek one can observe a Windom shell-rich bed become progressively truncated as it is traced from the falls south of the bridge northward. Near the falls, this Mediospirifer and Pseudoatryparich mudstone layer, probably equivalent to the Fall Brook Coral Bed in the Genesee and Wyoming valleys, is well developed (Baird and Brett, 1983).
Above the Windom-Genesee contact there are approximately eleven feet of organic rich black shale, dark grey shale, and concretion-bearing horizons which comprise the lower part of the Genesee Formation. This sequence of largely anoxic and minimally dysoxic basinal facies is extremely condensed; at Ithaca, New York, the equivalent stratigraphic interval is in excess of 150 m (500 feet) (deWitt and Colton, 1978; Baird and Brett, 1986A). Fossils which can be collected from the basal three feet of the Cayuga Creek Geneseo section include current-aligned Styliolina, the brachiopod Devonochonetes, and scattered wood fragments.
At the highest falls, dark, organic-rich and conspicuously laminated beds of the Penn Yan Shale Member are abruptly overlain by the 20-25 cm (8 to 10 inch) thick ledge of the Genundewa Member and its associated 1-2.5 cm (0.5 to 1.0 inch) thick basal lag veneer of North Evans reworked pelmatozoan, conodont, and bone debris. Further east in Genesee County, this lag unit apparently disappears and the base of the Genundewa become conformable. Although the North Evans at this locality is a bit less conspicuous than it is at STOP 2, it still yields glauconite-coated reworked concretions and a great abundance of conodonts. As at STOP 2, the Genundewa is a dense, grainstone to packstone blanket accumulation of Styliolina shells. The grotesque Penn Yan concretionary bed below the North Evans contact is also developed at other adjacent sections; it may have formed as a geochemical response to the proximity of the North Evans erosion surface which was being scoured out from above.

SunB: STRATIGRAPHY, STRUCTURAL GEOLOGY, AND HYDROGEOLOGY OF THE LOCKPORT GROUP: NIAGARA FALLS AREA, NEW YORK
DOROTHY H. TEPPER
Water Resources Division
U.S. Geological Survey
Ithaca, New York 14850
WILLIAM M. GOODMAN
Department of Geological Sciences
University of Rochester
MICHAEL R. GROSS
Pennsylvania State University
University Park, PA. 16802
WILLIAM M. KAPPEL
RICHARD M. YAGER
The Niagara Falls area is known for its classic geology. An internationally recognized stratigraphic sequence of uppermost Ordovician and Silurian rocks is exposed along the walls of the Niagara Gorge. Summaries of the geology of this area are provided in Tesmer (1981) and Brett and Calkin (1987).
The purpose of this field trip is to provide an overview of some current research on the stratigraphy, structural geology, and hydrogeology of the Upper Silurian Lockport Group, which caps the section exposed in the Niagara Gorge. There has been much recent interest in the Lockport Group, particularly in the Niagara Falls area, where ground water within it has been contaminated by hazardous waste. In 1987 the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA), began a 4-year study of the hydrogeology of the Niagara region. The primary objective of this study is to define the regional ground-water flow system so that a three- dimensional ground-water flow model can be constructed that can provide a regional hydrogeologic framework for future site-specific research efforts.
The U.S. Geological Survey recognizes "Lower," "Middle" and "Upper" Silurian and designates the Lockport Group as Middle Silurian. However, in a New York State Geological Survey publication by Rickard (1975); the use of "Middle" Silurian was abandoned in New York and was replaced with the terms "Lower" and "Upper" Silurian to be consistent with European usage. The Lockport Group is designated as Upper Silurian by Rickard (1975) and will be referred to as such in this paper."

SunB: STRATIGRAPHY, STRUCTURAL GEOLOGY, AND HYDROGEOLOGY OF THE LOCKPORT GROUP: NIAGARA FALLS AREA, NEW YORK

STOP 1. Frontier Stone Quarry
The First stop will be at the Frontier Stone Quarry in the Town of Gasport, where we will examine the stratigraphy of the Gasport Limestone, the lowermost formation in the Lockport Group. This quarry is located along a reentrant on the Niagara Escarpment we we will also examine changes in joint orientations along this feature.

STOP 2. Niagara Stone Quarry
The second stop will be at the Niagara Stone Quarry in the Town of Niagara, where we will examine the Lockport Group stratigraphy from the base of the Gasport Limestone to the upper part of the Eramosa Dolomite (previously termed the "Oak Orchard Dolomite"). We will also discuss fractures and large-scale "pop-ups" on the quarry floor.

STOP 3. Electromagnetic and hydraulic test site
The final stop (also in the Town of Niagara) will be at a site where the USGS has conducted detailed electromagnetic surveys and hydraulic tests as part of the USGS/USEPA regional hydrogeologic study. This stop will include a demonstration of electromagnetic techniques, including terrain conductivity and VLF (very low frequency), and a discussion of downhole instrumentation and the cross-hole hydraulic testing program that has been conducted at the site.

SunC: PALEOECOLOGY AND SEDIMENTOLOGY OF MIDDLE DEVONIAN SHORT-TERM SEA-LEVEL FLUCTUATIONS RECORDED WITHIN THE WANAKAH SHALE MEMBER OF WESTERN NEW YORK
KETIH B. MILLER
Department of Earth Science
Clemson University
Clemson, South Carolina 29634
The fine-grained sediments of the Middle Devonian Hamilton Group, deposited within the northern tongue of the storm-dominated Appalachian Basin, have proven to be an excellent testing ground for many paleoecologic and stratigraphic concepts as demonstrated by many past NYSGA guidebook articles. The extensive stream and lake shore outcrop exposures, relatively undisturbed "layer cake" stratigraphy, and well-preserved benthic faunas of the Hamilton Group in western and central New York are ideal for detailed sedimentologic, paleontologic, and taphonomic studies. Such studies have begun to uncover the wealth of information contained within the superficially homogeneous mudrocks and thin limestones of the Hamilton Group.
Fossil taphonomy is an important, if not vital, source of data for the interpretation of depositional environments, particularly within fine-grained rocks lacking obvious sedimentary structures. The relative effects of the post-mortem processes of reorientation, disarticulation, fragmentation, corrasion and encrustation upon various skeletal materials yields considerable information on rates of burial, exposure time, and degree of physical reworking (Brett & Baird, 1986a). Comparison of these taphonomic features from bed to bed or outcrop to outcrop enables subtle environmental gradients to be discerned (Norris, 1986).
As attention has been drawn to the details of individual shell beds, their storm-event origins have increasingly been recognized in shallow shelf settings. Using individual storm event-beds as building blocks, a temporal hierarchy of physical processes and biological responses can be reconstructed, from the scale of single beds to the ordering of facies sequences within an entire depositional basin (Aigner, 1984, 1985). Internally, shell beds record the complex short-term interactions of episodic storm-generated physical disturbance, substrate consistency, and benthic community composition (Miller, et al., 1988). Onshore-offshore gradients in the relative frequency, sedimentologic character and fossil taphonomy of storm beds enables relative water depths to be determined (Brett et al., 1986a). In addition, widely traceable storm event-beds or packages of event beds possessing distinctive taphonomic and faunal signatures can be used as isochronous markers for very high-resolution correlation. At a yet greater temporal scale, cyclic patterns in the taphonomy and faunal composition of shell beds reflect sea-level fluctuations at several temporal scales (Savarese et al., 1986; Brett and Baird, 1986b; Miller, in press). These cycles afford a potentially valuable means for correlation since the positions of maximum regression and transgression provide basinwide isochronous markers. The character of these cycles also provides a very important clue to the dynamics of deposition within the northern Appalachian Basin during the Middle Devonian.

SunC: PALEOECOLOGY AND SEDIMENTOLOGY OF MIDDLE DEVONIAN SHORT-TERM SEA-LEVEL FLUCTUATIONS RECORDED WITHIN THE WANAKAH SHALE MEMBER OF WESTERN NEW YORK

STOP 1. Elevenmile Creek At Darien Lakes State Park
The streambank exposure along Elevenmile Creek within the Darien Lakes State Park is the type locality of the Darien Center Submember. The entire 4-meter stratigraphic interval is well exposed here, and the major key beds can be easily recognized at the outcrop. We will use this stop to become familiar with the distinctive character of each of the various key beds discussed in the text. This locality provides an excellent opportunity to closely examine the vertical sequence of shell bed types and fossil assemblages characteristic of the Darien Center Submember.
Figure 11 displays the presence/absence macrofaunal data for this locality. This data reveals a nearly symmetric pattern, interpreted as reflecting a regressive-transgressive eustatic sea level cycle. The higher faunal diversities of the transgressive half of the cycle probably reflect lower turbidity conditions, and are associated with more closely spaced and more condensed shell beds.
Near the center of the cyclic sequence is a prominent biostromal coral bed. Named the Darien Coral Bed, it attains its best development at this locality, and is dominated by the branching tabulate coral Eridophyllum. At Buffalo Creek (Stop 2) to the west, this same coral bed is represented only by widely scattered Heliophylum and Cystiphylloides corals. Along the outcrop belt to both the east and west of Elevenmile Creek, the Darien Coral Bed thins and becomes a horizon of scattered rugose corals before ceasing to be a recognizable marker bed (see Fig. 4 in the text).
NOTE: NO COLLECTING IS PERMITTED ON THE PROPERTY OF THE DARIEN LAKES STATE PARK.

STOP 2. Buffalo Creek At Girdle Road Bridge
A continuous cut bank on the south side of Buffalo Creek to the west of the Girdle Road bridge exposes the entire Darien Center Submember for a distance of over 500 meters. At this locality, the Darien Center cycle is only 3 meters thick and the transgressive half is highly condensed. The presence/absence faunal data of Figure 12 shows this asymmetry and also reveals the sudden diversity changes associated with traceable key beds. These distinctive marker horizons represent subcycle boundaries and are the basis for correlation across western and central New York State.
At the base of the Darien Center Submember is a peculiar discontinuity surface which is especially well displayed at this locality. This discontinuity is represented by the undulatory Stolle Road Bed which repeatedly separates from and merges with the underlying Mt. Vernon Bed defining a series of mudstone lenses of varying amplitude and width (see Figs. 8 and 9 in text). The mudstone lenses, or what I call "swells," are elongate features trending at a high angle to depositional strike. Dense shell layers dominated by the tiny brachiopod Ambocoelia occupy the broad flat "channel" areas between the swells. These shell layers extend up the flanks of the swells, becoming thinner and progressively losing fossil taxa. Over the tops of the swells the discontinuity is often represented only by a horizon of pyritic burrow tubes and pyrite nodules. The geometry of the swells and channels, and their approximately onshore-offshore orientation, suggest an analogy with modern sedimentary furrows produced by helical flow cells within episodically flowing bottom currents. This irregular erosion surface was formed during the early regressive phase of the Darien Center cycle, and may record an accentuated regressive pulse produced by a superimposed subcycle.

STOP 3. Lake Erie Shore North Of Eighteenmile Creek
After only a few hundred feet (before the bridge) turn right onto gravel drive and park in privately owned gravel parking area. Walk across the bridge over Eighteenrmle Creek and then proceed toward the lake shore along the north bank. At the mouth of the creek walk north along the lake shore
This beautiful cliff exposure provides access to the upper transgressive half of the Darien Center Submember which alone is about 3 meters thick. The lower portion of the section is below lake level at this locality. The closely spaced shell beds can be easily examined and sampled here, and fossil collecting is excellent. Figure 13 shows the presence/absence faunal data for these lake shore cliffs.
The major key beds are easily recognized here. Especially well displayed at and near the lake level are the Lakeview Bed and the underlying shell beds containing abundant Pleurodictyum corals. Exposed bedding plane surfaces of these beds reveal well preserved in situ fossil assemblages on shell bed tops. Articulated and life position brachiopods are abundant, and complete trilobites and camerate crinoids can often be found. These fossils represent smothered epifaunal communities which had colonized winnowed shell hash layers. The shales overlying the shell beds are nearly barren of fossils and probably represent muds rapidly deposited by storm events. These muds were likely responsible for the preservation of the underlying shell beds by removing them from the sediment/water interface where taphonomic loss is great, and by stimulating early diagenetic pyritization and carbonate concretion formation.

SunD: (continuation of) EURYPTERID BIOFACIES OF THE SILURIAN-DEVONIAN EVAPORITE SEQUENCE: NIAGARA PENINSULA, ONTARIO, CANADA AND NEW YORK
Samuel J. Ciurca, Jr.
For the past 28 years, I have been studying eurypterids, their stratigraphic occurrence, distribution, and associated flora and fauna, particularly in northeastern United States and Ontario, Canada. In New York the best known eurypterid assemblages are: 1) the Eurypterus remipes Fauna of the Fiddlers Green Formation that includes the earliest discovery of an eurypterid on this planet (by Dr. Mitchell in 1818); 2) the younger Eurypterus lacustris Fauna of the Williamsville Formation of western New York and Ontario, Canada; and 3) the eurypterid fauna of the Shawangunk Formation southeastern New York.
The search for new eurypterid faunas and the study of their geographic distribution in the Siluro-Devonian rocks of the region is important for several reasons. Foremost is the fact that the eurypterid faunas are punctuated within the known stratigraphic sequences. New genera appear suddenly within the sequences, e.g. Waeringopterus Zone, Erieopterus Zone, etc. When an eurypterid species disappears from the record completely, it is easily understood and we often assume extinction. The sudden appearance (or ecological replacement) of a species by an unrelated forms, (such as the Silurian Eurypterus being replaced by Erieopterus in the Early Devonian, is much more difficult to decipher. Only continued search for intervening occurrences, stratigraphically and geographically, will provide the data needed to understand the evolution of the eurypterids and their assemblages.
A second factor of significance concerns the eurypterid assemblages. Generally, where eurypterids are found there is a conspicuous absence of other fossils, in number and especially in diversity. Hence, the stratigraphic sequence is often considered to be unfossiliferous. The evaporite-bearing Salina Group is notable of this designation. Precise correlation, regionally and inter-regionally is needed to achieve a more complete understanding of these unique invertebrates. See Figure 1 for a map showing areas having exposures of Late Silurian-Early Devonian strata.

SunD: (continuation of) EURYPTERID BIOFACIES OF THE SILURIAN-DEVONIAN EVAPORITE SEQUENCE: NIAGARA PENINSULA, ONTARIO, CANADA AND NEW YORK

STOP 1. Section high in Lockport Group
("Oak Orchard" of Zenger). Large stromatolite mounds.

STOP 2. Ellicott Creek Breccia
Type Sections: Ellicott Creek Breccia, Williamsville Waterlime.
Figure below shows stratigraphic section of part of Bertie Group.

View from escarpment on left-WHEW!

STOP 3. Fiddlers Green Fm. Etc
Inactive quarry exposing a portion of Fiddlers Green Fm. up through Cobleskill Fm. Large quarry in Onondaga Limestone just to the east.

STOP 4. Indian Falls-Falcon Crest
Falls consists of massive Victor Dolostone - lush green algal mats still thrive on bedding planes, in pools and channels. No eurypterids have been seen.

Neat boulder on left

Genesee LeRoy Stone Quarry on Right

STOP 5. Stratigraphic section
Stratigraphic section showing Camillus Shale (Salina Group) and overlying Fort Hill Waterlime.

STOP 6.

Dolomite Products Co., Inc. LeRoy Plant.
Old locomotive ensemble, quarries in Onondaga.

STOP 7.

Erratics of Victor Dolostone
Note Whitfieldella brachiopods littering bedding planes.

STOP 8. Neid Road Quarry (Ciurca, 1973).
Bertie Group and overlying Onondaga Limestone exposed here.

STOP 9. TURN RIGHT into Oatka Park.
Exposures of Syracuse Fm. (Salina Group) along Oatka Creek. Ruins of buildings-old gypsum mines.

SunE: SHALLOW WATER REEFS OF THE MIDDLE DEVONIAN EDGECLIFF MEMBER OF THE ONONDAGA LIMESTONE, PORT COLBORNE, ONTARIO, CANADA
THOMAS H. WOLOSZ
Center for Earth & Environmental Science
SUNY College at Plattsburgh
Plattsburgh, N.Y. 12901
The reefs of the Edgecliff member of the Onondaga Formation are a well known part of the geology of New York State and the Niagara Peninsula in Ontario, Canada. Over the past thirty to forty years, the Onondaga and its reefs have been the subject of a number of Master's theses and Doctoral dissertations (see Wolosz, 1984, for references), and yet there are still a large number of unanswered questions regarding these reefs and the Onondaga in general.
The Edgecliff has generally been assumed to represent a warm, tropical, shallow water environment due to its abundant and diverse coral fauna. However, the lack of stromatoporoids and calcareous algae is a notably unusual feature for Devonian reefal limestones. The absence of these organisms led Kissling and his students (Kissling, 1987; Kissling and Coughlin, 1979; Cassa and Kissling, 1982) to interpret these reefs as deep water structures. They have also pointed to the absence of peritidal facies in the Onondaga as added support for this interpretation, suggesting that the preserved Onondaga represents a deep water facies, the shallow water facies which rimmed the basin having been removed by erosion.
Studies of other Edgecliff reefs have yielded results which do not support this interpretation. The Thompson's Lake bioherm has been interpreted as having grown into the surf zone (Williams, 1980), while the LeRoy Bioherm has been interpreted as a shallow water deposit by Poore (1969), Lindemann (1988), and Wolosz (1988). Wolosz (1984, 1985) presented evidence of coral breakage and overturning to argue for shallow water conditions during reef growth at Roberts Hill and Albrights Reefs.
This field trip will examine the Ridgemount and Quarry Road bioherms, which are being interpreted by the author as the shallowest water reefs known from the Onondaga.

SunE: SHALLOW WATER REEFS OF THE MIDDLE DEVONIAN EDGECLIFF MEMBER OF THE ONONDAGA LIMESTONE, PORT COLBORNE, ONTARIO, CANADA

STOP 1. Ridgemount Bioherm
HARD HATS REQUIRED Please beware of overhangs and loose rock. NOTE: Visitors should sign in at the quarry office 0.8 miles to the north.
Figure 4A is a map of the Ridgemount Quarry. Note that reef facies are restricted to the northeastern quarter of the quarry. The north wall of the quarry exposes a number of bioherms (Satellite bioherms), while a single bioherm can be examined in the east wall, just north of the water filled section of the quarry (Bioherm A). The northeast wall of the quarry displays abundant coral in a bed which pinches and swells from about 0.7 to roughly 2 meters thick (Coral Beds).
Cassa and Kissling (1982) interpreted the Edgecliff in this quarry as consisting of numerous small bioherms, which is, to a large degree, correct. However, it is important to note the dip of the beds which overlie this coral bed (in particular the quarry walls surrounding tank cars on Upper Level). These exposures are above and to the east of the Coral bed exposure, but they are already dipping westwards, indicating that these small mounds existed behind a larger structure to the east. While the dip has to some degree been enhanced by compaction (especially around Bioherm A), a pinch out of these beds can be observed along the north wall of the quarry, indicating a primary depositional dip. Further, examination of the beds behind the tank cars reveals numerous thickets of Acinophyllum and small branching tabulate corals. These thickets have not been observed elsewhere in this quarry, suggesting colonization of a topographic high on the sea-floor. Finally, note the top of the quarry wall (good exposures may be found along the quarry rim above the tank cars, also above Bioherm A) which consists of a clean biostromal sand containing large phaceloid rugosan colonies (Cyathocylindrium?) and abundant solitary rugosans and favositids. This facies appears to be restricted to the general vicinity of the stratigraphically lower coral buildups, also supporting the presence of a topographic high on the sea-floor.
Examination of the coral buildups (Bioherm A, satellite bioherms, coral beds) reveals little internal structure. Unlike the well developed rugosan thickets commonly found in thicket/bank structures or the dense growth of colonial corals within mound structures (as will be seen at the Quarry Road bioherms), these buildups are most commonly characterized by debris and· overturned and broken coral colonies (large overturned favositids are especially notable). Bioherm A (Figure 5) is easily accessible for examination. Note the absence of a well developed core facies in this structure. This unusual lack of internal structure is interpreted as indicative of very shallow water conditions during mound development. Intermittent high energy periods (storms) prevented the continuous coral development seen elsewhere in the Edgecliff, and resulted in the debris-mound facies seen in this quarry.
A proposed model of the coral mounds and beds present in the Ridgemount Quarry is presented, in Figure 48. In this model, initial colonization of the shallow sea-floor lead to the development of small debris mounds (little in-place growth is preserved due to the battering of these mounds by waves). These debris mounds acted as sites for further colonization by rugosans, and as protection for tabulate corals colonizing the sea-floor to the lee of these mounds. Gaps between mounds would fill with storm generated debris, and then be recolonized by coral, eventually leading to the formation of an elongate "Coral Ridge", with small satellite bioherms in a back-ridge biostrome.
No other Edgecliff reef exposure exhibits such extensive evidence of storm damage, suggesting a shallower water depth than any other known structure. Further, evidence of the early growth of this structure following transgression over the exposed Bois Blanc (and therefore shallow water conditions) can be seen along the north wall of the quarry, to the west of the last satellite bioherm. There, the carbonate sand facies extending from the satellite bioherm interfingers with the basal "Springvale Sand", indicating that the growth of the satellite mound was coeval with the deposition of the "Springvale" only a few meters to the west.
Ancillary Topics at Stop 1. The west wall of the quarry exposes the Siluro-Devonian disconformity described by Kobluk, et al. (1977). This contact is characterized by borings which have been filled by quartz sand and glauconite. The underlying Silurian dolomite contains brecciated horizons. Excellent samples are available for class use. Finally, possible teepee structures are present in the Bois Blanc just below the contact with the Onondaga (see map Figure 4A).

Stop 2. Quarry Road Bioherm
The West Quarry (Figure 6A) offers examples of two types of Edgecliff Reefs. Along the north wall two small, mono-generic mounds and some quarried blocks of mound facies are available for examination. The easternmost mound (and the bioherm blocks) consist of Acinophyllum colonies, while the western mound is predominantly Syringopora. Unlike the bioherms at Ridgemount these small structures exhibit dense, in-place growth of colonial coral.
At the south end of the quarry, exposed on a glaciated surface, are three small thicket/bank structures (Figure 68) the largest of which is approximately 26 meters in diameter. These small mounds are made up of thickets of phaceloid colonial rugosans interbedded with biostromal beds of small branching tabulate corals. Again, compare the in-place preservation of coral in these small structures to the debris mounds at the Ridgemount Quarry, keeping in mind that we are now roughly 3 kilometers down depositional dip from the Ridgemount structures. Also note that these structures are quite small when compared to other thicket/bank reefs such as the roughly 245 meters diameter North Coxsackie Reef south of Albany and the approximately 300 meters diameter Buffalo Country Club Reef (bioherm #'s 3 and 28 of Oliver, 1976).
Finally, examine the grainstone bed along the northeast and east wall of the West Quarry. Stromatoporoids have become quite abundant in this facies, and can also be occasionally found in the underlying, muddy Cystiphylloides biostrome.
Ancillary Topics at Stop 2. The Bois Blanc Formation floors both the East and West Quarries. Fossil collecting is excellent, with the quarry floor littered with loose rugosans, tabulate corals, and other fossils.

SunF: A FRESH LOOK AT THE SEDIMENTS WITHIN THE TERRACES AND CLIFFS THAT PARALLEL THE LAKE ERIE SHORE IN ERIE COUNTY, PENNSYLVANIA
DAVID THOMAS and RAYMOND BUYCE
(Mercyhurst College)
The lake plain adjoining the coastal bluffs of Lake Erie in Pennsylvania is comprised of two to three major southwest-northeast trending terrace systems. They form a stair-step arrangement of very gently sloping. terraces each bounded on the north by slightly to precipitously steeper escarpments or cliffs. The edges of these terraces have been referred to as "beach ridges"by several early workers (e.g. Leverett, 1892). Extensions of the terrace margins in Ohio and elsewhere are actually ridge-like although their beach origin has been questioned. Each relatively flat terrace level is reliably attributed to deposition associated with a corresponding lake level of a Pleistocene precursor to Lake Erie. It is still an open question whether the environment of deposition for any particular terrace or part thereof can be justifiably ascribed to beach deposition or whether a braid-plain (saridar), delta, or some other setting might have been responsible. Some of the early work relied heavily upon topographic expression to seek answers to the questions of origin but on this trip we will have the opportunity to look at two fine exposures within the terraces to see if the sedimentological evidence is more definitive.
Exposed in the gravel pit at the first stop is the uppermost of the two terraces present along the southeastern part of the Harborcreek 7 1/2 minute quadrangle. The upper terrace is attributed to sediment deposition associated with Lake Whittlesey (elevation: 740 feet, age: 13,000 yr B.P.). Our second stop is on the shore of the modern Lake Erie where the upper approximately 70 feet of bluff exposes the sands and gravels which underlie the lowermost of the two terraces. These sediments are ascribed to deposition associated with Lake Warren which was both lower and later (elevation: 675. age: 12,000-13,000 yrs B.P.) Also exposed underlying the sands and gravels in the bluff at this location is more than 100 feet of glacial till (periglacial? diamict). To enable you to better orient yourself geologically a brief description of the geology of the field trip area is provided below.

SunF: A FRESH LOOK AT THE SEDIMENTS WITHIN THE TERRACES AND CLIFFS THAT PARALLEL THE LAKE ERIE SHORE IN ERIE COUNTY, PENNSYLVANIA

We will cross Seven-Mile creek
We will cross Seven-Mile creek, an essentially north-flowing creek that empties into Lake Erie. Seven-Mile refers to the distance of the creek and the city of Erie to the west, and not the length of the creek.

You will be traveling across the Ashtabula Morainic System.
The Girard and Ashtabula Moraines which are easily distinguished south of Erie, PA cannot be recognized at the two separate ridges east of Erie, Ashtabula till Halburn, PA.

Overlook.
Ahead is the steeply descending North-facing slope of the Ashtabula Moraine and the flatter lying terraces of lakes Whittlesey, Warren I-II and Warren III.

We continue to descend the north-facing slope of the Ashtabula ice marginal moraine.

North facing slope of the Ashtabula Ice Marginal Moraine.
We will be traveling east on and parallel to the north facing slope of the Ashtabula Ice Marginal Moraine.

We will be descending a much gentler north slope of the Ashtabula Moraine.

We'll remain on Ashtabula deposits.

We cross a west-flowing tributary of Twelve-mile creek.
The stream has cut into stratified, subangular to subrounded cobbles with an occasional glacial erratic. The material has not been extensively worked.

We will descend a relic "wave cut" cliff of Lake Whittlesey
We will descend a relic "wave cut" cliff of Lake Whittlesey and proceed north across much flatter terrain. The terrain is underlain by gravel of a variety of sizes.

To our right (north) is the lake Warren I terrace.

The cemetery to our left illustrates the true topography.
Large amounts of gravel have been quarried from both sides of the cemetery.

STOP 1. Central Sand And Gravel Pit
(Stop description by: Charles Carter, Univ. of Akron from Thomas and others, 1987)
Introduction
This pit is part of an extensive (several kilometers long and up to a few kilometers wide) sand and gravel deposit that trends southwest-northeast, roughly parallel to the present Lake Erie shore (Figure 14). The existing pit is nearly mined out as are adjacent pits to the west and south. The sand and gravel are used for road construction, the mining is done with front-end loaders, and the processing is accomplished by a hydraulic sorter. The deposit is at least 8 m (26 ft) thick and mining has been done to 5 or 6 m (16 or 20 ft) below the original, prestripped surface. Foreman Scott Wassink said that the deposit was coarser to the east so that although the sediments exposed along the western face are largely granule- and pebble-sized, the overall grain size for the pit was larger.
A small, about 4 m (13 ft) long, normal, nearly bedding-plane parallel fault occurs near the center of the face. The apparent fault plane is curved and has a strike of about east-west and an overall dip of about 23 N although siltstone cobbles are oriented nearly 90° from the horizontal at the north end. Whether the origin of the fault is tectonic or isostatic is unknown.
The elevation of the surface of this deposit (about 780 to 790 ft), and the correlation of this surface both to the east and the west, has led to the mapping of this feature and elevation as the Whittlesey strandline (Schooler, 1974, p. 11, 12). The deposits underlying this surface in this area of Pennsylvania have been interpreted as "beach deposits" (most recently by Schooler, 1974, p. 19) mainly on the basis of geomorphic evidence. However, she also recognized a "channel-like feature" at one location that included imbricated gravel that she interpreted as a "delta" (p.22). Schooler's work is typical of most of the work that has been done on the "beach ridges," in that the interpretations of these deposits have been made largely on topographic expression and texture with little consideration given to the internal characteristics and geometry of the deposits. Because of this, University of Akron students and faculty are doing sedimentologic studies of the ridges in order to improve our knowledge of their origin and evolution.
Sedimentology and Paleogeography
The pit lies near the western apex of a triangular-shaped terrace that opens to the east (Figure 15). A north-south face with a length of about 350 m (1148 ft) and a mean height of about 4 m (13 ft) provides an excellent cross section of the deposit. There are three facies exposed in the face: an interbedded granule and pebble/cobble facies (about 80 percent of the face), a gravel lens facies (5 percent), and a turbated clay/gravel facies (15 percent) (Figure 16).
The interbedded granule and pebble/ cobble facies consists of thin to thick beds and lenses that dip gently to the north. The particles making up the individual beds or lenses consist almost entirely of well sorted, well rounded, disc-shaped, siltstone clasts. The individual beds and lenses of granule contain laminations and very thin beds that parallel the enclosing bedding planes. The laminations and beds are distinguished on the basis of slight textural differences, although internally they appear to lack grading.
The individual lenses of pebble/cobble consist of framework-supported clasts with long axes oriented parallel to the northerly dip of the surrounding beds. The majority of the lenses are made up of siltstone pebbles no more than a few centimeters thick and thin to single pebble thicknesses at the margins.
In general, the beds and lenses can be traced laterally for 10 to 20 m (33 to 66ft). The granule beds are thickest and most continuous, but the pebble/cobble lenses are up to 25 m (82 ft) and 20 cm (0.6 ft) thick. In places, the pebble/cobble lenses truncate the underlying granule at low angles. Overall, there is little if any lateral change in this facies from north to south, but vertically the facies fine upward in a 2-3 m (6-10 ft) section from fine pebbles to granules. The true dips of the sloping surfaces in both the granule and the pebble/cobble lenses are oriented between 305° (NW) and 15° (NE) with dips from 4° and 17° (the dips of 6 of the 7 readings lie between 4° and 7°). The dip orientations are not scattered. The 2 lowermost orientations are just east of north whereas the 5 uppermost orientations are to the northwest.
The gravel lens facies consists of flat to convex-up lenses that enclose cross-stratified beds of granules, pebbles, and cobbles In this facies, some of the long axes of the gravels lie parallel to the stratification and others do not. In two flat-topped lenses near the south end of the face, the shape of the cross-stratification resembles lateral accretion surfaces. In a major convex-up lens located about one-third the distance from the southern end of the face, the central part of the lens consists of tightly packed, imbricated gravels. Flanking the central zone are cross-stratified cobbles, pebbles, and granules that fine as well as steepen (11° to 27°) away from the center. There is no apparent change in the texture of the individual cross-stratified layers. A second, much smaller but coarser (mostly cobbles), convex-up lens lies about 30 cm (1 ft) above the larger lens. This lens lacks the cross-stratification of the underlying lens. In both lenses the siltstone cobbles dip uniformly in a westerly direction whereas the stratification flanking the major lens dips to the south.
The gravel-size clasts, as in the interbedded facies, are framework supported, although in both facies there are numerous discrete cobble and even siltstone boulders that occur here and there in the section, parallel to the stratification of the enclosing granules, and commonly in the same planes. The pebbles and cobbles in the lenses are mostly siltstone. However, at three scattered places, well sorted and rounded, more spherically-shaped, gravel-sized clasts of mixed rock types are found. A pebble count of 69 clasts from one of these gravel lenses showed the following: 53 percent siltstone, 23 percent sandstone, 20 percent igneous and metamorphic, and 4 percent carbonate clasts.
The gravel lenses can be traced laterally for 10 m (33 ft) or more with the major convex-up lens having a lateral extent of at least 30 m (98 ft). The lenses dip gently to the north and although there are no vertical changes in the lenses, nearly all of the lenses show an up-dip (south) decrease in grain size. The true dip orientations of the "cross-stratification" in the lenses lie between 160° (SE) and 190° (SW) with dips from 11° to 27°. The true dip orientation of the cobbles in one imbricated zone is 275° (NW) with a dip of 10°, and the unmeasured orientation of other imbricated zones is also to the west.
The turbated clay/gravel facies consists of pods of clay separated by contorted zones of granule/gravel. Most of the facies has been removed, but before the surface was stripped there was about 15 cm (0.5 ft) of soil underlain by about 75 cm (2.5 ft) of clay (Scott Wassink, personal communication).
In terms of facies association and order, the interbedded granule and pebble/cobble facies is eroded by the gravel lens facies, with a relief as much as 1 m (3 ft). There are about 6 gravel lenses along the face with the lenses occurring throughout the section in a vertical sense, and along the southern two-thirds of the face. The turbated clay/gravel facies caps the two underlying facies.
Interpretation
The northward-dipping, interbedded granule and pebble/cobble facies is interpreted as proximal Gilbert-type deltaic foresets. The gently dipping lenses represent deposition from grain flow and avalanching on the delta foreset because of flow expansion and deceleration at the river mouth. The coarser gravel lenses may have been segregated during avalanching and/or may represent higher energy, episodic events. Rapid deposition took place during homopycnal flow mixing (Nemec and Steel, 1984). The incomplete foreset thickness of .3 to 4 m ( 10 to 13 ft) indicate minimum water depths of 3 to 4 m (10 to 13 ft) at the river mouth. The overall fining-upward sequence in these deposits may be due to decreased flow strengths caused by a gentler gradient.
The cross-cutting, cross-stratified sands are interpreted as channel deposits. Incisions of the delta slope by distributary channels during episodic drops in water level, and subsequent rises in water level, may have caused this scour and fill type of structure.
The northerly paleoflows are consistent with a delta/coastal alluvial fan origin. Northward flowing streams coming off the steep isostatically uplifted glaciated uplands debouched into glacial Lake Whittlesey with little modification by waves. The high rate of bedload coupled with low wave energy allowed the deltas to build directly to the north.
Alternate hypotheses could include sandbar or barrier systems. However, the geometry of the deposit and the thickness and lateral extent of the interbedded granule and pebble/cobble facies make these hypotheses unlikely.

We will descend a short, steep slope onto an area of relatively low relief.
The elevation along Route 20 is about 780 feet. This is the edge of the Law-Whittlesey Terrace. The elevation at the bottom of the steep slope is 760 feet. This is the general elevation of the Lake Warren I-II level in the eastern section of Erie county. The slope is thought to be a relic wave cut cliff cut by the waves of Lake Warren I and can be seen running parallel to US Route 20 about 40 feet above it.

Cross a channeled west flowing tributary stream to Twelve-mile Creek.

We continue to cross the lake warren I Terrace.

STOP 2. Brickyard Road Section.
(Description by: Dave Thomas and Ray Buyce from Thomas and others, 1987)
This stop is located at the foot of a private, unpaved road that extends north of US Route 5 from Brickyard Road in the northeast section of the Harborcreek, PA 7.5-minute quadrangle (Figure 14). The property is owned by the McCord family, one of the pioneer vintners in the Pennsylvania-New York section of the grape belt. Permission must be obtained from the McCord family for access to the property. We will be examining the bluff-face exposures.
The summit of the bluff overlooking Lake Erie about 300 (1000 ft) from US Route 5 is dangerous! It is capped by non-cohesive sand that fails under very small additional loads.
DO NOT WALK TO THE BLUFF EDGE!
Landform
The summit of the bluff at this location is about elevation 700 feet. It is the location of the northern margin of a gently sloping terrace that can be traced south on Brickyard Road from elevation 730 feet at us Route 5 to elevation 770 feet just below US Route 20. We believe that this terrace represents a Lake Warren I level.
Stratigraphy
General. Wave erosion and a variety of mass wasting processes have exposed approximately 50 m (165 ft) of glaciogenic deposits represented by 2 distinct facies. The lower part of the section is a diamict facies which comprises 17.4 m (57 ft) or 35 percent of the total bluff height. The upper 33 m (108 ft) or 65 percent of the total bluff height is composed of a gravel and sand facies. Figure 16 presents a graphic display and Table 1 the detailed stratigraphic description of the measured section.
Diamict Facies. This facies may be divided into 2 distinct lithologic types based upon thickness and grain size distribution. The lower segment consists of 11 units (1 through 11, Measured Section) ranging in thickness from 0.06 m (0.2 ft) to 0.6 m (1.75 ft). These 11 units occur as 2 different lithologies. Six of the units are massive, matrix-supported diamicts composed of olive gray, clayey silt to very fine sand supporting angular to subrounded pebbles and rarer gray and reddish gray soft clay clasts. Thicknesses range from 0.07 to 0.53 m (0.25 to 1.75 ft). The other 5 units are laminar-bedded, clayey silt, silt, or very fine sand supporting angular to subrounded pebbles and rarer gray and reddish gray soft pebble-size clay clasts. The thicknesses range from 0.06 to 0.07 m (0.20 to 0.25 ft). These 2 lithologies consistently alternate up through the entire 2.2 m (7.25 ft) of this segment of diamicts. At the lower contact of the uppermost unit (11) are alternating dark and light gray, clayey silt laminae with a roll-up structure and folds overturned westward.
The upper diamict segment is 12.75 m (41.85 ft) thick and consist of 4 units (12 through 15) ranging in thickness from 1.3 to 5.3 m (4.25 to 17.25 ft). These 4 units are composed of olive gray, massive, clayey silt or very fine sand matrixes supporting angular to subrounded pebbles, and fewer cobbles and rare boulders. The angular cobbles are hard siltstones or very fine sandstones whose origins may be found in the Upper Devonian bedrock to the immediate east. The subangular to subrounded cobbles are either Lower Paleozoic sedimentary rocks plucked from the Ontario-Erie basin farther to the east or Precambrian crystalline igneous and metamorphic rocks transported from the Canadian Shield. The lower 2 units (12 and 13) show, at their lower contacts, roll-up structures and folds in laminar clayey silt beds that are overturned toward the west. In addition, there is a normal fault with 6 mm (0.25 in.) displacement in the rolled-up laminar beds near the base of Unit 12.
Gravel/Sand Facies. The diamict and gravel/sand facies is separated by a 0.15 m (0.5 ft) thick laminar-bedded clay with a thin sand bed at the base and top. The contact between the clay and gravel facies appears erosional. The gravel segment of the gravel/sand facies (Unit 17) is 6.6 m (21.65 ft) thick. It consists of angular to subrounded pebbles and interstitial sand and clayey silt. The lower part of the unit has 2 cut and fill channels. The beds of the lowest channel dip northwest, while the beds of the upper channel truncate those of the lower and dip northeast. Bedding is not apparent in the remaining upper part of the gravelly unit; however, discontinuous fine-grain drapes occur throughout. A continuous 2.5 to 5 cm (1 to 2 in.) drape separates the gravel from the sandy units above.
The sandy segment of the gravel/sand facies is about 20 m (66 ft) to the summit of the bluff. The upper 4.6 to 6 m (15 to 20 ft) were not measured because of steepness and instability of the slope. The sand units are composed of very fine, fine, and medium sand with relatively thin interlayers of clayey silt or very fine sand. The clayey silts or very fine sands occur as drapes.
The lowest unit (18) is composed of 0.46 m (1.5 ft) of very fine laminated sand displaying horizontal, trough, wavy, and flaser bedding and beds of horizontally laminated clayey silt.
The overlying unit (19) is 10.6 m (35 ft) thick. The lower 7 m (23 ft) is covered with sandy colluvium; however, exposures east and west of the Measured Section indicate lithologies consistent with the measured upper 3.7 m (12 ft) of the unit. The upper 3.7 m (12 ft) is composed of alternating beds of very fine sand and clayey silt beds. The laminar clayey silts are bedded horizontally while the very fine sand units display horizontal, trough, wavy, and flaser bedding. Pebble-size drop stones are sparsely scattered through the unit. The thicker sand beds in the lower part of the unit yield to clayey silt beds upward through the unit. This fining upward sequence is contorted by soft sediment deformation structures with amplitudes of 3 ft or more in its upper part. The remainder of the measured section (Unit 20) which is 20.1 m (66 ft) thick is composed of sand and clayey silt or very fine sand beds. The sand beds display laminar and thin horizontal, wavy, trough, and flaser bedding and climbing ripples. The clayey silt or very fine sand occurs as relatively thin drapes.
QUESTIONS
Questions to be asked at this stop are basically the same as those at stop 2:
1. What process(es) formed the diamicts?
2. Is there evidence of sublacustrine deposition and if so what mechanisms were involved?
3. Is there more than one age of diamict here? What approach could be utilized to resolve the problem?
4. How many different environments of deposition may be represented by these sediments?

We will be traveling across the Warren I-II Terrace
We will be traveling across the Warren I-II Terrace from elevation 740 feet to elevation 760 feet over the next 1.8 miles, a gradient of about 11 feet per mile.

Edge of Lake Whittlesey Terrace, just above the Warren I scarp (Wave cut?).
US Route 20 is straight ahead (south) running along the edge of Lake Whittlesey Terrace, just above the Warren I scarp (Wave cut?).

Lake Whittlesey Terrace with the Warren I-II Terrace to our left.
We are now traveling on the Lake Whittlesey Terrace with the Warren I-II Terrace to our left.

SunG: PADDLING UP A MELTWATER CHANNEL: A LATE-WISCONSINAN ICE-MARGINAL CRUISE NEAR FREDONIA, NEW YORK
Randy J. Woodbury and Michael D. Jensen
Fredonia, N.Y. 14063.
Although the area near Fredonia was glaciated several times during the Pleistocene (see, for example: Leverett, 1902; Fairchild, 1907; Muller, 1963, 1977; Muller and Fahnestock, 1974; Schooler, 1974; and Cadwell, 1988), it was the most recent Late Wisconsinan ice margins, active here between 14,000 and 12,000 years B.P. (Calkin and Feenstra, 1985), that left, some of the more dramatic erosional and depositional marks on the landscape.
Staying within eight miles of the college and on the Lake Erie side of the nearby St. Lawrence - Mississippi continental divide, this trip will climb the hydraulic gradient of a glacial meltwater system that incised deep channels through Devonian bedrock, depositing sediment as deltaic gravels and lake clays.
We will begin at beaches of two of the large ancestral pro-glacial lakes of the Erie basin that are locally 170 feet and 240 feet, respectively, above the water level of present Lake Erie. The trip will ascend another 300 feet, then another 100 feet, as we follow a sub-marginal meltwater channel to the levels of two smaller lakes that were impounded along the ice margin.
Stops 1, 2, and 7, on the map below, will allow hands-on inspection of glacially derived gravels, and stop 6 will be in lake clay. The rest of the stops will be to view a channel that is now relatively dry, but would have been actively carrying meltwater during one or more glacial phases. The diagrams on the next two pages offer background on local glacial history and a schematic view of the subject channel.

SunG: PADDLING UP A MELTWATER CHANNEL: A LATE-WISCONSINAN ICE-MARGINAL CRUISE NEAR FREDONIA, NEW YORK

Passing over Canadaway Creek.
This valley formed embayments for proglacial Lake Whittlesey and Lakes Warren.

US Route 20 follows the Lake Warren strandline
US Route 20 follows the Lake Warren strandline from Central Ohio into Western New York. Gravel pits close to the highway provide an abundant source of aggregate for the highway.

View of the Escarpment to the left of the highway.
There are no resistant units to account for the formation of this cuesta. Abundant grape vineyards are growing in the well drained sands and gravels of Lakes Warren and Whittlesey beach deposits to the south.

A cemetery to the left.
There are many cemeteries located in the well drained deposits because they can be dug in almost year round.

STOP 1. Gravel Pit In Lakes Warren Beach Deposits.
This gravel pit displays typical deposits of a Lake Warren shoreline. U.S. Route 20 is constructed primarily of this material and follows the beach ridge for several hundred miles from northern Ohio to Batavia, New York. Lake Warren deposits are typically cross-bedded, well-washed sands and gravels. They were deposited within the high energy beach environment associated with each Lake Warren shoreline. The northward dipping beach face is well exposed on the western and eastern pit walls.
Lake Warren deposits differ from the corresponding Lake Whittlesey deposits which lie further to the south and about 70 feet higher in elevation on the lake plain (found along the ridge through Webster Road Cemetery on the map at left). Lake Warren deposits are generally finer grained and better washed than typical Lake Whittlesey deposits. This may have been a function of higher wave energy and/or a longer occupation of the Warren beach.
Notice the swallow nests bored into the firm silt deposits near the upper wall of the pit.
The beach of Lake Warren is the youngest glacial feature we will visit today, with Lake Whittlesey about 500 years older, and our subject meltwater channel (seen as Little Canadaway Creek on the map) older still.

Southern wall of an abandoned gravel pit.
To the south the apparent wave cut terrace just north of Webster Road is the southern wall of an abandoned gravel pit.

The Brocton Arch.
Prior to World War 2 several of the villages in Chautauqua County had similar arches in their villages. However, all of the villages but Brocton removed theirs to provide scrap metal for the war effort.

Webster road follows the Lake Whittlesey Strandline
Webster road follows the Lake Whittlesey Strandline for several miles from the Town of Portland east through the town of Pomfret.

STOP 2. Gravel Pit In Lake Whittlesey Beach Deposits.
This is one of two gravel pits near Portland that were recently opened for construction of a State prison in Brocton. While the elevation and nature of the gravel correspond to a Lake Whittlesey shoreline, the original deposition may have been into an earlier lake. Notice on the map that the 800-foot contour outlines a possible relic spit, formed by wave currents moving sediment easterly from the area near Cemetery Road at Webster Road.
The gravel here is widespread, forming a wide plateau between Webster Road and Ellicott Road. Much of the sediment is locally-derived, with large clasts of siltstone, apparently from Devonian strata higher in the escarpment to the south and east. The feature we are in has been recognized as a delta by Fairchild (1907), who considered that the sediment might be primarily rock excavated from the meltwater channel to the east and northeast. The southerly wall of this channel can be seen on the map as the ridge where Ellicott Road meets Highland Avenue.

To the north notice the fine surficial expression of the meltwater channel.

Notice the gas well just off to the north of Ellicott Road.
Gas wells are very common throughout Western NewYork. They are drilled primarily into the highly productive sandstones of the Silurian Medina Group which dip gently towards the southwest at approximately 50 ft/mi.

STOP 3. Overview Of The Meltwater Channel.
Stop 3 is an overview of channel morphology; envision a river of meltwater raging through the now-dry valley.

Passing through the channel
Passing through the channel towards the Lake Whittlesey strandline at Webster Road.

Webster road is still following the ancestral shoreline of Lake Whittlesey.

The southern wall of the abandoned gravel pit
The southern wall of the abandoned gravel pit mentioned previously within this roadlog is just left (north) of the road.

Passing over a buried channel indicated by seismic profiles and core samples.

Dropping into the channel
Dropping into the channel and passing over the misfit Little Canadaway Creek which currently occupies the meltwater channel.

Passing up the south wall of the meltwater channel.

STOP 4. A Walk Into The Ancestral Meltwater Channel
Plus A Visit To One Of Its "Hanging" Tributaries.
Stop 4 takes us to the channel's intersection with Chautauqua Road, where a drift-filled valley running northwesterly has been proposed in the area circled (Woodbury and Lash, 1985, abstract is inset on facing page). The natural gentle slope over the buried valley provided the least treacherous route for early settlers to cross the deep meltwater channel; Chautauqua Road is one of the county's oldest roads, commissioned by the Holland Land Company in the very early 1800s to connect Fredonia (then known as Canadaway) with the county seat in Mayville. At STOP 4 we will visit one of several 40-foot waterfalls that are characteristic of the streams running northerly into the relic channel. The waterfalls are recessed about 1000 feet southerly from the meltwater channel, apparently marking the extent of post-glacial headward erosion away from the "hanging" positions they would have had along the channel wall when the glacier melted away.
The swampy knob and kettle terrain to the south represents an end-moraine near the crest of Concord Drive.

STOP 5. Distant Inlet Channel And A Panoramic View Of Proglacial Lake Shumla.
This is the outlet col for pro-glacial Lake Shumla (Fairchild, 1907), formed as ice dammed the northerly flowing Canadaway Creek. The outlet elevation, controlling the lake surface, is 1105 feet. Visibility permitting, we will use a surveying instrument to view an inlet channel that brought a flood of meltwater into Lake Shumla; the inlet can be seen as a shallow topographic dent along the hilltop located about 3 miles to the northeast.
For a wider perspective of the outlet channel, fold the map on the preceding page into this page and match it to the map at right.
Also on the map, note the notch in the hillside northwest of our stop. This could have been an outlet for a lower level of Lake Shumla.

STOP 6. Ditch Exposure Of Laminated (Varved?) Clays With Dropstones
As Deposited Into Proglacial Lake Shumla.
We are 130 feet under the water surface of Lake Shumla where fine clay particles settled to the bottom. Some investigators have classified the clays as varved, interpreting the rhythmic laminations as seasonal variations in depositional environment. The roadway is "Old Route 60," while present Route 60 is located over the knoll to the east and is also cut through lake clays. The slump-prone sediments have been a problem for highway engineers for nearly 30 years, and we will drive through a clay cut that has yet to be worked into a stable angle of repose.
Lake Shumla was formed several times and at several water levels during the Pleistocene glacial oscillations, so the clays we see are not likely the result of just the most recent glaciation.

OPTIONAL STOP: Laminated clays which were deposited into Lake Shumla
This is an optional stop due to the safety constraints put on us by a large group. This is a fine exposure of laminated clays which were deposited into Lake Shumla. When NY Route 60 was initially cut through this area the engineers placed a 90 degree roadcut through this material. Over the following years the material slumped every time it was water laden until it reached the much stabler shallower exposure that appears today. As you climb up the exposure you will see beautiful clean clay littered with abundant dropstones.

STOP 7. Gravel Pit In The Deposits Of A Probable Delta Built Into Lake Shumla.
This gravel pit is near Lake Shumla's inlet. We appear to be in a delta deposited and worked by meltwater flowing from the channel and upper lake located northeast of here. Lake Shumla provided a quiet "sink" for sediments in the meltwater chain: the coarse-grain sediments settled at the delta, and the fine-grained clays deposited at mid-lake, while little or no sediment was carried by the meltwater just as it spilled out the channel to the southwest.

STOP 8. Spectacular View Of The Col Which Was The Outlet Of Proglacial Lake Shumla.
This stop presents a rather spectacular overview of the outlet channel of Lake Shumla. It appears as a dramatic V-notch in the hilltop about 2 miles to the west.
As you view the channel, mentally re-construct a mountain of slushy ice overhead, thickening northeasterly, toward Buffalo, and thinning to an end moraine gushing with meltwater within 2 miles to the south. We are about 150 feet above the lake, looking down on the 2.5 square-mile surface of frigid water. Can you spot any icebergs?

Proceeding down the south wall of the channel.

Passing through the bottom of the channel.

Passing up the north wall of the channel.

Passing down the north wall of the channel.

Passing up the south wall of the channel.

Proceeding up a long slope onto the Escarpment
Proceeding up a long slope onto the Escarpment which is the northern edge of the Allegheny Plateau.

Passing over an asymmetrical terrace above the south wall of the channel.

Passing over a terrace which is the crest of the southern wall of the channel.

STOP 9. Cross-Sectional View Of Channel And Terraces.
We have just driven through the meltwater channel and are parked near its northerly crest. Our route is depicted by the cross-section inset at left. Compare the section to your view looking southerly, down into and across the channel. Note the terraces on the southerly,wall, which were apparently cut by ice-marginal streams walled by the glacier on their northerly sides.
On the map, note the deep, dry channel easterly and southeasterly from our stop. This was the spillway for a pro-glacial lake, with a surface elevation of 1205 feet, that formed over the Forestville area as ice dammed the northerly flowing Walnut Creek. Our field trip ends here, so we'll save Lake Forestville and its inlets for a new day and a fresh paddle.
Before we depart, examine the brass disk set in concrete near the southwestern corner of the road intersection. It is a horizontal ground control station for the photogrammetrically-produced 7.5-minute-series topographic sheets. USGS designates it "IT 38 WX 1952," with position determined at 42°27'07.544" north latitude and 79°14'12.489" west longitude.