NYSGA 1999

NYSGA 1999
NEW YORK STATE GEOLOGICAL ASSOCIATION
71st Annual Meeting
FIELD TRIP GUIDEBOOK
Gordon C. Baird, NYSGA Coordinator
Gary G. Lash, Guidebook Editor
Department of Geosciences
SUNY College at Fredonia
Fredonia, NY
Second printing, April 2000
Due to the insertion of superfluous pages in the original guidebook, removed from this edition, pages Sat. F5 and Sun C 24 appear to be missing herein. This is not the case. The text is intact.

SatA: THE FIRST GREAT DEVONIAN FLOODING EPISODES IN WESTERN NEW YORK - RE-EXAMINATION OF UNION SPRINGS, OATKA CREEK, AND SKANEATELES FORMATION SUCCESSIONS (LATEST EIFELIAN-LOWER GIVETIAN) IN THE BUFFALO-SENECA LAKE REGION
Baird, G.C.
Department of Geosciences
State University of New York College at Fredonia
Fredonia, New York 14063
Brett, C.E.
Department of Geology
University of Cincinnati
500 Geology/Physics Building
Cincinnati, Ohio 45221
Ver Straeten, C.
University of Wisconsin: Oshkosh
Oshkosh, Wisconsin 54901
INTRODUCTION
The lower (sub-Ludlowville Formation) part of the Hamilton Group in western New York has received little attention by geologists owing to poor exposure and to the perception that it is composed essentially of drab, unfossiliferous deposits. Reexamination of numerous sections and several subsurface cores of Onondaga Group and lower Hamilton Group strata by Brett and Ver Straeten (1994) and Ver Straeten et al. (1994) has led to significant revisions of published correlational schemes (Rickard, 1975, 1984). In particular, the old formational division of the lower Hamilton Group (Marcellus Formation) has been elevated to subgroup status and is now understood to include two formational entities (Ver Straeten et al., 1994); the Union Springs Formation (Bakoven Member-Hurley Member-succession) comprises the lower part of the Marcellus subgroup and the Oatka Creek Formation (Cherry Valley Member through Chittenango Member-succession) represents the upper part (Fig. 1). The above terminology of Ver Straeten et al. (1994) is employed herein (Figs. 1, 2). Two of us (Baird, Brett) are involved in ongoing revision of the Union Springs-through-Skaneateles formational successions across central and western New York as, well as central Pennsylvania. Only a small portion of this work has yet been set in print; Meyer, working under supervision of Baird, revised the stratigraphy of the Stafford Member (basal Skaneateles Formation) and elucidated its relationship with the Mottville Member (Meyer, 1985). A spectacular erosionally furrowed discontinuity surface (see STOP 6) has been described from the lower medial part of the Levanna Member in Erie County (Brett and Baird, 1990; Baird and Brett, 1991). The stratigraphic relationships of basinal Chittenango Member and Levanna Member facies in western New York with coarser, shoreward deposits in central New York are the subject of detailed scrutiny by Brett and Baird.
The present paper advances an overview of the stratigraphy of the topmost Onondaga Group and sub-Centerfield Hamilton interval between the Seneca Lake meridian and Lake Erie noting revisions to date. We also tentatively explain vertical and lateral lithologic changes in terms of an inferred sea level curve and the sequence stratigraphy paradigm. Key background sources on the stratigraphy of this interval by earlier workers include: Cooper (1930); Smith (1935); Rickard (1975, 1984); Grasso (1986); Linsley (1991); Brower and Nye (1991); Brett and Ver Straeten (1994); and Ver Straeten et al. (1994). Because the Union Springs, Oatka Creek, and, especially, the Skaneateles formational successions are poorly exposed, we can only focus on a few key beds and distinctive intervals in the present report.

SatA: THE FIRST GREAT DEVONIAN FLOODING EPISODES IN WESTERN NEW YORK - RE-EXAMINATION OF UNION SPRINGS, OATKA CREEK, AND SKANEATELES FORMATION SUCCESSIONS (LATEST EIFELIAN-LOWER GIVETIAN) IN THE BUFFALO-SENECA LAKE REGION

Cross over I-390; view of three drumlins to the right (south)

Small outcrop of Onondaga Limestone on right along Works Road.

STOP 1: General Crushed Stone Quarry, Honeoye Falls Plant.
Quarry north-northwest of Lima, New York (RUSH 7.5' Quadrangle). Pit is located on south side of Honeoye Falls #6 Road, 6 km (3.4 mi) east of the Honeoye Falls #6 Road/Route 15 intersection.
PERMISSION TO ENTER QUARRY MUST BE OBTAINED BEFORE ENTERING. Hardhats required!!!
This is a classic exposure of the Onondaga Limestone and the basal portion of the Hamilton Group (see extensive treatment by Brett and Ver Straeten, 1994; Ver Straeten et al. 1994). We will proceed southeastward on foot from the quarry road terminus at the southwest edge of the pit along the conspicuously sloped next-to-top riser. Note the exceptional jointing of the limestone at various quarry levels and the southward dip throughout which is steeper than the 0.5° average for the region. The riser on which we walk is developed on the top-contact of the Moorehouse Member of the Onondaga; choice of this horizon as a staging surface in the quarry probably relates to the position of the soft Onondaga Indian Nation (OIN) K-bentonite which allowed for easy peel-back of overlying beds. This ash is 25 cm-thick at this locality. The OIN K-bentonite is the thickest of a series of closely-spaced ash beds known as the "Tioga Ash Complex" in literature (Conkin, J.E. and B.M. Conkin, 1984; Rickard, 1984). Dennison and Textoris (1978) believe that "Tioga" tuffs originated in what is now northern Virginia and the prevailing paleowinds carried the volcanic products predominately westward (in the present sense) into the U.S. midwest. Several higher, thinner K-bentonites can be seen in the Seneca Member (quarry wall above OIN position) as reentrants. Some of these are associated with chert bands (see discussion of Ver Straeten et al., 1994) of detailed ash succession (Fig. 4).
Crinoidal, brachiopod-rich limestone marking the top of the Seneca Member is abruptly succeeded by the Bakoven Member where a 2-3 mm-thick black shale bed is draped upon a minor discontinuity at the top of the Onondaga (Fig. 4). This is, in turn succeeded by a 15 cm-thick K-bentonite layer (Tioga F Ash) and platy styliolinid-rich limestones that overlie the ash. Within the interval of styliolinid limestones is a bone bed rich in onychodid teeth, arthrodire dermal armor and conodonts. Very large specimens of Panenka, a bivalve typical of dysoxic facies, occur within the styliolinid limestone interval as well. Succeeding Bakoven strata are composed of platy black shale facies (Fig. 4). In this quarry, the Bakoven Member ranges from 1.7 m to as little as 7 cm in thickness due to variable truncation below the sub-Cherry Valley unconformity (Ver Straeten et al., 1994).
The Chestnut Street submember of the Hurley Member is only locally exposed in this quarry (Fig. 4); it is expressed as a light weathering richly fossiliferous limestone bed at the eastern end of the exposure. The proetid trilobite Dechenella haldemanni, auloporids, sponge spicules and diminutive calyces of the crinoid Haplocrinites are characteristic fossils. Removal of almost all of the Chestnut Street bed and all post-Chestnut Street Bed Hurley strata reflects channelized downcutting associated with a disconformity at the base of the Cherry Valley Limestone (Ver Straeten et al., 1994).
The Cherry Valley Member of the Oatka Creek Formation is represented by 0.4 to 3.0+ meters of crinoidal pack-and grainstone carbonate containing lesser amounts of styliolinid and fenestrate allochems. Major variation in Cherry Valley thickness at this locality apparently reflects paleorelief at the base of the unit owing to the presence of paleochannels associated with differential erosion of the Bakoven Shale (Ver Straeten et al., 1994). Sparse conchs of the characteristic goniatite Agoniatites and the orthoconic cephalopod Striacoceras have been found at this locality. A pyrite coated corrosional discontinuity marks the contact between the Cherry Valley limestone and overlying black shale facies of the Berne Member of the Oatka Creek formation (Fig. 4). At last visit about 1. 5 m of this shale was exposed below till at the uppermost bedrock limit; to date, the Halihan Hill Bed has not been uncovered in this section.
The Honeoye Falls quarry section is significant in that it displays the westernmost occurrences of the Bakoven Shale, Chestnut Street submember, and Cherry Valley Limestone that can be seen in outcrop (Figs. 4, 5). At STOP 3a, the Berne Member is juxtaposed directly onto the Seneca Member with development of a composite unconformity between them (Figs. 5, 6). STOP 1 is significant in showing no less than four discontinuities: base-Bakoven, lower-Bakoven, sub-Cherry Valley, and sub-Berne contacts that ultimately contribute to the large composite hiatus at LeRoy.

STOP 2. Levanna Shale Member.
Type section of Papermill Limestone and associated beds of uppermost part of Delphi Station-equivalent Levanna (see Fig. 9).
The footbridge over the creek near the parking area, provides a good look at the resistant limestone ledge of the Papermill Bed. This unit was misidentified as Stafford in early literature. At this locality, the Papermill is composed of bioturbated mudstone characterized by few fossils. The most notable bed content consists of three-dimensional barite infilled orthoconic cepholopods and infrequent clumps and masses of barite. The top of the Papermill Bed near the foundation of the Paper Mill Road overpass is marked by a thin bed of auloporid corals and other fossils (Fig. 9); this is the Roanoke Bed which is better developed at STOP 4 (Fig. 8). Upstream from the Paper Mill Road bridge are good exposures of both Pole Bridge Limestone layers and still further upstream is good development of the Wadsworth Bed (see text). The upward succession of Papermill Bed-lower Pole Bridge Bed-upper Pole Bridge Bed-"Tasmanites Shale" interval marks a stepwise overall marine deepening that marks the change from upper Delphi Station lowstand conditions to basal Pompey cycle highstand facies (see text).

Cross Conesus Creek at Ashantee.
Onondaga Limestone (Seneca Member) is exposed both below and above Route 39 bridge.

Bridge over Genesee River

Leave Genesee River floodplain.

Pass through Limerock.
Proceed towards LeRoy; route passes south of 5 to six large quarries developed into the Onondaga Limestone.

Cross over Oatka Creek
Falls over Stafford Limestone immediately north of bridge.

STOP 3. Bed of Oatka Creek
North of (downstream from) Route 5 in town of LeRoy (LeRoy 7.5' Quadrangle). Creek parallels small park along Mill Street. Outcrop floors creek between falls over Stafford Member near dam and railway bridge to the north of a park footbridge over creek (Fig. 6).
This section offers a variably accessible but nearly continuous section from the uppermost Seneca Member up to the Stafford Limestone (Fig. 6). We will first park in the northernmost parking area where Mill Street turns west immediately north of the railroad overpass (STOP 3a). We will then drive south past two houses and a footbridge to the next park pull-off to the south of STOP 3a (STOP 3b) and finally to the main parking area near the southern end of Mill Street (STOP 3c). Proceed on foot from 3a pull off to edge of creek.
STOP 3a: Halihan Hill Bed and basal Chittenango Member of the Oatka Creek Formation.
Although the Seneca Member-Berne Member composite unconformity was excavated by Baird on this creek in the mid 1980s, the contact is currently concealed by debris. However, one can sample richly fossiliferous Seneca facies just below the contact level on this creek at the present time. The sub-Berne disconformity is expressed as a pyrite-coated irregular, pitted surface with phosphatic lag debris in depressions on the contact (Baird and Brett, 1991). The Berne Member is poorly exposed below water to the north of our access point (Fig. 6). This 40 cm-thick unit is composed of black shale rich in large styliolinids.
At this section, the Halihan Hill Bed is also exposed below water (Fig. 6). However, the upper part of this unit is within the reach of hammers if the water is not high. The 60 cm Halihan Hill interval is composed of very soft, gray shale which yields diverse and abundant fossils. Key brachiopods at this locality include Mediospirifer audaculus, Athyris cora, Tropidoleptus sp., Devonochonetes sp., Ambocoelia umbonata, Pseudoatrypa devoniana. Other fossils include stereolasmatid corals, encrusting, bifoliate and fenestrate bryozoans, pteriomorph bivalves, Phacops exuviae and pelmatozoan debris. The bed marks the dramatic appearance of the Hamilton macrofauna that holds sway in the study area for most of the Givetian Stage.

STOP 3b: Black, organic-rich shale deposits
Black, organic-rich shale deposits of the Chittenango Member of the Oatka Creek Formation.
This brief stop serves to illustrate the exceptionally organic-rich facies of the Chittenango Member. Well jointed, very hard black shale is exposed in the creek bed. This part of the Chittenango displays T.O.C. values exceeding 15%. Although no macrofauna is observed in this facies, a thin (1 cm-thick) debris layer of orbiculoid fragments is observed in the lower Chittenango in the vicinity of the park pull-off.

STOP 3c: Stafford Limestone Member of Skaneateles Formation
Stafford Limestone Member of Skaneateles Formation and uppermost strata (Chittenango Shale Member) of Oatka Creek Formation exposed in waterfall below dam. Section easily viewed from viewing platform by parking lot (Fig. 6).
Below the conspicuous Stafford limestone ledge are several feet of black to dark gray fissile shale assignable to the Chittenango Member. Some of the highest beds are not as black and organic rich as typical Chittenango. Moreover, they yield flattened rhynchonellids and orbiculoids below the base-Stafford contact. Although not formally used here, the term "Cardiff Shale" is marginally applicable to these beds (see above). Further east in the vicinity of Skaneateles, the upper part of the Chittenango transforms eastward into gray, fissile shale that has been formally assigned to Cardiff
At this section 78 cm of Stafford Member, including a lower calcareous dark gray shale interval and 28 cm of resistant limestone, are present in the falls. The uppermost calcareous shale portion of Stafford is concealed here. As with other Stafford sections in the Waterloo-Stafford region, the member is thin and distinctly condensed. Unlike sections in Erie County (Meyer, 1985) and in Onondaga and Madison Counties (Grasso, 1986), where two prominent ledges ("A" and "B" beds) respectively characterize Stafford and Mottville sections, the LeRoy Stafford section is characterized by a single limestone unit underlain by a brachiopod-rich shale unit (Fig. 6). The shale interval below the limestone is typically characterized by abundant Ambocoelia and Devonochoneaes. The falls-capping limestone bed contains Camarotoechia sappho, Bembexia sulcomarginata, occasional small rugosans, auloporids and uncrushed orthoconic nautiloids. The matrix is a brownish gray wackestone lithology, fossils are typically three dimensional and mollusc shell is expressed as sparry black calcite.
Due to the thinness and minimal differentiation of the limestone part of the Stafford in this area, it is difficult to connect the "A" and "B" bed terminology o fMeyer (1985) for Erie County and the "A" and "B" bed-usage of Grasso (1986) for Onondaga County (see text). We suspect that the regressive lowstand marked by a scour surface at the base of Grasso's "A" bed encrinite in Onondaga County roughly links to the base of the limestone bed at LeRoy, but this is, as yet, unproven.

STOP 4: Levanna Shale Member of Skaneateles Formation (Fig. 8).
This exposure shows Papermill Limestone Bed, Roanoke Bed, probable "Tasmanites Shale" with subjacent diastem, Wadsworth Bed, and an overlying unnamed shale unit in the upper Levanna (see text). The exposure is partly below water in bed of Oatka Creek 200-250 m east of (downstream from) Covell Road overpass (Stafford 7.5' Quadrangle). The outcrop is 6 km (3.5 mi) southwest of LeRoy, NY. We will access outcrop by entering through a private driveway exiting off of road immediately south of the creek that terminates at a residence near the exposure.
Several key Levanna beds occur in this section nearly juxtaposed on one another (Fig. 8). At the northeast (downstream) end of the section, is the Papermill Bed, a 0.7 m-thick massive limestone marker in the upper-middle part of the Levanna. This unit, yielding few fossils, marks one of the highest levels in that portion of Levanna that we believe is equivalent to the Delphi Station Member (see text: Fig. 8). Above the Papermill ledge is a 25 cm-thick interval of profusely fossiliferous, soft, gray mudstone yielding thicket growths of a large variety of Aulocystis (Fig. 8). This mudstone unit, herein designated the Roanoke Bed with this locality as its type section (see text), is mostly exposed below water. On Oatka Creek, this bed is thickest and best developed; the Aulocystis thicket layer yields brachiopods such as Pseudoatrypa and Rhipidomella and crinoid debris is abundant. Above the thicket layer is a 0-10 cm thick interval of soft gray mudstone yielding Arthracantha fragments and large Phacops. This unit marks the faunal acme of the entire Levanna in this region; it probably marks a sea level lowstand coincident with a maximally regressive part of the Delphi Station cycle in central New York (see text).
At Stop 4, the Roanoke Bed is abruptly and unconformably succeeded by a 40 cm-thick interval of fissile, dark gray to near black shale (Fig. 8). The Roanoke-black shale boundary is knife-sharp and it is marked by abundant reworked pyritic burrow tube fragments. These fragments, derived from in-situ pyritic burrow networks in the Roanoke Bed, locally show a weak current alignment. The tubes are identical to those observed in the Leicester Pyrite Member and in higher Genesee Formation levels; we believe that they were exhumed under dysoxic to near-anoxic conditions, most likely by bottom current processes or the shoaling of internal waves (Baird and Brett, 1991 ). Also significant is the scarcity of carbonate allochems associated with the tubes despite the abundance of carbonate fossils in the Roanoke. Baird and Brett (1991) argued that under lower dysoxic to near-anoxic bottom conditions, reworked pyrite could remain unoxidized when exposed to the sea bed while carbonate allochems would undergo dissolution. This reversal of the normal oxic situation could explain the lack of carbonate in detrital pyrite-dominated lags. The black shale above the discontinuity yields flattened rhynchonellids ("Leiorcynchus") and abundant Tasmanites. We believe that this unit is a beveled remnant of a thicker organic rich unit ("Tasmanites Shale") observed in the Genesee Valley (Fig. 9).
Above the dark shale unit is a 8-10 cm-thick bed marked by abundant fossils (Fig. 8). This is the Wadsworth Bed that is composed of a muddy hash of small brachiopods (Devonochonetes, Ambocoelia), minor pelmatozoan debris, auloporid thicket and debris fabric and Tasmanites set in a network of Thallasinoides burrows (see text). Conodonts and small fish bones and teeth are also present in this bed, though less conspicuous than at the base of the black shale. These are commonest in burrows at the base of the bed; their distribution suggests that the base of the unit is erosional and that this erosion explains the anomalous thinness of the underlying black "Tasmanites" Shale unit. This unit can be traced into the Genesee Valley, but only tentatively east of there (Fig. 9); it may correlate to the Nyassa arguta-rich sandstone at the top of the Pompey Member in central New York (see text). To the west it may connect to the Union Road discontinuity that we will see at STOP 6.
Above the Wadsworth Bed is a monotonous interval of dark gray fissile shale that is visible in the upstream, north-facing shale bank. These shales yield a sparse biota of Devonochontes scitulus, flattened rhynchonellids ("Leiorhynchus"), small Ambocoeliids and diminutive gastropods and bivalves. Based on correlations to date, we are involved in ongoing efforts to determine whether this unit is part of the Pompey or the next higher "Marietta Cycle" (see text).

Small exposure of Kashong Shale on East Road north of Intersection.

Exposure of Genundewa Limestone Member
Exposure of Genundewa Limestone Member of the Genesee Formation (Upper Devonian: lower Frasnian) on left (south) side of Route 20 beneath Bethany Center Road overpass. The Genundewa is a styliolinid-rich limestone rich in cephalopod conchs at this locality and, along with the Cherry Valley Member is a classic cephalopod limestone.
Not much geology is visible from Route 20 over this 25 mile distance, though numerous classic upper Hamilton Group localities occur near the read in this area.

STOP 5. "A Bed" at base of Mid Dev Stafford Limestone Member
STOP 5. (optional): "A Bed" at base of Middle Devonian Stafford Limestone Member at Como Park (Fig. 7):
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 (Fig. 7). Downstream from the waterfalls are intermittent exposures of the black, fissile, organic-rich Chittenango Member of the underlying Oatka Creek Formation which is mostly covered. Near the falls and bridge, the topmost few feet of the Chittenango Shale can be examined on the south side of the creek; these uppermost Oatka Creek beds are dark gray-brown in color and they yield a meager dysoxic biota consisting of flattened rhynchonellids ("Leiorhynchus"), Styliolina, and numerous flattened composite molds of an orthoconic nautiloid.
The Stafford, in Erie County, is a four-part member consisting of a basal, thin, shell-rich muddy limestone bed ("Sub-A" bed), a slightly higher limestone unit with encrinite at its base (probable "A" bed of central New York Mottville), a middle, shaley interval several feet thick which contains nodular, micritic, concretionary beds, and a fossiliferous upper cherty limestone division, termed the Stafford "B" bed, which is 0.6-1.3 m (2 to 4 feet) in thickness (see Meyer, 1985). In central New York, the equivalent Mottville Member starts with a fossiliferous, calcareous mudstone division ("sub-A" bed) followed by an encrinite-rich "A" bed limestone ledge, which is succeeded, in turn, 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 (see text). The "sub-A" bed remains relatively thin, usually between 8 and 30 cm (0.2-1.0 feet) in thickness in this area, and it is typically a densely fossiliferous calcareous mudstone, both overlain and underlain by sparsely fossiliferous deposits (Fig. 7). The "sub-A" bed typically rests abruptly on dysoxic to anoxic dark shales. The "middle shale" usually grades upward into fossil-rich shaley micrites of the "B" bed.
At this locality the Stafford "sub-A" bed yields numerous small brachiopods, including Crurispina nana, Truncalosia truncata, Devonochonetes scitulus, and a small variety of Tropidoleptus. Other fossils include the large bivalve Panenka, occasional Camarotoechia, orthoconic nautiloids often encrusted by the reptate biserial tubular organism Reptaria stolonifera, which may have "hitchhiked" on the living cephalopod (see Baird et al., 1989), and wood debris. The diminutive brachiopod assemblage in the Stafford "sub-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.
Middle Devonian black and dark gray shales of the Chittenango Member are intermittently exposed along creek in this area.

Cross Cayuga Creek

Onondaga Limestone with associated Tioga ash beds
Two excellent exposures of the upper part of the Onondaga Limestone with associated Tioga ash beds are respectively developed on Cayuga Creek adjacent to the road 0.5 and 1.5 miles west-southwest of the Broadway/Rowley Road intersection (Brett and Baird, 1990).

Cross Cayuga Creek.
Middle Devonian Onondaga Limestone is exposed both below bridge and upstream from it.

Cross Buffalo Creek.
Excellent exposure of Levanna Member that we will examine is developed below bridge.

STOP 6. Submarine Discontinuity (Union Road disconformity)
Submarine Discontinuity (Union Road disconformity) within Middle Devonian Levanna Shale Member along Buffalo Creek (Figs. 9, 10).
Along this cutbank exposure one can observe two key Levanna lithologic divisions which are currently unnamed. Just above water level is a calcareous, dark gray-shale division which yields the diminutive brachiopod Ambocoelia and specimens (many 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 flattened rhynchonellids ("Leiorhynchus") and Styliolina. This boundary is probably correlative with the Wadsworth Bed in the Black Creek-Conesus Creek area (Figs. 5, 9). 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 m (1.5-6.5 feet) in width and between 12 and 45 cm (5 to 16 in) in depth alternate with intertrough ridges and platforms (Fig. 10). 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. 10B). 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 commonly 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. 10C). 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 across the disconformity 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 (see 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, 1983). 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.

SatB1: SILURIAN-EARLY DEVONIAN SEQUENCE STRATIGRAPHY, EVENTS, AND
PALEOENVIRONMENTS OF WESTERN NEW YORK AND ONTARIO, CANADA
CARLTON E. BRETT
Dept. of Geology
University of Cincinnati
Cincinnati, Ohio 45221-0013
The Sear-Brown Research Group
85 Metro Park
Rochester, NY 14623
STEVEN T. LODUCA
Dept. of Geology and Geography
Eastern Michigan University
Ypsilanti, MI 48197
DENIS TETREAULT
Dept. of Earth Sciences
University of Western Ontario
London, Ontario N6A SB7
INTRODUCTION
The Silurian rocks of the Appalachian Basin provide an excellent suite of strata for application of sequence, and event stratigraphic approaches. The strata are well exposed and display marked vertical changes in facies, commonly associated with distinctive condensed beds and/or discontinuities. The Niagara Escarpment in western New York and the Niagara Peninsula of Ontario represents a key reference area for the North American Silurian System. Indeed, the term "Niagaran," which has been variably applied to the "middle" or lower and middle portions of the Silurian, is still commonly used in North America. These rocks have been well documented by many researchers, beginning in the mid 1800s (Hall, 1852; Grabau, 1901; Williams 1919; Gillette, 1947; Bolton, 1957; Zenger, 1965, 1971; Sanford, 1969; Martini, 1971; Rickard, 1975; Brett, 1983 a,b; Brett et al., 1995; 1998).
A major theme of this report and field trip is the documentation and interpretation of Silurian facies and sequences along the northwestern rim of the Appalachian Basin. The larger scale ("third order") sequences described herein are unconformity bound stratal packages, ranging from less than a meter (where partially truncated or condensed) to about 50 m in thickness. Most display a generally deepening-shallowing pattern. They are divisible into smaller (fourth-order) sequence-like units that display similar patterns but are not separated by major unconformities; we have termed these units subsequences (see Brett et al., 1990a, b, 1995, 1998, for further details).
With its renewed emphasis on through-going discontinuities and condensed beds, the sequence approach has encouraged a broader, more regional view of stratigraphy and an attempt to understand the genetic significance of particular beds and surfaces. To some degree it vindicates the earlier "layer cake stratigraphy" approach. Sequence stratigraphy, originally developed from remote seismic studies of passive margin sediment wedges (Vail et al., 1977, 1991; Wilgus et al., 1988). is now being applied at an outcrop scale to diverse depositional settings including foreland basins such as the Appalachian (or Taconic) foreland basin of the Ordovician and Silurian (Brett et al., 1990 a,b; Witzke et al., 1996; Brett et al., 1998). Many distinct surfaces in the local stratigraphic record are interpretable as sequence boundaries or flooding surfaces. Moreover, a number of phenomena which occur non-randomly in the geologic record, from phosphatic nodule horizons to reefs fit in predictable ways into depositional sequences.
A secondary theme of this article is the recognition of widespread events, such as storm deposits (tempestites), rapidly buried fossil horizons (obrution deposits), and even seismically deformed beds (seismites). A variety of such catastrophic events are recorded in the Silurian rocks of the Niagara region and will be examined on this trip.
STOP DESCRIPTIONS This field trip will take place in western New York State and in the Niagara Peninsula of Ontario. Figure 15 shows stop locations for the trip on a simplified geologic base map (Rickard and Fisher, 1970). Abbreviations used in the text and figures for inferred sequence stratigraphic units are as follows: for subsequences (fourth order sequences): RLS =relative lowstands (regressive deposits); RHS =relative highstands; MFS =marine flooding surface; SDS =sea level drop surface; CI, condensed interval, and for sequences: SMT = shelf margin systems tract (lowstand deposit); TST = transgressive systems tract; CS = condensed section; EHS = early highstand; LHS = late highstand; SB = sequence boundary; TS = transgressive surface. The sequences referred to in the previous text are abbreviated as S-I through S-VIII in the following.

SatB1: SILURIAN-EARLY DEVONIAN SEQUENCE STRATIGRAPHY, EVENTS, AND
PALEOENVIRONMENTS OF WESTERN NEW YORK AND ONTARIO, CANADA

Silver Creek Exit
Note Portage Escarpment with cuts in gray Hanover Shale overlain by black Dunkirk Shale; Upper Devonian, near Frasnian-Famennian boundary

Cuts in Rhinestreet Shale
Note sulfurous black shale with large concretions; Upper Devonian (Frasnian)

Middlesex Shale

Ledge of North Evans Limestone on right
This is a highly condensed conodont, bone-rich limestone that straddles the Middle- Upper Devonian boundary

Note large steel mills

Father Baker Bridge
Views of Buffalo Harbor and City Skyline

Underpass under Peace Bridge
Views of Black Rock Channel of Niagara River

Toll Booth for South Grand Island bridge;
Views of east branch Niagara River (pay toll; $.50)

Enter Grand Island, NY
One of the largest river surrounded islands in the World; about 9 miles long north to south

North Grand Island bridge
Views of broad Niagara River about 2 miles above the Falls.

Views of retaining wall of large toxic waste storage area

Pass under major power lines from hydroelectric plant

Pass by fisherman's parking area
Pass by fisherman's parking area (cars can be left here; we will continue on South Haul Road to the bottom of the gorge and allow passengers to disembark and return uphill on foot); ahead through underpass beneath Robert Moses Parkway are excellent views of the Niagara Gorge and a complete stratigraphic section from the mid Silurian Lockport Group down to the unconformable contact between the Silurian Whirlpool Sandstone and the underlying Ordovician Queenston Shale.

Fishermen's access at bottom of Niagara Gorge
Fishermen's access at bottom of Niagara Gorge, just outside gates for Robert Moses Power Plant; passengers will disembark and proceed back up the South Haul Road; vehicles will return back up the road to park

STOP 1. NIAGARA GORGE - SOUTH HAUL ROAD
Location: Large roadcuts in east wall of Niagara Gorge along South Haul access road for Robert Moses Power Plant, and ascending for about 1 km south to a tunnel beneath Robert Moses Parkway (Fig. 16). Parking is available in a fisherman's access parking lot just west of Rt. 62 (Hyde Park Boulevard) immediately south (uphill) from the tunneL Lewiston, Niagara County, New York (USGS Lewiston 7.5' Quadrangle). Note: Access to the Haul Road exposure is strictly controlled by the Robert Moses Power Project and requires advance permission.
Description: This outstanding outcrop of Lower to mid Silurian strata shows important contrasts with sections of the comparable interval near Hamilton. The section begins near the Power Plant with about 8 m of the Upper Ordovician Queenston Shale (Fig. 17). Its sharp contact with the overlying Whirlpool Sandstone is the Cherokee Unconformity (Silurian Sequence I boundary). The units of the Silurian succession are described in ascending order, as follows:
Medina Group (Fig. 17).
Whirlpool Sandstone: (4.5 m)- White, trough cross bedded, quartz arenite facies which record a non-marine to marine transition. Excellent profiles of channels are visible.
Power Glen Shale: (- 8 m)- Dark gray, friable shale, with very minor sandstone interbeds
Devils Hole Sandstone: (2 m)- Pale gray, massive, quartz arenite with a distinctive, meter-thick phosphatic, sandy dolostone, Artpark Phosphate Bed near the top (CI).
Grimsby Formation: (15 m)- Greenish gray to maroon shales and mudstones with bundles of thin reddish and white mottled sandstones (Fig. 17). (/) NM
Thorold Sandstone: (2 m)- White, cross-bedded quartz arenite. The Thorold has a sharp, erosive base which marks the base of the next Medina subsequence (IC). A thin (2- 10 cm), sandy phosphatic bed, the Densmore Creek Bed (Brett et al. 1995) rests sharply on the Thorold (and on a Cambria Shale remnant north of the Power Plant), marking the base of the Neahga Shale.
Clinton Group (Figs. 6, 18)
Neahga Shale: (2m)- Dark greenish gray, very friable shale (base sharp (S-11 SB).
Reynales Formation (Hickory Corners Member): (-50 cm)- Medium gray, nodular, burrowed, bryozoan-rich wacke- to packstone. Conodonts indicate a mid Llandovery age for the Reynales (see LoDuca and Brett, 1994); this unit represents an erosional remnant of the Reynales.
Rockway Formation: (3 m)- Buff-weathering, argillaceous dolostone with thin dolomitic shales shows prominent rhythmic bands (10-50 cm) of sparsely fossiliferous argillaceous dolostone interbedded with thin gray shales. The Rockway shows a sharp upper contact(S-IV-V SB).
Irondequoit Formation: (2.5 m)- Massive, pinkish-gray, crinoidal pack-and grainstone. Clasts of fine-grained dolostone, derived from the underlying Rockway occur in the basal thin bed of the Irondequoit (Fig. 18). Its sharp upper contact (MFS) is marked by a 30 cm thick shell bed.
Rochester Shale: (18m)- Medium dark gray mudstone with thin calcisiltites and lenticular fossil rich limestones; 1.5 m of bryozoan-rich limestone beds underlie the sharp top (MFS) of the Lewiston Member. The upper Rochester (Burleigh Hill Member) also displays a sharp contact (SSB) with the enterolithic DeCew Dolostone beds.
DeCew Formation: (3m) -Dark gray, buff weathering, laminated dolostone (calcisiltite). Here and, especially in weathered exposures in the adjacent Devils Hole Park section, the DeCew displays spectacular soft-sediment deformation with isoclinally folded beds (seismite?). Lockport Group (Fig. 19): 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; basal Gasport shows rip-up clasts of DeCew Dolostone (Figs. 19). Gasport Formation: (5 m)-Pinkish gray thin bedded to massive dolostone, divided into a lower pinkish gray dolomitic crinoidal grainstone (Gothic Hill Member) and a 2.5 m upper argillaceous, bioturbated dolostone (Pekin Member) Weathered surfaces of the Gothic Hill grainstones display probable bipolar cross- stratification . The sharp upper contact is a subsequence boundary.
Goat Island Formation: -10 m)- Buff weathering dolomitic, crinoidal grainstones, buff, thin bedded dolsotone with white chert, and dark brownish gray, argillaceous, banded dolostone; the basal unit (Niagara Falls Member) is massive crinoidal grainstone with scattered Cladopora corals and stromatoporoids; abundant vugs appear to be solution cavities in a stromatoporoid-rich zone.
The Ancaster Member is poorly developed here, thin (-2.5 m) and only sparingly cherty. Argillaceous and bituminous gray dolostones of the Vinemount Member form the uppermost unit on the access road. This member is much less shaly than at its type area near Hamilton.

STOP 2. ROBERT MOSES ACCESS ROAD AND FOREBAY
Location: Access road to the Robert Moses Power Plant, and adjacent forebay canal just west of Military Road and 1.2 km north of Route 31, Lewiston, Niagara Co., NY (Lewiston 7.5' Quadrangle).
Description: Higher units of the Lockport Group are visible along the forebay and consist of the upper Eramosa (new usage in New York) and lower Guelph formations (Fig. 19). Large algal bioherms characterize the uppermost units of the Eramosa Formation in the forebay. Exposures in the small road cut at the underpass of the access road beneath the lanes of 1-190 show exceptionally large (2m high) stromatolites, and some non-laminated thrombolites the stromatolitic interval at the base of the Guelph is traceable with subsurface data at least to Hamilton (Fig. 19).

Note dolostone church on right at Grove Street

STOP 3. "PEKIN BIOHERM" CUT ON RT. 427 (OPTIONAL )
Location: Cuts on both sides of NY 427, just north of underpass beneath Upper Mountain Road, Pekin, Niagara County, NY (Cambria 7.5' Quadrangle).
Description: This classic cut in the brow of Niagara Escarpment has recently been widened, and provides an excellent, but very fresh exposure of the upper Gasport (Pekin Member of Brett et al., 1995) and the lower portion of the overlying Goat Island Formation (Fig, 19). The large, massive mound exposed particularly on the west side of Rt. 427 was originally described as a Gasport bioherm and was considered to show reefal succession (Crowley and Poore, 1974). However, recent excavations have revealed that the mass of stromatoporoid bearing rock is almost entirely within the Goat Island Formation and is separated from older Gasport deposits (including a formerly exposed small bioherm, now destroyed by blasting) by a major erosion surface. The contact between the gray, thin bedded argillaceous dolostones of the Pekin Member of the Gasport and overlying massive, dolomitic crinoidal grainstone of the Goat Island (Niagara Falls Member of Brett et al., 1995), a sequence boundary, appears sharp, but horizontal in the northeastern portion of the cut. However, this contact abruptly descends to near road level just north of the Upper Mountain Road overpass. Here a mass of biohermal lithology overlies the unconformity. On the freshly blasted west side of the cut the irregular contact between the dark gray Pekin and light pinkish biohermal Goat Island is now very clear. The erosion surface separating the units has a relief of over 2 meters. The Goat Island "bioherm" appears to have developed in low areas on the unconformity. It consists of a mixture of crinoidal grainstones and light gray dolomicrite, rich in stromatoporoids, many of which are tumbled onto their sides or even inverted, indicating storm disturbance. This biohermal mass built up in "channels" along a sequence boundary during initial transgression.

Brow of Niagara Escarpment
On clear days good views of the mouth of Niagara River and Lake Ontario to the north; cuts to right in Gasport-Goat Island formations

Frontier House McDonald's; pull in for rest stop.
OHM 2017: The McDonalds closed in 2004.

STOP 4. NIAGARA GORGE, LEWISTON (ARTPARK) - (LUNCH STOP)
Location: Sections in east wall of Niagara Gorge along old haulage road extending from north end of Niagara Gorge at Niagara Escarpment just south of Artpark (Fig. 16); off Fourth Street, southward to the Lewiston-Queenston bridge, Lewiston, Niagara County, NY (Lewiston 7.5' Quadrangle)
Description: The north-facing cuesta (Niagara Escarpment) stands 76 m above the adjacent Lake Ontario plain. Niagara Falls was initiated here about 12,000 BP. Exposures of the Upper Ordovician Queenston Shale and its unconformable contact with basal Silurian Whirlpool Sandstone are visible along a short path, adjacent to the river, immediately south of the Artpark theater. Outcrops of the Lower Silurian stratigraphic units above the Whirlpool Sandstone (Fig. 17) are accessible along an old haulage road that leads southward from the Artpark Visitor Center into the gorge. At the entrance to the gorge (edge of Niagara Escarpment) an isolated "butte" of Lower Silurian strata (Power Glenlower Grimsby; type locality of the Artpark Phosphate bed) between the path and the river, represents a remnant of a promontory in the gorge wall that was breached during excavation for the power plant. A 0.5 m layer of mottled sandstone with prominent ball-and-pillow structures, about 5.5 m above the base of the Grimsby, is well exposed in the cliffs about 200 to 700 m north of the Lewiston-Queenston Bridge. Caution is required in this exposure, as rock falls are common. Abundant fallen debris also provides an excellent look at varied lithologies of the upper Medina, as well as Clinton and Lockport units.

Excellent views of Niagara Gorge from bridge; Canadian border

Lift bridge over Weiland Canal

STOP 5. MERRITTON RAILROAD CUT
Welland Lock# 5; parking area adjacent to canal; pull in and park: railroad cuts are to right on opposite side of the road; cautiously cross road and proceed down embankment to railroad cuts
Location: Cuts along Canadian National Railroad tracks 0.1 km west of Government Road (Canal Street) along west side of the Welland Canal, opposite locks 4 and 5, Village of Merritton, Thorold Township, Ontario. (NTS 30M/3g, St. Catharines Sheet).
Description: This locality is the type section of both the Thorold Sandstone and the Merritton Dolostone (Kilgour, 1963; Fig. 20). Units exposed along this cut include, in ascending order:
Thorold Formation: (3m)- White and greenish sands and shales with small scale cross stratification, scour and fill structure, load casts and oscillation ripple marks. The lower 1.5 m of Thorold Sandstone, interbedded pale buff-weathering argillaceous sandstone and thin greenish sandy shales with excellently preserved spreiten of the trace fossil Daedalus, while undersurfaces show the annulated trace fossil Arthrophycus both traces may have been the work of the same organisms. This is a widespread marker interval.
Unnamed limestone: (30 cm) Gray, argillaceous, phosphatic limestone with bryozoans.
Neahga Shale: (24 cm)- Dark gray shale with bored hardground clasts in basal 5 cm.
Merritton Limestone: (50 cm)- Pale gray, glauconitic, phosphatic wacke- to packstone with three major beds as in the Hamilton area . Basal contact sharp, with abundant small phosphatic nodules. The upper contact of the Merritton is also a sharp, shows truncated in situ Pentameroides a (Telychian index fossil) and is stained black with phosphatic material.
Williamson Shale: (12 cm)- Greenish gray shale tentatively correlated with the Williamson Shale of New York on the basis of recovered acritarchs (C.E. Brett and M. Miller, unpublished data).
Rockway Dolostone: ( ~ 2 m)- Buff to gray, thin bedded argillaceous dolostone with an abundance of the large pentamerid brachiopod Costistricklandia. This cut is crucial in establishing the stratigraphic succession of the lower to mid Clinton rocks in Ontario. The Merritton (often called "Reynales" in Ontario) overlies the major late Llandovery (Sequence IV basal) unconformity, which at this locality has removed the true Reynales Limestone (Figs. 6, 20).

STOP 6. BURLEIGH HILL ROAD CUT. (OPTIONAL )
Location: Exposures in long roadcut in brow of Niagara Escarpment along Burleigh Hill Road about 2 km south of Glendale Avenue, Thorold, Ontario (NTS 30M/3g, St. Catharines Sheet).
Description: This long cut exposes the upper portion of the Rochester Shale and its contact with the overlying DeCew Formation (Figs. 9; 18). This is the type locality of the Burleigh Hill Member of the Rochester Shale (Brett, 1983b); which is here about 9 m thick. It is divisible into lower shaly and upper somewhat thicker bedded, dolomitic shale and argillaceous dolostone. Thin calcisiltites display sharp bases and small scale grading and hummocky cross stratification indicative of deposition as tempestites (storm beds); fossils are generally sparse although rare Stegerhynchus and Coolinia brachiopods and the trilobites Dalmanites and Trimerus can be found. The DeCew Formation is less than a meter thick and displays typical highly convoluted bedding as seen at Niagara Gorge. The contact with a thin 40-50 cm ledge of atypically fine gained Gasport Dolostone is sharp; locally a very thin remnant of a fossiliferous shale (the St. Catharines shale lentil) are present between the DeCew and Gasport but that unit is largely removed by sub-Gasport erosion.

Cross Welland River

Tunnel beneath Welland Canal

STOP 7. RT. 58A CUT NEAR TUNNEL BENEATH WELLAND CANAL (OPTIONAL )
Location: East entrance to the Town Line) Netherby Road and railway tunnel beneath the Weiland Canal Bypass, southeast edge of Weiland, Ontario (NTS 30L/14g, Weiland Junction Sheet)
Description: Strata here are assignable to the Upper Silurian Salina Group (Fig. 21).
Camillus Formation - (5 m exposed) - Interbedded fine-grained blocky to laminated, gray to buff dolostone, shaly dolostone, and gypsum. Much of the dolostone has numerous gypsum crystal molds. Salt hopper impressions are also common. The upper Salina Group (Syracuse and Camillus) is over 60 meters in thickness in drill cores (Fig. 21; Caley 1940); however, because the Salina is such an easily eroded unit, this is represents the only exposure in southern Ontario.

Entrance to Campbell Quarry on right
Turn into drive and register; then return to vehicles and drive back to Ridgemount Road

STOP 8. CAMPBELL QUARRY
Location:Large, active quarry just west of Ridgemount Road, south of Bowen Road (Regional Road 21) and north of Garrison Road; the quarry is divided into a northern (old) portion, containing crushers and quarry buildings and an active south portion by a wall that supports Bridge Road; a tunnel under the road connects the two areas. Approximately 4 km northwest of Fort Erie and 1 km south of Ridgemount, Ontario (NTS 30L/14h, Stevensville Sheet).
Description: Campbell Quarry is the northern of two adjacent quarries operated by Ridgemount Quarries Ltd., a division of Walker Industries. This quarry contains one of the most complete sections through the Upper Silurian Bertie-Akron strata (Cooper and Plewman 1983; Figs. 12, 21). A glacially-striated surface is visible at the top of an active area of the quarry. In ascending order, the following units are exposed in the quarry faces:
Bertie Group
Fiddlers Green (Falkirk) Formation (4.5 m)- Dark gray to brown algal-laminated dolostone, weathering yellowish brown and characterized by a coarse conchoidal fracturing; large domal stromatolitic structures 2 to 6 meters in diameter separated horizontally by non-laminated, fine-grained dolostones containing eurypterids, leperditian ostracodes and small bivalves. The lowest meter contains meter scale thrombolites with Whitfieldella brachiopods.
Scajaquada Formation (1.7 m)- Unfossiliferous dark gray shales and shaly dolostone. The unit is well laminated and some bedding surfaces feature casts of salt and gypsum crystals.
Williamsville Formation (1.25 m)- Planar-laminated fine-grained dolostone, weathering light gray and characterized by a pronounced conchoidal fracture. The lower, massive half-meter bed ("Buffalo Waterlime"), exposed in the quarry floor, contains the famous Bertie eurypterid fauna typified by Eurypterus lacustris (see Clarke and Ruedemann, 1912, Copeland and Bolton, 1985).
Akron Formation (3.6 m) - Greenish-grey to light brown, fine grained, thin-,wavy-bedded burrow mottled dolostone with an irregular fracture. The Akron contains a sparse and poorly preserved fauna including corals, brachiopods, and cephalopods (Buehler and Tesmer, 1963).
The contact between the Late Silurian Akron Formation and the Lower Devonian Bois Blanc Formation, well shown near the tunnel, is sharp and shows channels of 1 to 3 meters across and up to 1 meter in depth, with glauconitic sand and gravels at their bottoms. Cracks and fissures reaching as much as 4 meters down into the top of the Akron Formation can sometimes be found and are often infilled with a well-sorted white sandstone, probably representing an erosional remnant of the Lower Devonian Oriskany Sandstone (Caley, 1940). The Devonian Bois Blanc Limestone is exposed high in the quarry wall and can be studied to better advantage in the Ridgemount Quarry to the south (see below). However, fallen blocks of cherty, fossiliferous, and heavily bioturbated Bois Blanc may be seen in the Campbell Quarry.

STOP 9. RIDGEMOUNT QUARRY
Location: Large abandoned quarry about 2 km south of Campbell Quarry on west side of Ridgemount Road and north of Highway 3; a gravel ramp road leads down into quarry from locked gates at a disused weigh station; Ridgemount, Ontario, (NTS 30L/14h, Stevensville Sheet).
Description: Because of the regional 0.5° southward dip, this quarry exposes higher strata than does the Campbell, although the two sections overlap. The Silurian-Devonian (Wallbridge) unconformity (Fig. 12) is spectacularly displayed in the southern part of the quarry and in patches of the quarry floor in the southern area. A Trypanites-bored rockground is developed on the upper surface of the Akron Dolostone; borings have been infilled with a bright green glauconitic matrix (see Kobluk et al., 1977).
The overlying Devonian Bois Blanc and Onondaga formations are exposed in the higher walls:
Bois Blanc Formation (2.5 m) - Cherty, dolomitic limestone with shale partings and containing local brachiopod coquinas and coral debris. The lower Bois Blanc contains glauconitic sandy sediments. The Bois Blanc is Early Devonian (Emsian) in age (Uyeno et al, 1982; Telford and Johnson 1984). The Bois Blanc is separated from the overlying Onondaga Limestone by a sharp, limonite-stained unconformity.
Onondaga Formation. Edgecliff Member (5-6 m) - Crinoidal and coral-rich, variably cherty wacke- and packstones and biohermal limestone. Emsian-early Eifelian (Oliver, 1976; Uyeno et al., 1982). The lowest meter consists of interbedded crinoidal grainstone and green, shaly limestone. A second unit is highly variable in thickness along the eastern quarry walls due to the local development of favositid-rugose coral bioherms, particularly well developed in the northeast corner of the quarry (see Wolosz, 1990). The bioherms show abundant colonial rugosans: Eridophyllum, Acinophyllum, and large hemispherical and ramose favositids (Fig. 22).The bioherms locally rest on a thin greenish shale with fossil debris. They are draped by a cherty wackestone which locally pinches out over the tops of the "reefs"; a thin (5-10 cm) dark gray shale bed caps the cherty interval and drapes the tops of the bioherms. The higher Edgecliff, above the bioherms, consists of crinoid rich shaly packstone with dark gray cherty nodules, The highest units consist of non-cherty crinoidal grainstones.

SatC1: STRUCTURE AND UPPER DEVONIAN STRATIGRAPHY IN THE APPALACHIAN PLATEAU OF ALLEGANY COUNTY, NEW YORK STATE, INCLUDING THE CLARENDON-LINDEN FAULT SYSTEM
Robert D. Jacobi and Gerald Smith
UB Rock Fracture Group
876NSC
SUNY at Buffalo
Buffalo, NY 14260
rdjacobi@acsu.buffalo.edu
INTRODUCTION
The Clarendon-Linden Fault System (CLF) is located in western New York, where it extends south from Lake Ontario into Allegany County (Fig. 1). The CLF has been called the "longest(?) and oldest(?) active fault system in eastern United States (Fakundiny et al., 1978a). Despite these kinds of accolades, and despite over 70 years of geological investigations (albeit sporadic) of the CLF, the CLF proved to be elusive. For example, prior to the most recent research program headed by Jacobi and Fountain (1996), the CLF had never been observed in outcrop.
The primary objective of this field trip (Fig. 2) is to examine one of the sites where the CLF does affect surface bedrock units. Other structural features that will observed on the field trip include 1) a NE-striking brittle thrust related to Alleghanian tectonics, 2) bedding restricted (intra-stratal) pencil cleavage and associated "roll-up's" of assumed Alleghanian age, and 3) fracture intensification domains (Fig. 3). Additionally, we will make several stops that illustrate the detailed Upper Devonian stratigraphy we developed during the course of the investigation (Fig.4). This stratigraphy appears to be controlled in part by motion on the CLF.

SatC1: STRUCTURE AND UPPER DEVONIAN STRATIGRAPHY IN THE APPALACHIAN PLATEAU OF ALLEGANY COUNTY, NEW YORK STATE, INCLUDING THE CLARENDON-LINDEN FAULT SYSTEM

STOP 1. The Laona waterfall,
The Laona waterfall, has been discussed in previous field trip guides (e.g., Baird and Lash, 1990). The basal sandstone of the Laona is exposed at the top of the waterfall. The importance of the Laona on our field trip is its proposed correlations. One of the proposed correlations is with the Bradford Third Sandstone (Fettke, 1938, Tesmer, 1963), and thus the Laona is a proxy for one of the most well-known, but never exposed, oil sands in the USA. A second correlation is with the Rushford Formation sandstones in northern Allegany County (Chadwick, 1923, 1936). As we shall see in stops 2 and 3, the Rushford Formation is a distinct marker unit in the upper Devonian shales and sandstones of Allegany County. Shallow drilling in northwestern Allegany County explored the Rushford as a reservoir rock. We suspect that the first oil well drilled in NYS, the McClintock #1 on Agett Rd, was probably drilled into the Rushford Formation. Oil springs in the area of the first well were most likely controlled by migration along fractures of the CLF from the Rushford sandstones, themselves a fractured reservoir in this area.

Shumla Rd, type locality of Upper Dev Shumla Sandstone.

Outside of Sinclairville,
Wells tap the Bass Island Trend, a set of Alleghanian NE-striking thrusts.

Entering Allegany Indian Reservation (of the Seneca Indians)

Passing the town of Salamanca
Named for a Spanish backer of the New York, Lake Erie and Western RR (Erie RR). This railroad was the one that Daniel Webster viewed from a rocking chair tied down to a flat car.
From Salamanca to Rt. 219 S intersection, we will pass scattered outcrops of Conneaut and Conewango Group sediments

Crossing Allegheny River

Crossing Rt. 219, last exposure of scattered outcrops

Passing Chipmunk Creek on right, location of Chipmunk oil field

Passing the Olean kame end moraines

Crossing the Allegheny River for the
last time

View of Mt. Herman and Rock City
(exposures of the Pennsylvanian Olean Conglomerate hold up the top of this mountain)

Passing the city of Olean.
Olean was a major oil trans-shipment point on the Erie Railroad, and also the site of refineries. The last refinery to operate was the Socony-Vacuum, which quit in the 1950's.
Dresser-Rand (to the right) still constructs compressors and gas turbines for the oil 71.4 0 patch. In the 1960's, it accounted for 2/3's of all such equipment built worldwide.

Outcrop on left, of something

N-trending steep hill on left.
The Cuba Indian Oil-Spring Reservation, the first reported occurrence of petroleum in North America, is located in the valley west of the hill. This oil spring is on strike with the Rawson Valley CLF fault.

Sharp-based packet of storm-generated sandstones
Sharp-based packet of storm-generated sandstones outcrop on left, equivalent to the Upper Devonian Cuba Sandstone.

Eastern Continental Divide

Friendship Oil patch operators built mansions in this town.
Now the home of Friendship cottage cheese.

Enter TravelPort-Buckhorn-Mobil to regroup and refuel

Outcrop of the Rushford Fm on left
Outcrop of the Rushford Fm on left displaying the contact between sandstone and overlying transgressive lag

Outcrop of the Rushford Fm on left
Outcrop of the Rushford Fm on left displaying disrupted bedding, roll ups, folded units and pencil cleavage related to an Alleghanian NE-striking ramping thrust

Optional Stop, Genesee River, by Transit Bridge.
Optional Stop, park in clearing before bridge, walk down to the Genesee River via path- outcrop of the Rushford Fm.
This optional stop displays the Rushford Formation exposed by the river's edge. Shoreface sedimentary structures common to the Rushford Formation and soft sediment deformation can both be observed here. Outcrop of the Rushford at the river level is very similar to the Rushford exposed along Rt. 19 to the South at mile 101.75 of the field trip. The elevation difference is caused either by a NW-striking fault or the thrust zone at mile 101.77 of the field trip.

Gully on left contains outcrop of the Rushford Fm.

Roadcut on left of the Rushford Fm.

20 ft beyond the road to the left is old Rushford quarry described by James Hall in 1843

STOP 2. White Creek.
This stop consists of two separate outcrops that illustrate the characteristics of both the CLF faults and the sandstones of the Rushford Formation. We will examine first the downstream outcrop (Stop 2A), where the Lower Rushford sandstone packet outcrops in three stacked lowstand shoreface sequences; each shoreface sequence capped by a transgressive lag deposit (Smith and Jacobi, 1996,1998a, 1999) (Fig. 4). Here the master fractures strike approximately north (Fig. 5A)--an anomaly compared to the usual NW and NE striking fractures found in western NYS (e.g. Engelder and Geiser, 1980). As shown in Figure 5B, the spacing of the N-striking fractures here is quite close, compared to nearby regions that have essentially no N-striking fractures. That the N-striking fractures are relatively closely spaced, and are masters, suggest that a N-striking FID passes through the outcrop at White Creek.
Site 2A: White Creek Rd, by Little John Rd. bridge. North of the bridge is a large exposure of the three-shoreface sequences that comprise the lower sandstone packet of the Rushford Formation. At the northernmost exposure of the outcrop, the 1st shoreface sequence forms the lowest step in the series of small falls that comprise outcrop (Fig. 6B, C). The top bed is a fossiliferous, medium to coarse-grained sandstone that typifies the transgressive lags that occur over the shoreface sequences in lower sandstone packet. Overlying the 1st shoreface is a thick interbedded section that is well exposed on the east cliff exposure. Soft-sediment deformation, primarily ball-and-pillow structures, are well exhibited in the sandstone beds beneath the 2nd shoreface sequence. The 2nd shoreface sequence displays planer laminated beds typical of the shoreface sequence but more noticeably contains a large olistrolith of sandstone surround by a debris flow indicative of a syndepositional mass flow. The top of the 2nd shoreface sequence occurs near the main falls. This sandstone displays small dunes (amplitude- ˜0.5m, wavelength ˜2.0 m) with symmetrical ripples. The 3rd sandstone sequence forms the upper part of the cascade; the most noticeable feature is the transgressive lag that caps the falls. This lag deposit contains large clasts of white, cloudy quartz as well as numerous brachiopod shell fragments and large red silt clasts. The underlying sandstone contains Rhizocorallium, Arenicolites and Thalassinoides, typical of a Glossifungites firmground. Overlying the 3rd shoreface sequence is the thick interbedded sequence that separates the lower sandstone packet from the upper sandstone packet (Fig. 6B,C).
Below the waterfall, the vertical and overhanging outcrop on the east side of the creek displays a characteristic of FIDs. Some of the N-striking fractures exhibit small stratigraphic throw (on the order of a few cm). These step faults may be a small scale example of the step faults that are observed on seismic lines as "folds" or sharp monoclines; i.e., the amount of offset on any one fault is below the resolution of the seismic line. These small scale faults, with a down-on-the-west sense of motion, are consistent with the larger scale fault inferred from the juxtaposition of stops 2A and 2B (Fig. 6B, C).
In the creek bed upstream from the bridge, as well as along the east wall of the creek near the bridge, several bedding-restricted (intra-stratal) zones of pencil cleavage outcrop. Elsewhere in western NYS pencil cleavage has been ascribed to bedding parallel thrusts of Alleghanian age, primarily because the cleavage usually strikes NE, parallel to the Alleghanian fold axes and crinoid strain ellipsoids (Engelder and Geiser, 1979; Jacobi and Zhao, 1996a,b). Here the cleavage has several trends, including NNE, NE and approximately NS, parallel to the CLF fractures. In a few localities it is possible to observe the N30E trend curving into parallelism with the approximately N-S. We suggest that the pencil cleavage does indicate early bedding-parallel shear (bedding thrusts) that has an Alleghanian age; the N-striking cleavages suggest that the CLF was also active at this time also and locally controlled the generation of the pencil cleavage. Throughout the outcrop south of the bridge N-striking master fractures clearly cross the pencil cleavage zones, indicating that at least the last generation of N-striking master fractures post-dated the generation of the pencil cleavage.
Spectacular boudined sandstone blocks (roll-ups) occur in some of the pencil cleavage zones. Some sandstone rollups display dewatering phenomena, such as hairline sandstone dikes. Apparently, the dewatering occurred as the deformation of the block progressed, as the blocks display both brittle (small step faults) and ductile behavior (the primary folding, or roll-up). The question remains whether the roll ups are solely the result of deformation associated with the generation of pencil cleavage, or whether they indicate sediment slides (such as the one below the sandstones) that were then deformed further during generation of the pencil cleavage and bedding-parallel shear. Throughout Allegany County, we have found a strong association between roll-ups and pencil cleavage (Jacobi and Zhao, 1996a,b), and believe that many of the roll up zones did originate during bedding-parallel shear. However, the zone of roll-ups exposed farthest upstream at Stop 2A appears to have a "bumpy" upper contact with local depressions that were filled in by the overlying unit. In this case, the roll-ups may have originated as a sediment slide and then been further deformed during generation of the pencil cleavage.
Near the south end of the outcrop, in the area of pencil cleavage, N-striking master fractures with anastomosing abutting fractures have a raised weathering profile, and indicate either the injection of sand ("neptunian dikes") or fluids that resulted in a more resistant unit.
Stop 2B, about 0.4 km upstream from Stop 2A (0.25 mi south of Little John Bridge - it is easiest to walk along the road, then head down into the creek to the waterfall), appears to exhibit a very similar stratigraphy to that exposed at Stop 2A. The same, major depositional elements are present at both outcrops (Fig. 6B). At both outcrops, a sediment slide without any cleavage development is found below the thick sandstone packet. The sandstone packet at the Stop 2B waterfall itself is similar to the sandstones of the upper part of the 2nd shoreface sequence and all of the 3rd shoreface sequence at Stop 2A. Although the Stop 2B outcrop does not have a thick transgressive lag deposit similar to Stop 2A, a thin coquinite is observed at the top of the 3rd shoreface sequence and on top of the 2nd shoreface sequence, large cloudy quartz pebbles can be observed (Fig. 6B). Finally, both outcrops have zones of pencil cleavage above the sandstones.
The question is: are the two sequences at stops 2A and 2B the same, with a N-striking fault separating the two outcrops, or are the repetitions merely coincidental repetitions of depositional environment, with a stratigraphic succession accounting for Stop 2A below Stop 2B. If the two outcrops do indicate a fault, then the offset between the outcrop at Stop 2A and the repeated section at Stop 2B is approximately 11.6 m (~38ft), down-on-the-west (Fig. 6B, C). We suggest that the repetition is tectonic for several reasons: 1) elsewhere, the Rushford does not have two sets of similarly repeated units, 2) the N-striking fractures at both sites are anomalous, and provide a warning that N-striking structures may be in the area, 3) the small step faults at the lower wall of Stop 2A are consistent with the sense of motion necessary to account for the repetition of units.

For road access to Caneadea Gorge, ask permission at house on left

STOP 3. Caneadea Gorge overlook, east of Rushford Lake.
The type section for Caneadea Formation as defined by Chadwick (1933) contains exposures of three of the four informal members of the Caneadea Formation (Gorge Dolomitic, Higgins, and the West Lake members). The Rushford Formation outcrops beneath the overlook, 4-5 m from the top of the cliff (Fig. 7). There are two ways to gain access to Caneadea Gorge: one is located at the Rushford Dam picnic area where a small, steep path leads from the top of the cliff to the creek. Old quarries to the left of the path expose the thick Rushford sandstones. The 2nd is an access road, near a small farmhouse on this road at the base of the hill east of the overlook. There is a locked gate, but access can be obtained by asking permission at the farmhouse.

STOP 4. Lunch stop at the Caneadea dam.
Beyond the fence is the Caneadea Dam and Rushford Lake
Old photographs of the construction of the Rushford Dam show the north wall of the gorge (the side we are on) devoid of trees, and show quarries of the Rushford sandstones. These quarries can still be found along the wall, and provide good illustrations of the thick Rushford sandstones here. By the dam, and around the eastern end o fRushford Lake, is the type exposure of the Rushford Formation as defined by Luther (1902), although close, hands-on access to these outcrops can be difficult depending on the lake level. The sandstones of the Rushford Formation are much thinner here than at White Creek; the upper and lower sandstone packets and the interbedded section are condensed. Unlike the White Creek outcrop, the lower sandstone packet does not contain transgressive lag deposits, but does contain the three shoreface sequences and contains cloudy quartz clasts in the matrix of the upper shoreface deposits.
When the water level is lowered in the Fall, on the south gorge wall west of the dam can be seen a series of N-striking, east-dipping, closely-spaced step faults, each with minor offset (on the order of a few cm). These small faults are consistent with well logs that indicate a down-on-the-west fault just west of here. Other indicators of the fault include 1) the N-striking valley (lineament) where the wells indicate a fault must be, and 2) surface stratigraphy that suggests about 15.25 m of offset across this fault.

Optional Stop, Hillcrest Rd, Rushford Formation roadcut.
Turn south on County Rt. 49 (Hillcrest Rd), from Rt. 243. Thick laminated sandstone ( ˜3 meters thick) occurs on either side of the road, where Rt. 49 starts to climb the hill. The road also begins to curve at this location, so care is needed. There is a wide shoulder on the western side of the road. The western side displays the contact between Caneadea and Rushford formations, while the fracture controlled exposure on the eastern side gives an excellent view of the planar laminations and small, white, cloudy quartz clasts incorporated in fine-grained sandstone matrix.

View of NE-trending valley
View of NE-trending valley, with inferred Alleghanian thrust fault with 80 ft of offset.

Passing through the bustling metropolis of Higgins

Outcrop in creek near bridge
Outcrop in creek near bridge, typically buried by gravel. Pencil cleavage here with sandstone roll-ups and sandstone dikes

Defined type section of the Higgins Mbr. of the Caneadea Fm.

House on left is sheathed with rippled sandstone from Sixtown Creek

STOP 5. Sixtown Creek by Creek Rd.
Ask permission for creek access from house on the left
NE-striking Alleghanian fault zone. This stop is located in a large NE-trending valley, which displays a NE-striking fault and fold system. At the intersection of Creek and Weaver roads is a small bridge that crosses Sixtown Creek; the outcrop starts approximately 200 m upstream (west) of the bridge. Where we shall enter is farther west, towards the middle of the outcrop. The outcrop is comprised entirely of the Caneadea Formation, with the type exposures for the Higgins Member (informal). The lithology is interbedded light to medium gray silty shales, shaly siltstones, and typically thin (1- 6 cm) micaceous, fine-grained sandstones. The outcrop displays a coarsening upward sequence, with thick sandstone (20-50 cm) near the top of the Higgins Member. The typically linguoid ripples found on exposed sandstone beds as well as numerous furrows (guttercasts) may indicate a storm influence. Soft sediment deformation is present, but becomes abundant towards the upstream end of the outcrop, at the village of Higgins where large ball-and-pillow structures (1-4 m in length) are commonly observed in outcrop. These ball and pillows are encased in a strongly pencil cleaved shale that has thin sandstone dikes.
A NE-striking, southeast-directed brittle thrust fault is observed at the sharp bend in the creek on the northern wall of the cliff (Fig. 8). Here the thrust has a fault zone comprised of fault gouge, fault breccia and drag folds. Open folds upstream from the thrust complete the deformation structures at this stop. We suggest that the NE-tending valley in which these structural features occur is related to an Alleghanian thrust that is represented by the structural features seen here.

Finger Lakes Trail to the right
Exposure of the Hume Fm and Caneadea Fm in creek, with pavement displaying NE-striking fractures, consistent with a NE-striking thrust along the valley

STOP 6. Wiscoy Creek at Mills-Mills where Mills-Mills Rd. crosses Wiscoy Creek.
This is the upstream end of a fairly continuous outcrop that extends down Wiscoy Creek to the RG&E powerhouse that is located on the west side of Wiscoy Creek (Fig. 9). Exposures of the type section of the Hume Formation as defined by Pepper and deWitt (1951) are along the banks of the stream near the dam and along the roads near the dam. The base of the Hume Formation is obscured by the dam at Mills-Mills, but the roadcuts on either side display the black silty shale, with large (50-120 cm) carbonate concretions. The Hume displays a regional thickening that is coincident with the CLF (Fig. 10), suggesting that CLF fault activity controlled the shape of the depositional basin in which the Hume was deposited.
Below the bridge is our defined type section of the Mills-Mills Formation (informal) that is correlative to the Canaseraga Formation. Near the downstream (northeast) end of the outcrop at the top of the waterfall near the powerhouse the contact between the Mills-Mills Formation and the underlying South Wales Formation is displayed (Fig. 9). At the waterfall thick (20-40 cm), fine-grained sandstone beds of the Mills-Mills Formation form the caprock. The exposure of the Mills-Mills continues upstream with the sandstones forming small cascades to the dam at Mills-Mills.
The sandstones forming the Mills-Mills are turbiditic. The shales and siltstones grade from dark gray to black at the top of the formation. The underlying South Wales is comprised of interbedded light-dark gray silty shales and shaly siltstones, interbedded with thin, fine-grained sandstones. The lowest exposure of the South Wales Formation is a thick (˜1 m) amalgamated packet of calcareous, fine-grained sandstones. Fractures at Mills-Mills trend NE (64°) and NW (316°); the NE-striking fractures both abut and intersect the NW-striking fractures. In some areas the NE-striking fractures are relatively closely spaced, consistent with a NE-striking FID in the general region.

STOP 7. Wiscoy Falls on Wiscoy Creek at the village of Wiscoy.
Type locality for the Wiscoy Fm.
From the bridge crossing Wiscoy Creek, 2 of the 3 major falls comprising Wiscoy Falls can be seen. Below the bridge, beds (10- 15cm thick) of dolomitic sandstones form large shelves, while the calcareous shaly siltstones and calcareous silty shales form small cascades. This is the type exposure of the Wiscoy Formation as defined by Clarke (1898). Upstream, by the dam, is the contact between the Wiscoy Formation and the Dunkirk Formation, which is also the transition between the West Falls and Canadaway groups, as well as the Famennian-Frasnian boundary (Fig. 9). Trace fossils are abundant on the surfaces of the sandstones, with large Teichichnus commonly observed; Skolithos and Arenicolites can be seen in cross-section.
Fractures on the pavement above the first major waterfall trend NW and NE, with NW fractures consistently the master. There is no anomalous spacing of fractures in the outcrop, and so no FID has been proposed for this region. Note that, as is typical for much of the county, no NS-striking fractures are present. Stepping, NW-striking fractures suggest a counter-clockwise stress rotation during the Alleghanian generation of the NW-striking fractures (Zhao and Jacobi, 1997). The patterns of fracturing on this pavement were shown in Figure 4 of Zhao and Jacobi (1997).

Ward Berry's farm
Passing intersection with Hardy Rd., to the right is Ward Berry's farm and location of gas blows resulting from the Saguenay earthquake in 1989

Passing through Bliss, kind of Zen, huh?

SatD: ENCOUNTERS OF NATURAL, FISCAL AND LEGAL KINDS ON THE COAST OF THE GREAT LAKE ERIE - DEALING WITH HARBOR CONTROVERSY AT NORTH EAST AND HARBORCREEK- SHADES BEACH, PA AND REVISITING THE COST EFFECTIVENESS OF THE $23 MILLION DOLLAR PRESQUE ISLE EROSION CONTROL PROJECT AT ERIE, PA
M. Raymond Buyce
Department of Geology
Mercyhurst College
Erie, PA 16546
Coastal erosion and deposition effects caused by human generated structures is a key theme of this trip. Although we might assume that the impact of coastal processes on the general public of the United States is restricted to oceanic shorelines we will see that construction on Great Lakes shorelines is fraught with the same difficulties as those faced on the Atlantic and Pacific Oceans. Thus inland colleges with access to Great Lakes shorelines have established Coastal Geology programs that offer hands-on training to their students and advice to local, State, and Federal Government agencies responsible for coastal zone management.
Both erosion and deposition patterns altered by hard structures built on the coast are problematic to those of us who live, work and play there. Proceeding from east to west along the shoreline we will first visit the harbor at North East, P A that is in the latter stages of litigation against those responsible for its construction and management. Our next stop will be at the site of the proposed harbor and detached breakwater at Shades Beach in Harborcreek P A where a federal and state Coastal Zone Management study is underway to avoid such legal complications. And, finally we will revisit the 55 offshore breakwaters of the Presque Isle Erosion Control Project at the peninsula enclosing the harbor at Erie, P A US Army Corps of Engineers efforts to stabilize the sand spit and thereby to protect the harbor by construction of on-shore hard structures such as groins stretches back to 1828. In spite of these efforts, an average of well over $1 million worth of sand has had to be added to the beaches each year since 1956 (annual nourishment). Completed in 1992, the cost-effectiveness of the latest $23.8 million US Army Corps ofEngineers' project will be judged, at least in part, on achieving a major reduction in this annual sand nourishment expenditure. Less sand from off-site has been required subsequent to construction partially due to the newly developed possibility of recycling sand deposited behind some of the breakwaters. However, to date a goal of a 75% reduction in replenishment costs has been elusive. With La.Ke Erie at its lowest level in decades this year, a new problem has emerged. ''Excessive" deposits at the end of the spit threatened to close off a very popular beach (Beach 11) from the open lake rendering it useless due to stagnation, excessive weed growth, and potential pollution. Dredging of 10's of thousands of cubic yards of sand has been required to preserve the recreational resource. The good news is that the sand is being used as a lower cost source of nourishment up drift (to the west) on the peninsula.
The first of our three stops on Presque Isle will give us the opportunity to see how variable the effect of the offshore breakwaters has been on beach erosion and deposition. Near the lighthouse erosion has continued to be severe despite the presence of breakwaters offshore. Immediately downdrift (to the east), "excessive" deposition results in the annual connection of the beach to a breakwater forming a tombolo. The proximity of the two areas will highlight an Sat. 01 unexpected benefit of the project; harvesting of the unwanted sand deposits from the tombolo serves as a low cost source of sand which is recycled as nourishment for the nearby area of erosion. We will ascend the lighthouse in small groups to obtain an aerial view of the situation. Our second stop will be at Beach 10 and Gull Point where the nourishment sand from the Beach 11 spit dredging and recycling operation is being placed. The easternmost of the 55 offshore breakwater sequence and three additional earlier constructed prototype breakwaters will also be visible. Not surprisingly, it is the area immediately downdrift from the last of these erosion control structures that was designated as most in need for receiving the dredged sand. The fate of the nourishment sand over the next several months will be monitored by students as part of a undergraduate coastal studies GIS project. The data and project report will be provided to Presque Isle State Park management and to the US Army Corps of Engineers. The final stop of the trip will be at the Beach 11 site of the sand spit which was dredged. The dredging and nourishment project is due for completion in mid-September 1999 so all activity should be over by the time of our visit.

SatD: ENCOUNTERS OF NATURAL, FISCAL AND LEGAL KINDS ON THE COAST OF THE GREAT LAKE ERIE - DEALING WITH HARBOR CONTROVERSY AT NORTH EAST AND HARBORCREEK- SHADES BEACH, PA AND REVISITING THE COST EFFECTIVENESS OF THE $23 MILLION DOLLAR PRESQUE ISLE EROSION CONTROL PROJECT AT ERIE, PA

Mercyhurst College - North East Campus

STOP 1. NORTH EAST MARINA, NORTH EAST, PA
Stop at office. Proceed to bottom of hill and park opposite marina. Proceed downdrift (east) along shore. Notice nourished beach width, bluff, and any erosion control structures. Return to harbor continuing to updrift (west) side noticing partially-harvested beach width, bluff, and any erosion control structures.
North East Marina (formerly Safe Harbor Marina) was constructed on the southeast shore of Lake Erie at North East, Pennsylvania in 1989-1990 to provide access to the recreational use of the lake and shelter for boaters. In fact, for boaters caught in a storm, it is the only shelter between Barcelona, New York and Erie, Pennsylvania. Prior to construction, Buyce and Kent Taylor applied for a grant from Coastal Zone Management of NOAA to provide a base line study of the littoral drift system for use in formulating requirements for construction and management of the facility. The study was not funded.
A private corporation, under lease from the Pennsylvania Fish and Boat Commission, obtained the necessary permits from the US Army Corps of Engineers and the Pennsylvania Department of Environmental Resources and constructed the marina. The regulating agencies clearly anticipated that harbor construction would interrupt the normal littoral drift pattern because ongoing nourishment was required by the permits to prevent starvation of the downdrift beaches. The facility managers made only token attempts at nourishment and, because the preconstruction littoral drift volume was unknown due to the lack of a baseline study, it was difficult to specify what would be an adequate annual volume of nourishment. Meanwhile homeowners downdrift (on the east side) instituted lawsuits against everyone involved with the marina as they saw sand accumulating on the west side of the harbor and felt that their beaches were narrowing and bluff erosion potential was being exacerbated in front of their homes.
Caving in to the dual pressures of agencies threatening to revoke permits and to lawsuits the corporation went bankrupt in 1993 and the facility and its problems reverted to the Pennsylvania Fish and Boat Commission who immediately instituted a substantial nourishment program for downdrift beaches. Realizing that, in a litigious environment, an adequate amount of annual nourishment would be difficult to establish to the satisfaction of all concerned, the Fish and Boat Commission wanted objective scientific data. They finally funded a study of the littoral drift system (Taylor and Buyce, 1994 and Buyce and Taylor, 1998).
A major objective of the study was to determine exactly how much and what size sediment would have reached the downdrift beaches each year if the harbor were not constructed. After establishing that no significant volume of sediment was being lost offshore or continuing to reach the downdrift beaches (bypassing the marina) the task was to measure the annual volume of sediment accumulating updrift from the west wall of the harbor and determine its textural characteristics. As beach width is assumed to be inversely related to potential for bluff erosion potential, there was also a need to determine if construction of the marina had, in fact, resulted in the narrowing of downdrift beaches. The examination of historic photographs from 1986 was used to compare to modern beach widths.
The extensive nature of the study is evident below in extracts from Buyce and Taylor, 1998.

STOP 2. SHADESBEACH, HARBORCREEK, PENNSYLVANIA
Park in lot at foot of first hill. Walk to shore. Observe site of new harbor and offshore breakwater. Notice bedrock of the Northeast Shale (and siltstone) extending well above the lake level protecting the bluff from wave erosion. Glacial till (unconsolidated boulders, sand, silt and clay) extends to the top of the bluff.
This is the proposed site for construction of both a harbor and a detached breakwater up drift (to the west). The harbor will be similar to the one at North East and the detached breakwater will be similar to those we will see at Presque Isle (Figure 5). To avoid legal complications such as those at North East Marina a federal and state Coastal Zone Management study has been funded and is underway to provide pre-construction baseline data. The coastal marine contractors selected for the study will need to determine the natural, pre-construction, conditions during the course of an ice-free year. Pre-construction conditions include both the shape of the exposed and submerged beach and the dynamics of the littoral drift processes. They will document the configuration of the exposed beach and the nearshore bathymetry and its natural seasonal variability. That, along with the interpretation of the dynamics of waves, currents and sediment transport in the area could be used to predict the effects of the off-shore construction improvements planned as part of the overall Shades Beach Park Development Project. The data and interpretations will be used to predict adverse coastal effects including impacts to downdrift (eastern) bluff areas which may occur in the short and long terms and considering the effects of fluctuating lake levels.
It would be obvious to draw heavily on the lessons learned nearby on the Lake Erie shore at North East (for the harbor) and at Presque Isle (for the offshore breakwater). Significant differences between the Shades Beach site and the others would have to be taken into account. Obviously site-specific differences will have to be considered. Examples of the differences include (1) At Presque Isle there is far more sediment in the system to accrete wide beaches behind offshore breakwaters, (2) Bedrock of the Northeast Shale which outcrops below lake level at North East and is only seen offshore is present a meter or more above lake level at Shades Beach providing the bluff protection from wave erosion here, and (3) At Shades Beach Eightmile Creek brings sediment into the littoral zone immediately downdrift from the proposed harbor whereas, at North East, the nearest input downdrift is from Twentymile Creek 900 m (2953 ft) downdrift.
The geomorphic development of the site is interesting and relevant. Discussed by Schooler (1974) and expanded upon by Delano (in Thomas et al., 1987), the following exceRpt is from Delano (p 74-75): This township park takes advantage of a rare low flat valley with lake access. The reason for the existence of the flat area which the park occupies is evident from the topographic map of the area (Figure 44) and Figure 45 (Figures 6 and 7 respectively herein) Eightmile Creek, which now enters the lake just east of the access from the park to the lake shore, formerly occupied this valley. Lake erosion and bluff recession caused the shore line to retreat until it intersected a northward meander loop in the entrenched stream valley. The lake effectively captured the stream, leaving the lower valley occupied by a severely underfit stream (and the parking lot -author). Eightmile Creek falls approximately 12 m (40 ft) from the abandoned channel channel upstream of the mouth. This example of piracy is evidence that erosion and bluff recession along the Lake Erie shore are not recent developments ....
Delano goes on to consider why bluffs are relatively stable here (p75-77): ... Two possible explanations for this are (1) the bedrock ledge protects the bluffs from the erosion, and (2) the isolation of the bluff section by the abandoned stream channel limits the source area for groundwater, and the resulting small amount of seepage out of the slope face is a factor in the apparent increased stability of the bluff. Both factors are probably important, but the relative importance of each is unknown. Several features to notice from the beach and from the bluff overlook accessible from a trail beginning in the parking lot are: (1) The beach is very coarse grained with abundant gravel and it extends only a short distance out from the shore line before it gives way to extensive exposed bedrock ledges of Northeast shale (actually an interbedded shale and siltstone facies), (2) The protective ledge extend well above lake level and is overlain by unconsolidated glacial diamict (very poorly sorted boulders, sand, silt and clay) which extends to the top of the bluff, and (3) the poor condition of the concrete remnants of shore line structures provides evidence of the power of Lake Erie to destroy inadequately engineered coastal structures, especially in time of high lake levels.

Mount Saint Benedict Monastery

Presque Isle Bay (Erie Harbor)
Presque Isle Bay (Erie Harbor) enclosed by Presque Isle sand spit, locally called "The Peninsula"

Stull Interpretive Center, on left.
Presque Isle Bay (Erie Harbor) and City of Erie, on right.

Cookhouse, Waterworks (previous water supply for City of Erie)

Lighthouse

STOP 3. PRESQUE ISLE - LIGHTHOUSE BEACH AREA
The first of our three stops on Presque Isle will give us the opportunity to see the how variable the effect of the offshore breakwaters has been on beach erosion and deposition. Near the lighthouse erosion has continued to be severe despite the presence of breakwaters offshore and immediately downdrift (to the east) "excessive" deposition results in the annual connection of the beach to a breakwater forming a tombolo. The proximity of the two areas will highlight an unexpected benefit of the project: harvesting of the unwanted sand deposits from the tombolo serves as a low cost source of sand which is recycled as nourishment for the nearby area of erosion. We will ascend the lighthouse in small groups to obtain an aerial view of the situation. A study of one cycle of tombolo growth was completed by undergraduates and reported to the northeastern Section of the GSA (Wilson et al., 1997).
Small groups (12 or less) will ascend lighthouse for aerial view of lighthouse beaches and tombolo area. The beaches immediately downdrift (east) of the lighthouse groin behind breakwaters 45, 46, and 47 remain erosional in spite of the new structures. Excessive deposition begins further downdrift culminating in the annual formation of a connection of the beach to breakwater 49 each fall (a tombolo).
Walk beaches from lighthouse groin east past breakwater 45 to beach opposite breakwater 49 (site of tombolo growth)
LUNCH
Participate in digging beach trench to expose stratigraphy developed during growth of tombolo.

STOP 4. PRESQUE ISLE - BEACH NO. 10 AND GULL POINT
Enter parking lot beyond BathHouse. From beach observe to the west, the east end of the sequence of 55 offshore breakwaters with the three prototype breakwaters extending beyond to this location. Nourishment sand widens the beach here and evidence of previous erosion is evident behind the beach downdrift (to the east).
Our second stop on Presque Isle will be in the area where the nourishment sand from the spit dredging and recycling operation is being placed. The easternmost of the 55 offshore breakwater sequence and three additional earlier constructed prototype breakwaters are visible updrift (to the west). To the east is the environmentally sensitive area called Gull Point which is a bird sanctuary and has restricted access. Not surprisingly, it is this area immediately down-drift from the last of these erosion control structures that was designated as most in need for receiving the dredged sand. The fate of the nourishment sand over the next several months will be monitored by students as part of a undergraduate coastal studies GIS project. The data and project report will be provided to Presque Isle State Park management and to the US Army Corps of Engineers.

STOP 5. PRESQUE ISLE - BEACH N0.11 AND THOMPSON BAY
Observe Gull Point and Thompson Bay. Note site of spit deposition that had to be removed to prevent the closing off of Beach 11 from the open waters of the Lake Erie.
The final stop on Presque Isle and of the trip will be at Beach 11, the site of the sand spit which was dredged. Beach 11 is on the southwest shore of Thompson Bay which is bordered on the northeast by Gull Point and opens onto Lake Erie to the southeast. The sand spit developed on the end of Gull Point and began enclosing Thompson Bay from the north. These "excessive" deposits were coincident with very low lake levels. Ultimately the spit detached from Gull point and attached to the eastern end of Beach 11 nearly enclosing the bay (see Figures 12 and 13 from the US Army Corps ofEngineers report, (1999).The effects of nearly separating Beach 11 from the open waters of Lake Erie were stagnation, abundant weed growth and threat of frequent beach closing due to pollution. The necessary studies were done to obtain permits and dredging began in the summer of 1999. The dredging and nourishment project is due for completion in mid-September 1999 so all activity should be over by the time of our visit. We will have little to see here, having arrived after the fact but can at least visualize the situation facing the park management. The debate was heated concerning the option of allowing the "natural" processes to proceed. The fact that the Presque Isle has been a heavily managed and, at least partially, an "unnatural" system since at least 1828 apparently won out.

Perry Monument and ferry dock.
Presque Isle Bay (Erie Harbor) on left. Lagoons and dune ridges, right.

SatE: QUATERNARY GEOLOGY AND WATER SUPPLY ISSUES
Michael P. Wilson
Geosciences Department
SUNY College at Fredonia
Fredonia, NY 14063
William T. Boria
Division of Environmental Health Services
Chautauqua County Department of Health
Clothier Building
Mayville, NY 14757
Scope
While specialists in water resources have always been aware of the connection between recent geologic sediments and water supply issues, concerns have heightened during the past 15 years. Across the nation, Source Water Assessment Programs (SWAP), Wellhead Protection Programs (WHPP), new turbidity standards for drinking water, etc., are responses to outbreaks of giardiasis, cryptosporiodosis, and other concerns such as viruses as hitch-hikers on colloidal particles and the inability of traditional chlorination to treat these parasites. SWAP and WHPP also counter concerns for landfills, outfalls, agricultural runoff, and other point or non-point source contamination.
During stops 1, 2, and 3 (Figure 1) on this trip, we will pay particular attention to SWAP and WHPP issues at the recently renovated Village of Forestville Hall Springs and the long occupied Village of Sinclairville well field. This guidebook article particularly zeros-in on aquifer characterization and relationships to source areas, natural filtration of microparticulates and associated phenomena such as dilution.
Stops 1 through 5 (Figure 1) aid in understanding water well drilling successes and failures. Public and private water wells north of the St. Lawrence-Mississippi drainage divide in Chautauqua County have had low productivity. While gravel deposits and sometimes the fractured top of bedrock have moderate to high hydraulic conductivities, these zones north of the drainage divide are typically poorly recharged due to extensive confinement. Confinement relates not only to shifts in ice marginal environments but also to melt-out of underlying ice which yielded structural failure of the sediment masses and consequent abrupt changes in sediment hydraulic conductivities. The sediments exposed in cross-section in gully walls and landslide blocks, and indicated by cores, help to visualize the situation (Stop 5). Also, for those interested, the Sunday trip (this guidebook) visits a buried valley exposure with abrupt changes in hydraulic conductivities.
Turbidity sources, effects and human responses regarding drinking water from reservoirs and stream diversions are especially covered in Stops 5 to 7 (Figure 1). One of the nastier problems locally is the loss of reservoir capacity, in addition to upgrading filter plants. Which reservoir receives high sediment loads depends partly on reservoir design and partly on subtle glacial features such as end moraine control of watershed boundaries or stratigraphic control of erosive seepage or landslides.
Setting
Figure 2 is an index map for Chautauqua County municipal water supplies. Chautauqua Institute uses a surface water source, Chautauqua Lake. Otherwise, supplies north of the St. Lawrence-Mississippi drainage divide are surface waters and sources to the south are groundwaters. While the Forestville spring collectors (Stop 1) are north of the Mississippi River divide, the spring source waters (Stop 2) are south, as are Forestville's wells. With the exception of Cherry Creek's springs (fractured top of bedrock), all the groundwater sources are sandy gravels. Surface sources (north of the divide) are small reservoirs, with Westfield's Minton Reservoir supplemented by partial diversion of Chautauqua Creek. The City of Dunkirk draws from Lake Erie, and beginning in the 1990s, the Village of Silver Creek abandoned its reservoirs and connected to the Erie County, New York, Water Authority (Lake Erie). Most of the reservoirs have been plagued with high turbidities and excessive sedimentation.
WHP areas for municipal supplies are shown in Figure 2. The extensive primary protection areas that lie between Sinclairville (Stop 3) and Jamestown are the fan-delta deposits on the margins of Cassadaga Creek valley. These alluvial fan and delta gravels and sands interfinger with a continuous 20-foot thick gravel under an extensive 100 foot thick silt. This confined gravel aquifer is known as the Jamestown Aquifer (Crain 1966). Streams flowing off the uplands lose water into their beds as they cross the fan-delta gravel deposits which then recharge the aquifer. The City of Jamestown is supplied by this aquifer and the Village of Sinclairville wellfield (Stop 3) lies in one of the fan-delta deposits.
The northern portion of Chautauqua County borders Lake Erie and contains the Lake Erie Plain. The lake plain has very low relief and is about 2 miles wide to the southwest and 5 miles wide to the northeast, typically extending a mile south of Rt. 20 (Figure 1). The lake plain and plateau are separated by the Portage Escarpment (also called the Allegheny Escarpment). The name Portage comes from attempts by the French army in the 1750s to establish a portage over the escarpment in order to link a canoe route between the eastern Great Lakes and their fortifications at Pittsburgh. Today, reservoir watersheds occupy the steep escarpment ravines (Stops 5 to 7). The drainage divide between the escarpment ravine headwaters and the southerly draining Mississippi headwaters is known as the Lake Escarpment Moraines (Muller, 1963). These glacial end moraines are thought equivalent to the Valley Heads Moraines to the east (Muller, 1963; Muller and Calkin, 1993). The Forestville Springs form by water percolating through outwash south of the Lake Escarpment Moraines and draining northward back under the moraines and out the escarpment face.

SatE: QUATERNARY GEOLOGY AND WATER SUPPLY ISSUES

Village of Fredonia lies mostly on Glacial Lake Warren shoreline
The village of Fredonia lies mostly on Glacial Lake Warren shoreline and Canadaway Creek delta and terrace sand and graveL

Cross Glacial Lake Whittlesey shoreline.
We will drive slowly in this area, possibly stopping but not exiting vehicles, in order to regroup vehicles. At mile 5.1 see "beach ridge" through the front and right vehicle windows approx. 1500 feet away. Cross the "beach ridge" at 5.4 miles. At 7.5 miles, view left is Lake Erie and the Canadian shoreline ( 40 to 50 miles weather permitting).

STOP 1. Hall Springs, Village of Forestville.
Park on side of Shaw Road. We will walk eastward on the gravel entry road for about 100 meters.

STOP 2. Brief look at Hall Spring source water area.
Park on side of Putnam Road.
A water well drilled near the intersection of Putnam Rd. and Route 83 penetrated 324 feet of sediments without encountering bedrock. Depth to bedrock near this road intersection was estimated at 450 ft using a high-precision gravity survey.

STOP 3. Village of Sinclairville wellfield.

Cassadaga Water Works (wells) and maintenance buildings.
Cassadaga Lakes are on the right (north) side of the road. The lakes are kettle lakes between the Lake Escarpment Moraines to the north and the Lavery Moraine to the south. Rt. 58 that we are traveling is on outwash between the moraines. If the Lavery Moraine dates at 16,000 BP and the Lake Escarpment dates at 14,000 BP, were the kettles formed from Lavery ice buried by Lake Escarpment outwash?

Dean Road passes through a small Amish community.
A large Amish community is found about 30 miles to the east in the Conewango Valley.

STOP 4. Turn Right (east) into Luensman Overview Park.
Lunch and rest stop at the park. The park is located on the Mississippi River-Great Lakes drainage divide. A brochure is available in the pavilion. There is a short nature trail. Weather permitting, features of the Canadian shoreline 40 miles and more distant may be observed. A faint pale yellow or tan haze is often in the lower atmosphere. This haze is the drifting air pollution from the mid-western U.S. In spite of our somewhat pristine surroundings, the nearby National Atmospheric Deposition Program station sometimes registers the highest acidity and deposition. The acid portion of deposition is buffered by the calcareous glacial till.

Kame and kettle topography of the Lake Escarpment Moraines.

Note kame and kettle topography.
Chautauqua Road is often perched on one of the moraine ridge crests. For about 0.6 mile the moraine ridge under the road is the St. Lawrence - Mississippi watershed divide

Note the lack of gully erosion
Note the lack of gully erosion in the ravines to the left as we drive along Chautauqua Road.

STOP 5. In the Brocton Reservoirs drainage basin.
Parking on roadside.

Brocton Reservoirs
The largest of the three reservoirs supplying the Village of Brocton (Brocton Reservoir) is north, on the right side of Burr Road. The sloped bank on the left (south side of the road) is the earthen dam of Burr Reservoir. A third small reservoir (Risley Reservoir) is out of view on the left (south).

Top of the Glacial Lake Warren shoreline
Rt. 20, again, as at the beginning of the trip, follows mostly on top of the Glacial Lake Warren shoreline (gravelly sand).

STOP 6. Renovated gully draining into Minton Reservoir.
Park on roadside. We will enter the forest at the gated dirt road to the right. This road was cut to give access to the gully so gabions could be placed for erosion prevention.

STOP 7. Westfield Water Works.

SunA: PENN DIXIE PALEONTOLOGICAL AND OUTDOOR EDUCATION CENTER - Visit to a Classic Geological and Outdoor Education Center
Jerold C. Bastedo
Vanasse Hangen Brustlin, Inc. and
Hamburg Natural History Society, Inc.
S-5215 Orchard Avenue
Hamburg, New York 14075
jbastedo@vhb.com
The site of a former quarry operation in Hamburg, New York (Fig. 1), was once the source of calcareous shale excavated and used for cement aggregate by the Penn Dixie Cement Company. A majority of the 57-acre site was quarried from the early-to-late 1960s, during which time 9 to 10 feet of shale was removed from the surface. A gray, somewhat flat "lunar landscape-appearing'' surface now occupies a majority of the site. After the quarry operations ceased, weathering forces began to reveal 380-million-year old Devonian fossils preserved within the Windom Shale. This highly fossiliferous unit underlies the entire site and provides an inexhaustible supply of fossils. In addition to the Windom Shale, several limestone units (the Genundewa, North Evans, and Tichenor) that outcrop on the site are also fossiliferous.
Professional and amateur paleontologists began visiting the Penn Dixie Site, which has often been referred to as the Bay View Quarry, in the early 1970s on a regular basis. Classes from numerous regional universities and the Buffalo Museum of Science began to regularly visit the site to collect the well-preserved, diverse, and highly abundant numbers of invertebrate fossils. Fossil fish and carbonized plant remains have also been collected, but with more difficulty. During the 1970s, 1980s, and early 1990s, the Penn Dixie Site changed ownership, and at times it was difficult acquiring access. It was also during this time period that the former quarry served as a "playground" for all-terrain vehicle (ATV) driving, target-shooting, and youth parties, and as a dumping area for stolen cars and other materials. Many who visited the site during this time period will remember ducking for cover, jumping out of the path of ATVs, and avoiding the broken glass and debris left over from parties.

STOP 1. Penn Dixie Paleontological and Outdoor Education Center
Continue west to entrance road of the Penn Dixie Paleontological and Outdoor Education Center and meet in the parking area on site. The field trip will begin with an introduction to the Penn Dixie Site and a visit to the important exposures and fossil areas present on the site. Representative fossils preserved in the Genundewa and North Evans Limestones, Windom Shale, Tichenor Limestone, and Wanakah Shale may be collected.

SunB: "NUNDA SANDSTONE" DEPOSITIONAL EVENT IN THE PIPE CREEK BLACK SHALE, SOUTH WALES - VARYSBURG AREA, NEW YORK
Gordon C. Baird
Department of Geosciences
SUNY Fredonia
Fredonia, NY 14063
Robert Jacobi
Department of Geology
876 NSC
SUNY at Buffalo
Buffalo, NY 14260
ABSTRACT
The Upper Devonian (Frasnian) Nunda Member of the West Falls Formation is characterized by siltstones and sandstones of gravity flow origin, and is marked by distinctive, thick sandstone units at its top in southern Wyoming County, New York. Recent study of these thick, culminating beds shows that the shales and thin sandstones interbedded with most of the thick sandstones can be correlated westward with the Angola Shale Member, whereas the uppermost massive layers of the Nunda are interbedded with black shales of the Pipe Creek Member-succession. Hence, the Angola-Pipe Creek boundary extends eastward into the uppermost part of the Nunda succession; for this reason we herein refer to Angola-equivalent sandstones as Nunda and Pipe Creek-equivalent sandstones as "Nunda."
Both the Nunda and "Nunda" intervals thicken eastward and southeastward impressively near South Wales in eastern Erie County, and massive 3-6 m thick sandstone beds develop in the uppermost Nunda and "Nunda" in Wyoming County. "Nunda" facies is expressed as grey to brown, micaceous sandstone that can be laminated, massive or chaotic. The "Nunda" succession typically displays a sharp basal contact with silty grey, Angola-type mudstone beds as well as with the basal part of the Pipe Creek shale but has a complex interfingering relationship with overlying Pipe Creek shale deposits. Locally the "Nunda"-Pipe Creek lithologic boundary is characterized by disturbed bedding. Sharply defined olistoliths observed within the lower part of the "Nunda" in two localities are composed of Pipe Creek-type black shale clasts including one observed clast displaying what is probably the Angola-Pipe Creek contact. This evidence suggests that the "Nunda" records one or more large gravity flow events that occurred during the time of Pipe Creek black mud deposition and which, at least locally, scoured up the Angola Shale-Pipe Creek Shale contact.

SunB: "NUNDA SANDSTONE" DEPOSITIONAL EVENT IN THE PIPE CREEK BLACK SHALE, SOUTH WALES- VARYSBURG AREA, NEW YORK

STOP 1. Eighteenmile Creek between NY 5 and North Evans, Erie Co., NY
Tichenor Limestone and Windom Shale of the Hamilton Group; North Evans Limestone, Penn Yan Shale, Genundewa Limestone, and West River Shale of the Genesee Group; and Middlesex Shale and Cashaqua Shale of the Sonyea Group.
The gorge of Eighteenmile Creek, formed by the resistant cliff forming Rhinestreet Shale of the West Falls Group, exposes Givetian (Middle Devonian) and Frasnian (Upper Devonian) strata that can also be seen on the shore of Lake Erie. North of the stone railroad bridge to the mouth of the creek the upper Hamilton Group and Genesee Group strata are exposed (Figure 1).
The oldest unit exposed along Eighteenmile Creek is the Wanakah Shale Member of the Ludlowville Formation (Figure 2). The Wanakah consists of soft fossiliferous medium gray calcareous shale. Decimeter scale cycles within the Wanakah record facies and sea level shifts (Batt, 1996; Batt, 1999, herein).
The Tichenor Limestone ("Encrinal Limestone" of Grabau, 1899) rests disconformably on the Wanakah Shale and marks the base of the Moscow Formation. The base of the Tichenor is sharp and irregular, characterized by prod marks and hypichnial burrows. This erosion surface is a cut down that includes over 5 m of strata present to the east in the Genesee River Valley (Figure 3a). The Tichenor at Eighteenmile Creek is a 30 to 40 cm thick medium to pinkish gray pyritic biowackestone-grainstone. It contains reworked pyrite and shells from the Ludlowville, as well as large rugose corals, favositids, crinoid columnals, brachiopods, trilobites, and bivalves. The top of the Tichenor is also disconformable, representing a submarine hard ground surface with crinoid holdfasts, encrusting corals, and mineral crusts of phosphate and pyrite. Key taxa visible on the upper surface of the Tichenor include large rugose corals and Favosites, numerous brachiopods including: Spinocyrtia granulosa, Orthospirifer marcyi, Mediospirifer audaculus, Pustulatia pustulosa, and Elthyra fimbriata. Also present are the bivalves Plethomytilus and Actinopteria, platyceratid gastropods, and large trilobites of the genus Phacops. Immediately above the Tichenor is a thin (6 cm-thick) bed believed to be a condensed erosional remnant of the Kashong Shale Member, which can easily be confused as part of the Tichenor. This bed yields Tropidoleptus carniatus in association with Spinocyrtia and Orthospirifer.
Above the Tichenor and condensed Kashong Shale is the Windom Shale Member of the Moscow Formation. The Windom is 4.3 m thick along Eighteenmile Creek, bounded by discontinuities (Figure 3b; Baird and Brett, 1986), consisting of soft fossiliferous medium to dark gray calcareous shale, calcareous mudstone, and muddy carbonates. Soft shale at the base, with an abundance of Ambocoelia umbonata, is overlain by the Bayview Bed, a unit yielding a diverse fauna, including patchy concentrations of the large rugose coral Heliophyllum and Cystiphylloides, the brachiopods Spinotrypa, "Mucrospirifer" consobrinus, Mediospirifer, and abundant bryozoans. This bed is interpreted as a relative regression compared to adjacent Windom strata (Baird and Brett, 1983). The Bayview Bed is 36 cm above the Tichenor and offers the best opportunity for collection of macrofossils. Above the Bayview Bed is the Smoke Creek Bed, a 20 cm thick calcareous mudstone (Brett and Baird, 1994). The Smoke Creek Bed is characterized by an abundance of the small solitary rugose corals Stereolasma and Amplexiphyllum, the brachiopods Pseudoatrypa and "Mucrospirifer" consobrinus, and abundant Phacops, both whole individuals and molt assemblages. This bed lacks large corals and Spinatrypa, both common in the underlying Bayview Bed, and is believed to mark a transgressive transition into the fossil-poor mid-Windom facies (Brett and Baird, 1994).
Above the Smoke Creek Bed is a 2.5 m interval of unfossiliferous gray mudstone that correlates eastward to a sparsely fossiliferous interval designated the "Bear Swamp Interval" (Brett and Baird, 1994). Above the Bear Swamp equivalent is a concretionary limestone unit containing Emanuella praeumbonata. This layer correlates to the base of the mid-Windom dark gray transgressive shale interval designated the Fisher Gully beds (Brett and Baird, 1994). The uppermost Windom at Eighteenmile Creek yields sparse Emanuella praeumbonata and small concretions that correspond to the main part of the Fisher Gully beds in the Finger Lakes region (Figure 3b). The Windom succession on Eighteenmile Creek is condensed and truncated. Only the upper part of the Ambocoelia beds are present, and all of the upper-Windom succession (Tauton beds, Spezzano Gully beds, Gorge Gully beds, and newly discovered higher Windom strata in east central New York) is beveled (Figure 3c).
The North Evans Limestone ("Conodont Bed" of Hinde, 1879; Grabau, 1899), the basal stratum of the Genesee Group at Eighteenmile Creek, disconformably overlies the Windom Shale and represents a condensed and reworked bed at the great Taghanic Unconformity, a compound unconformity of several disconformities within the upper Hamilton and lower Genesee groups. To the east this erosive on lap is marked by the Leicester Pyrite, but here this major disconformity cuts out the upper Windom Shale, the Tully Limestone and its equivalents, most of the Geneseo and Penn Yan shales, and the lower Genundewa Limestone. The North Evans Limestone is lenticular, up to 15 cm thick, medium dark gray pyritic, glauconitic biograinstone. The limestone is rich in crinoid ossicles, fish plates, shark teeth, brachiopods, styliolinids, and abundant conodonts, including Polygnathus linguiformis, Polygnathus dengleri, Polygnathus dubius, Polygnathus pennatus, Klapperina cristatus, Klapperina disparalvea, Icriodus latericrescens, Ancyrodella rotundaloba, and Ancyrodella recta, a mix of upper Givetian and lower Frasnian taxa. The North Evans Limestone likely represents multiple reworking events; locally thin black shale partings, lithologically similar to the Geneseo and Penn Yan shales, are present.
A lenticular, up to 3 cm thick, dark gray styliolinid-rich shale overlies the North Evans Limestone. This shale is lithologically similar to the upper Penn Yan Shale, which to the east underlies the Genundewa Limestone and reaches a thickness of 11 m in the Genesee River Valley.
The Genundwa Limestone ("Styliolina Limestone" of Grabau, 1899) is a thin and wavy bedded medium gray bio-grainstone approximately 20 cm thick, and represents a starved basin "cephalopod kalken" dominated by a pelagic fauna of styliolinids, conodonts, locally cephalopods, and terrestrial derived wood. This bed is believed to be the uniformly-bedded upper Genundewa Limestone of the Genesee River Valley and Canandaigua Lake region. The nodular lower Genundewa of eastern exposures, with the ammonoids Koenites and Tornoceras,is missing here. Conodont dating of the Genundewa is complicated by occurrences of reworked and transported elements of the North Evans fauna at the disconformity between the lower and upper Genundewa. The fauna of the lower Genundewa includes the late form of Ancrodella rotundiloba and Ancyrodella recta, indicating lower Frasnian MN Zone 2. The fauna of the upper Genundewa, also with Ancyrodella recta, marks the entry of the early form of Ancyrodella rugosa indicating MN Zone 3 (Kralick, 1994). In the Genesee RiverValley the upper Genundewa marks the entry of the key Frasnian ammonoid genus Manticoceras.
The West River Shale on Eighteenmile Creek is 2.5 m thick, consisting of dark gray shale interbedded with thin siltstone beds and a concretion zone. Styliolina and the pelecypod Pterochaenia are both common. To the east, in the Genesee Valley and Canandaigua Lake region, thin limestones in the lower West River mark the entry of Ancyrodella alata (MN Zone 3). Concretions in the middle West River contain Palmatolepis transitans and mark the start of MN Zone 4 (transitans Zone). Here at Eighteenmile Creek the Williamsburgh Bed, a thin lenticular styliolinid-rich grainstone rich in wood, pyrite, and conodonts is tentatively recognized 0.5 m above the top of the Genundewa. This bed represents a sea level rise and recurrence of sediment starvation similar to the Genundewa Limestone. The conodont fauna of the Williamsburgh Bed includes Ancyrodella alata, Ancyrodella rugosa, Icriodus nodosa, Mesotaxis asymmetricus, Mesotaxis ovalis, and Palmatolepis transitans. The upper 2 m of the West River Shale at Eighteenmile Creek is correlated to the upper three meters of the West River in the Genesee River Valley where the entire formation is over 10 m thick. Individual beds of dark shale, siltstones, and concretions are recognizable. The lower West River is highly condensed or missing entirely in the westernmost exposures.
The Middlesex Shale, a black finely laminated pyritic and petroliferous shale, is 1.8 m thick at Eighteenmile Creek, and marks the base of the Sonyea Group. Millimeter and centimeter scale rhythmic laminations indicate small scale cycles (see Algeo and Woods, 1994), but their cause is problematic. Concentrations of wood and conodonts indicate intervals of even greater sediment reduction. The occurrence of Ancyrodella gigas (transitional to Ancyrodella nodosa) and possibly Palmatolepis punctata indicate a position at or near the boundary between MN Zone 4 and MN 5 (punctata Zone).
The Cashaqua Shale, 12.8 m thick at Eighteenmile Creek, consists of light to dark green-gray shales and numerous concretion intervals. Concretion horizons, relatively evenly spaced through the Cashequa, represent lower sedimentation rates and relatively greater carbonate accumulation and mobility after deposition, but before final compaction. The ammonoid cephalopods Manticoceras sinuosum and Probeloceras lutheri occur in the shales and concretions at several levels associated with the conodonts Ancyrodella gigas, Ancyrodella nodosa, Mesotaxis asymmetricus, and Palmatolepis punctata, indicating MN Zone 5. The prominent concretion horizon in the dark shale band near the top of the Cashaqua is the Shurtleff Septarian Horizon; it lies just below the base of the black Rhinestreet Shale. To the east this bed contains baritized ammonoids, including Manticoceras sinuosum and Prochorites alveolatus, as well as the conodonts Palmatolepis punctata, Ancyrodella nodosa, and Ancyrognathus ancyrognathoideus, indicating MNZone6.

STOP 2. Angel Falls on Beaver Meadow Creek at Java Village, Wyoming Co., NY.
Upper portion of Nunda Sandstone, basal Pipe Creek Shale, "Nunda" Sandstone and the medial and upper Pipe Creek Shale.
Two thick bedded sandstone units are visible in Angel Falls on Beaver Meadow Creek in Java Village (Figure 4). This is the uppermost part of the greater Nunda Sandstone succession characterized by light gray thin to thick bedded cross-laminated and bioturbated coarse silt - very-fine quartz sand. The gray sandstones and silty mudstones at the base of the falls are separated from the upper sandstone that forms the top of the falls by a thin (10 cm-thick) black shale that marks the base of the Pipe Creek Shale Member. The lower and medial part of the Nunda Member interfingers and grades westward into the Angola Shale. The upper sand is stratigraphically distinct, designated "Nunda," as it interfingers and toes out westward within the Pipe Creek Shale (Baird and Jacoby, 1999, herein, Fig. 1). The base of the "Nunda" sharply overlies the thin basal black shale bed; the top is interbedded and mixed with black shale.
The brownish lumpy sandstone of the topmost "Nunda" and super-adjacent Pipe Creek Shale show chaotic bedding, irregular sandstone masses, and complex swirly interlayering of micaceous sandstone and sandy black shale. Diffuse breccia clasts of black shale within brown sandstone matrix suggests emplacement of fluidized sand into variable water-rich, surficial black mud deposits. The thick "Nunda" sandstone seems to be a major fan lobe sand unit (Jacobi et al., 1994; Baird and Jacobi, herein). The "Nunda" flow event scoured the lowest Pipe Creek Shale as indicated by olistoliths of Pipe Creek Shale within the massive unit at several localities. The uppermost chaotic and diffuse "Nunda" Sandstone may represent later, smaller flow events.
The Pipe Creek Shale is the northern Appalachian Basin equivalent to the Lower Kellwasser Horizon in Europe (Over et al., 1997; Over, 1997). Conodonts in the Pipe Creek Shale include Palmatolepis winchelli, Palmatolepis aff. Palmatolepis hassi, and Polygnathus samueli, indicative of the boundary

STOP3. Glade Creek, Wyoming Co., NY.
Hanover Shale, Frasnian-Famennian boundary mass extinction, and Dunkirk Shale.
The Hanover Shale in the Buffalo Creek Valley is predominantly green-gray pyritic silty shale. Dark organic-rich shale, muddy limestones, siltstones, and calcareous concretions are common (Figure 5). Three distinctive black shale intervals and numerous thinner black shales correspond to deepening phases or circulation changes and preservation of organic material in the substrate. The upper Hanover Shale is characterized by numerous black shale interbeds, indicative of deepening and a reduction in coarser clastic influx, as well as reduced oxygen levels in the substrate. The black shales amalgamate or are truncated westward (Baird and Lash, 1990), as a result of sediment reduction and/or submarine erosion. Black shales and calcareous concretions contain carbonized plant material, gastropods, crinoid debris, pteriacid bivalves, cephalopod aptyci, and an abundant and diverse conodont fauna. The upper Hanover at this locality is the source of the large goniatite Sphaeromanticoceras rickardi the last known manticoceratid of the New York Frasnian (House and Kirchgasser, 1993). A radical change in the conodont fauna marks the Frasnian-Famennian.
The Frasnian-Famennian boundary is one of the major biotic events in the Phanerozoic, recognized by the extinction of shallow water corals, most stromatoporoids, and numerous species and higher groups of trilobites, cephalopods, brachiopods, and conodonts. The mass extinction is associated with sea-level fluctuations and deposition of organic-rich fine-grained sediments in tropical seas. In Europe the Kellwasser horizons, two distinct organic-rich intervals, mark the onset and culmination of the extinction. It is estimated that 22 percent of extant families and 65 percent of extant genera went extinct (Hallam and Wignall, 1997). There is no compelling evidence for the single impact of a large bolide as the cause of the extinction (Walliser, 1995; Over et al., 1997).
The thick black shale corresponding to the Upper Kellwasser horizon is characterized by a diverse and abundant nektic and planktic fauna. Locally there are numerous homoctinids, pteriacid bivalves, Sidetes (cephalopod aptycus), current aligned orthocone nautiloids and conodonts, articulated fish, and carbonized plant remains. The conodont fauna is characterized by Palmatolepis bogartensis, Palmatolepis winchelli, Ancyrodella sp., Ancyrognathus sp., Icriodus alternatus ssp., and Polygnathus sp. The concentration of fossil remains in the top of the bed indicates relatively slow sedimentation, that in association with the finely laminated pyrite-rich shale, suggests a relative sea level rise and submarine erosion. Numerous graded and current oriented silt laminae indicate turbidity flows or other bottom currents during black shale deposition. Hummocky cross laminated siltstones in the boundary interval indicate that these strata were deposited near storm wave base.
Fossil abundance drops precipitously above the Upper Kellwasser black shale, corresponding to the Frasnian extinction horizon. Recovery of conodont and benthic fauna is evident in the overlying meter of the Hanover. A ripple laminated 5-8 cm thick, medium gray coarse siltstone, that consists of three fining upward intervals, 1.2 m above the extinction boundary, contains a diverse offshore shelf brachiopod fauna that represents a concentrate from the underlying greenish mudstones. The fauna consists of Schizophoria sp., Thiemella cf. Thiemella leonensis (Hall), Whidbornella cf. Whidbornella lachrymosa (Hall), "Chonetes" cf. "Chonetes" setigera (Hall), Evanoscirostrum? sp., Athryis angelica (Hall), Tylothyris aff. Tylothyris mesacostalis (Hall), Cyrtospirifer cf.Cyrtospirifer inermis (Hall), and Linguloides? sp. These are taxa that carry over from the Frasnian, and suggest a relatively high survival rate for deep shelf brachiopods. This bed also contains numerous specimens of Palmatolepis triangularis, fish remains, and bivalves. Brachiopods are present in the under- and overlying strata, but are only concentrated in a single interval in the middle of the bed, developed in a coarser and more pyritic zone over clay-rich and bioturbated laminae. The pyrite and shell interval overlies a low relief scour surface, indicating a concentration of coarser and denser material during higher energy conditions. The shell-bearing bed is characterized by low amplitude ripple marks that have a 6-7 cm frequency where the ripple crests are oriented NNE-SSW. Brachiopods, and in a lesser abundance crinoids, ostracodes, bryozoa, fish remains, and conodonts, cover the entire surface of the shell horizon. Many brachiopod valves are disarticulated and convex up, but otherwise there is little shell abrasion or other evidence of transport. Some of the larger brachiopod shells are at the top of the bed and concave up, possibly the result of suspension and settling. Abundant lingulid valves (n = 184) have a preferred, but not pervasive, long axes alignment in a NW-SE orientation, perpendicular to the current ripple crests.
The Dunkirk Shale, the lowest formation in the Canadaway Group, overlies the Hanover Shale. The Dunkirk is defined by the first occurrence of massive black shale above the green-gray shales and thin black shale interbeds of the Hanover, and is equivalent, at least in part, to the lower part of the Huron Shale in Ohio. The type section of the Dunkirk Shale is at Pt. Gratiot, Town of Dunkirk, on the Lake Erie shoreline. The basal Dunkirk yielded Palmatolepis triangularis, Palmatolepis subperlobata, Palmatolepis delicatula delicatula and Palmatolepis clarki, characteristic of the Middle triangularis Zone. These species range into succeeding zones, but with the exception of juvenile specimens suggestive of Palmatolepis perlobata ssp. or Palmatolepis tenuipunctata, conodonts indicative of the Upper triangularis Zone or younger were not recovered. Palmatolepis glabra, Palmatolepis perlobata, Palmatolepis quadrantinodosalobata, Palmatolepis subperlobata, and Ancyrognathus bifurcatus were reported by Hass (1958) from the South Wales and Gowanda formations, which overlie the Dunkirk. This fauna is characteristic of a position no lower than the crepida Zone.

SunC: FOSSIL FAUNAS AND MICROSTRATIGRAPHY OF THE UPPER LUDLOWVILLE FORMATION: SMALL-SCALE SEA LEVEL FLUCTUATIONS AND CONVERGING UNCONFORMITIES
RICHARD J. BAIT
Department ofEarth Sciences
Buffalo State College
Buffalo, NY 14222
The Middle Devonian (uppermost Eifelian-Givetian) Hamilton Group of New York State has long been known for its abundance and diversity of well-preserved marine fossils. Sands and muds eroded from the Acadian Mountains that rose to the east (present directional sense) in response to the collision of Laurussia with Avalonia accumulated at the northern end of the Appalachian Foreland Basin, a northeast-trending trough that subsided as the crust isostatically adjusted to the weight of the growing mountain range. A steep siliciclastic-dominated slope descended westward from a nearshore sandy platform into the deep, axial part of the basin, which at the time passed through the present-day Finger Lakes region (Brett and Baird, 1990). Beyond that a western muddy carbonate shelf rose gently toward the shoaling Findlay-Algonquin Arch.
Western shelf sequences include intervals of gray to black mudrock punctuated by thin, laterally persistent bioclastic and diagenetically enhanced limestone beds and calcareous concretion horizons. The carbonate horizons were long known as widely-traceable marker beds; the intervening, seemingly monotonous mudrock intervals have only recently been shown to consist of distinct and widely traceable "depositional units." For example, Batt (1996) distinguished more than 190 depositional units comprising the 20.6 m thick Wanakah Shale Member (Ludlowville Formation) exposed along Rush Creek in Erie County.
Each depositional unit includes two major parts: a basal fossil-rich horizon ("shell bed") overlain by a relatively fossil-poor shale or mudstone. The basal part includes the remains of organisms that accumulated during periods of time (perhaps hundreds or thousands of years) when little if any mud was transported across the deep basin to this offshore shelf setting (Fig. 1 ). The overlying fossil-poor mudrock represents mud that had been re-suspended from nearshore areas and transported into the area during major storm events. The mud blanketed large areas of sea floor, burying accumulated remains and living communities to promote excellent fossil preservation. A given layer of storm-transported mud (mud tempestite of Brett et al., 1986) is an isochronous bed which, when considered with the underlying shell bed, may be correlated on the basis of lithology and fossil content. The widespread correlation of these depositional units allows the creation of a highly refined chronostratigraphic framework that facilitates the testing of various concepts of paleoecology and sequence stratigraphy on a regional and temporal basis.
The current investigation examines the fossil faunas and "microstratigraphy" of the upper part of the Ludlowville Formation of the Hamilton Group in western and west-central New York State. Cyclic vertical (up-section) lithologic and faunal changes suggest that deposition was affected by sea level fluctuations of various magnitude. The upper part of this interval also contains several unconformities which may with detailed correlation be shown to merge westward into a single erosion surface separating what remains of the Ludlowville Formation from the overlying Moscow Formation.
Note: Section descriptions for stops are arranged from the top bed downward. Corresponding depositional units discussed in text are provided for each interval described. Prominent fossils are listed for each bed; these are not complete faunal listings.

SunC

STOP 1: JAYCOX RUN
Exposures along the south fork of Jaycox Creek, on the property of William P. Wadsworth (White Devon Farm), about 0.8 km (0.5 mi) north of Nations Road, Geneseo, Livingston County, NY.
This site is PRIVATE PROPERTY; in order to collect, PERMISSION MUST BE OBTAINED.
This section, the eastern-most one we will visit, illustrates all of the members and major marker beds of the study interval. Some of the beds present in sections further east have already been removed here in various unconformities.
SECTION DESCRIPTION:
J15-J17 94 cm COTTAGE CITY CORAL BED
Three limey, fossil-rich beds, each overlain by an interval of less fossiliferous shale. Corals: Heliophyllum, Eridophyllum, Cystiphylloides, Amplexiphyllum, Stereolasma, Favosites. Bryozoans: fenestellids, Sulcoretipora, Lichenalia. Brachiopods: Pentamerella, Parazyga, Mesoleptostrophia, Protodouvillina, Athyris, Devonochonetes, Rhipidomella. Trilobites: Phacops, Monodechenella. Abundant crinoid debris. 20 species identified from these beds.
J10-J14 77 cm Several beds of hard shale with two prominent fossil-rich horizons. Corals: Amplexiphyllum, Stereolasma, Aulocystis; bryozoans: fenestellids, Sulcoretipora, Lichenalia; brachiopods: Devonochonetes, Stropheodonta, Mesoleptostrophia, Protoleptostrophia, Protodouvillina, Mucrospirifer, Mediospirifer, Pentamerella, Parazyga); mollusks, trilobites, abundant crinoid debris. Beds contain more than 30 species.
J9 31 cm "SPONGE-MEGASTROPHIA BED"
6 cm shell bed overlain by 25 cm shale. Corals: Eridophyllum, Amplexiphyllum; bryozoans: fenestellids, Lichenalia; brachiopods: Megastrophia, Mesoleptostrophia, Stropheodonta, Orthospirifer, Parazyga, Pentamerella; trilobites: Phacops, Greenops. Abundant crinoid debris. 22 species.
J8 29 cm Medium gray hard fissile shale with crinoid debris. 16 species noted, dominantly fenestellids, Stereolasma, Protodouvillina, Phacops, Monodechenella.
J6-J7 30 cm GREENS LANDING CORAL BED
Hard medium gray shale with abundant crinoid debris. More than 30 species noted. Corals: Heliophyllum, Cystiphylloides, Cyathophyllum, Eridophyllum, Thamnoptychia, Favosites, Pleurodictyum; bryozoans: fenestellids, Sulcoretipora, Lichenalia; brachiopods: Protodouvillina, Orthospirifer, Pentamerella, Parazyga. Phacops the dominant trilobite.
J2-J5 50 cm Three beds hard fissile medium gray shale; more than 35 species. Corals: Amplexiphyllum, Cyathophyllum, Favosites, Pleurodictyum; bryozoans: fenestellids, Sulcoretipora, Lichenalia; brachiopods: abundant Tropidoleptus and chonetids; also Mediospirifer, Orthospirifer, Rhipidomella, Pentamerella, Athyris. Various gastropods and pelecypods. Trilobites: Phacops, Dipleura. Crinoid debris rare.
J1 28 cm HILLS GULCH BED
Hard massively fissile bed at top of waterfall. More than 30 species. Corals: Amplexiphyllum, aulocystids; bryozoans: fenestellids; brachiopods: Orthospirifer, Athyris, Parazyga; pelecypods: Pseudaviculopecten, Actinopteria, Mytilarca, Pterinopecten, Grammysioidea, Gosseletia, Cypricardella, Modiomorpha; gastropod: Mourlonia; cephalopod: Nephriticerina; trilobite: Phacops. Crinoid debris very rare.
S5-S6 45 cm Upper part of Spafford shale. Two beds of hard bluish gray, massively fissile shale with few fossils. 12 species noted. Coral: tiny Pleurodictyum; brachiopods: Mucrospirifer, Tropidoleptus, Euschuchertella, chonetids, Mediospirifer, Cupularostrum; pelecypod: Nuculoidea; gastropod: Euryzone; orthoconic nautiloid.
S1-S4 37cm LIMERICK ROAD BED
Represented here by two beds of hard medium gray, Zoophycos-swirled shale with more than 20 species. Coral: Pleurodictyum; brachiopods: Mucrospirifer, Tropidoleptus, Protoleptostrophia, Mediospirifer, Orthospirifer, Athyris, Cupularostrum; mollusks: Nuculoidea, Nuculites, Grammysioidea, Palaeozygopleura, Euryzone, Mourlonia, orthocones. Crinoid debris rare.
B29 18 cm UPPER ROMULUS BED
Soft dark gray shale with less than 20 species. Brachiopods: Mucrospirifer, Athyris, Mediospirifer, Orthospirifer, Cupularostrum; gastropods: Mourlonia, Palaeozygopleura; cephalopods: orthoconic nautiloids, Agoniatites. Base marked by prominent granular pavement of Crurispina nana (condensed upper part of lower Romulus Bed).
B23-B25 49 cm LOWER ROMULUS BED
Represented here by 2 beds of hard dark gray fissile shale with several closely-spaced pavements of Crurispina nana (90% of fauna). Also chonetids, Mucrospirifer, Eumetabolatoechia, Euryzone. Thin (1 cm) clay at base may represent bentonite.
B21-B22 7 cm BLOOMER CREEK BED
Hard medium gray fissile shale with 14 species: Mucrospirifer, chonetids, Cupularostrum, gastropods (Euryzone, Retispira), trilobites (Phacops, Greenops).
B17-B20 19 cm UPPER BLASDELL BED
Two beds of hard medium gray fissile shale, more than 20 species. Corals: Stereolasma, Pleurodictyum; bryozoan: Sulcoretipora, brachiopods: Mucrospirifer, chonetids, Orthospirifer, Athyris, Eoschuchertella, Rhipidomella; mollusks (Euryzone, Mourlonia, Palaeozygopleura, orthocones); Phacops. Rare crinoid ossicles.
B12-B16 24 cm LOWER BLASDELL BED
Represented here by two beds of softer medium gray fissile shale, more than 20 species. Corals: Stereolasma, Aulocystis, small Pleurodictyum; bryozoans: Sulcoretipora, fenestellids; brachiopods: Mucrospirifer, chonetids, Orthospirifer, Athyris, Ambocoelia, Pseudoatrypa; mollusks (Paleoneilo, Pterinopecten, orthocones); abundant Phacops, rare crinoid ossicles.
B9-B11 14 cm Represented here by single bed hard dark gray shale with 7 species dominated by Mucrospirifer, Sinochonetes, with Cyrtina, common orthocones, Phacops. No crinoid debris.
B7-B8 23 cm MILESTRIP ROAD BED
Two beds hard dark gray thinly fissile shale with 10 species: Eumetabolatoechia, Mucrospirifer, Sinochonetes, orthocone, Palaeozygopleura, Phacops. Abundant blastoid stem material in lower part. Bedding planes covered with Styliolina.
B1-B6 67 cm Several beds of soft dark gray thinly fissile shale with 10 species. Brachiopods: Eumetabolatoechia, Ambocoelia, Mucrospirifer, Sinochonetes. Also Palaeozygopleura, orthocones, Phacops. Abundant styliolinids.
H1-H3 23 cm SPRING BROOK INTERVAL
Hard dark gray thinly fissile shale with 5 species. Ambocoelia dominant, with Mucrospirifer, Sinochonetes, Phacops.

STOP 2: LIMERICK ROAD SITE (Optional)
Creek on the property of Robert Walton, York, Livingston County, NY.
This stop, not included in the investigation, provides an additional exposure of the Spafford and Jaycox members. Section similar to that described for Jaycox Run.

STOP 3: HILLS GULCH
Creek on the property of Carl Hume, Union Comers, Genesee County, NY.
This site, not included in the investigation, exposes the interval from the upper part of the Buffalo Creek Submember through the Tichenor Member. The general section is described below (thicknesses approximate): SECTION DESCRIPTION:
(not meas.) | Tichenor Member at top of waterfall.
17 cm | Cottage City Coral Bed. Only the lowest of the three coral beds remains after pre-Tichenor erosion.
130 cm | Middle part of Jaycox Member between coral beds.
30 cm | Greens Landing Coral Bed. Numerous large, often elongate and constricted Heliophyllum, also Eridophyllum, Favosites.
17 cm | Shale between Greens Landing Bed, Hills Gulch Bed
25-30 cm | Hills Gulch Bed. Hard silty mudstone with abundant fossils: Mucrospirifer, large spiriferids, Phacops.
30 cm | Upper part of the Spafford Member. Hard light gray massively fissile, poorly fossiliferous shale.
25 cm | Limerick Road Bed. Bluish gray silty mudstone, Pleurodictyum, large spiriferids.
27 cm | Upper Romulus Bed. Soft fissile shale.
75 cm | Lower Romulus Bed. Several beds of soft, thinly fissile shale; pavements of Crurispina.
25 cm | Bloomer Creek Bed. Hard fissile shale with Athyris, Mucrospirifer.
50 cm | Blasdell Bed. Fissile shale with Sulcoretipora, Phacops, diverse brachiopods.
30 cm | Shale below Blasdell Bed to creek level.

STOP 4. BUFFALO CREEK AT BULLIS ROAD
Turn left onto access to old bridge over Buffalo Creek (closed), just before Bullis Road bridge. Park before barricade. DO NOT BLOCK DRIVEWAY! If there is not enough room, continue on Bullis Road across creek, turn sharp left onto access road to other end of old bridge. Walk down to east end of old bridge, take path downstream, then down to creek bank at base of waterfalls.
Buffalo Creek beneath and downstream of Bullis Road bridge, Marilla, Town of Elma, Erie County, NY.
This exposure illustrates the continued westward removal of successively older beds during lowstand events. Most dramatic is the removal of almost all of the shale overlying the Hills Gulch Bed, Greens Landing Coral Bed, and Cottage City Coral Bed. Each of these beds is here represented by a massive fossiliferous limestone characteristic of this shallower western shelf setting. This section also marks the westernmost occurrence of the Bloomer Creek Bed and Romulus Bed of the Buffalo Creek Submember.
SECTION DESCRIPTION:
Note: The Jaycox Member was not sampled for fossils in this investigation, so bed prefixes were not assigned.
TICHENOR LIMESTONE. Massive gray limestones. To 50 cm. Hard bluish gray shale: remains of Jaycox Member above the Cottage City Coral Bed. Locally absent. 0-8 cm.
COTTAGE CITY CORAL BED. Variable thickness over short distances. Massive bluish gray limestone with large corals (rugose and Favosites), crinoids, other fossils. 0-12 cm.
Hard bluish gray shale (escaped pre-CCC Bed erosion). 0-5 cm.
GREENS LANDING CORAL BED. Thickness varies over short distances. Locally the lowest limestone in the waterfall. Fossils similar to Cottage City Coral Bed. 0-15 cm.
Hard bluish gray shale (escaped pre-GLC Bed erosion). 0-8 cm.
HILLS GULCH BED. Massive bluish gray limestone with abundant fossils: crinoid debris, bryozoans, brachiopods (Elita, Parazyga, Protodouvillina, Pholidostrophia, Megastrophia), mollusks (Actinopteria, Platyceras), corals (Heliophyllum, Favosites, Pleurodictyum). 0-16 cm.
S1?-S6? 95 cm PROBABLE SPAFFORD EQUIVALENT
Top two beds (locally absent) massively fissile bluish gray shale with few fossils (Mucrospirifer, chonetids, Agoniatites). Lower beds hard, thinly fissile dark gray shale with Mucrospirifer, Cupularostrum, chonetids, tiny Tropidoleptus, Cyrtina, nuculids.
B29 16 cm UPPER ROMULUS BED
Soft dark gray thinly fissile shale dominated by Devonochonetes and Mucrospirifer. Also tiny Tropidoleptus, Crurispina nana, orthocones, Agoniatites. 10 species.
B23-B24 23 cm LOWER ROMULUS BED
Two horizons of widely-spaced irregular concretions studded with Crurispina nana in hard, dark gray thinly fissile shale. Crurispina nana comprises 80% of fauna of 10 species. Also chonetids, small Tropidoleptus, Mucrospirifer, Cupularostrum.
B21-B22 16 cm BLOOMER CREEK BED
Hard fissile medium gray shale with 15 species. Fauna dominated by Mucrospirifer and chonetids, with common Athyris and Tropidoleptus. Also Cyrtina, Mediospirifer, Pseudoatrypa, Grammysioidea, various pelecypods, Phacops, rare Stereolasma.
B17-B20 45 cm UPPER BLASDELL BED
Four beds of hard fissile dark gray shale, 40 species. Coral: Stereolasma; bryozoan: Sulcoretipora; brachiopods: Mucrospirifer, Devonochonetes, Rhipidomella, Tropidoleptus, Spinocyrtia, Mediospirifer, Nucleospira, Athyris; Phacops. Crinoid debris rare.
B12-B16 68 cm LOWER BLASDELL BED
Five beds of hard fissile to thinly fissile shale, 40 species. Coral: Stereolasma; bryozoans: Sulcoretipora, fenestellids; brachiopods: Mucrospirifer, Rhipidomella, Protodouvillina, Megastrophia, Stropheodonta, Mediospirifer, Spinocyrtia, Cyrtina, Pseudoatrypa, Athyris; various mollusks, trilobites. Crinoid debris rare compared to sections to west.
B9-B11 26 cm Three beds of thinly fissile dark olive gray shale, 15 species. Dominantly Mucrospirifer but Athyris quite abundant. Also chonetids, Mediospirifer, Cyrtina, Nucleospira, trilobites. Rare Stereolasma. No crinoid debris.
B7-B8 49 cm MILESTRIP ROAD BED
Hard dark gray thinly fissile shale, styliolinid-covered surfaces. Widely spaced calcareous concretions at base. 10 species. Dominantly Mucrospirifer and Sinochonetes, with Cyrtina, Eumetabolatoechia, Nuculoidea, Grammysioidea, Phacops.
B1-B6 87 cm Several beds of hard fissile to thinly fissile dark gray shale. Fauna in upper part dominated by Mucrospirifer, with chonetids, Cyrtina, Phacops. Ambocoelia dominant in lower beds. 15 species.
H1-H3 82 cm SPRING BROOK HORIZON
Represented here by several beds of hard fissile shale. One horizon of flattened calcareous concretions near top; two horizons of larger concretions in lower part. Beds contain up to ten species. Dominated by Ambocoelia, with Mucrospirifer, Sinochonetes, Athyris, Phacops; rare Sulcoretipora, Stereolasma, Spinocyrtia, blastoid stems.

STOP 5: EIGHTEENMILE CREEK AT ROUTE 5
South bank of Eighteenmile Creek immediately upstream of Route 5 bridge, Town of Evans, Erie County, NY. This section, Grabau's Section 6, is similar to the Lake Erie Shore section exposed less than 1 mi to the west. It was chosen because of accessibility. NOTE that the exposures along the creek on the north bank, west of the Route 5 bridge, are on private property and are off-limits.
Here the Tichenor can be seen to rest directly on a beveled surface near the top of the lower part of the Blasdell Bed. The entire Jaycox, Spafford, and upper Wanakah down through the upper part of the Blasdell Bed has been removed by pre-Tichenor erosion. Also visible at this locality is the unconformity separating the Tichenor Member from the overlying Windom Shale, with the intervening Deep Run Shale, Menteth Limestone, and Kashong Shale removed during similar lowstand erosion events.
SECTION DESCRIPTION:
NOTE: Numbered beds referred to in the study were defined at the type locality for the Buffalo Creek Submember. Because resolution is greater at the Lake Erie Shore section, several beds here may correspond to one bed at Buffalo Creek. Example: B 15 is represented here by four.
B16 23 cm "STICTOPORA LIMESTONE"
Three hard limey beds packed with fossils (50 species). Prominent fossils include Sulcoretipora, Mucrospirifer, Nucleospira, fenestellids, Phacops, Pseudoatrypa, crinoids, chonetids, Stereolasma, Lichenalia, Rhipidomella, Spinocyrtia, Stropheodonta, mollusks.
B15 22 cm "DEMISSA BED"
Four beds of slightly softer medium gray fissile shale with abundant fossils (50 species). Prominent forms include Mucrospirifer, Sulcoretipora, fenestellids, Stereolasma, chonetids, Stropheodonta, Megastrophia, Spinocyrtia, Mediospirifer, Athyris, Pseudoatrypa, diverse gastropods and pelecypods, orthoconic nautiloids, Nephriticerina, Phacops, Greenops, crinoids.
B12-B14 42 cm Shale of basal Lower Blasdell Bed subcycle. Four beds, Zoophycos swirled. 50 species. Brachiopods: Mucrospirifer, Nucleospira, chonetids, Cyrtina, Cupularostrum, Rhipidomella, Pseudoatrypa, Athyris (abundant), Spinocyrtia, Megastrophia, Stropheodonta. Also Stereolasma, mollusks.
B9-B11 48 cm Four beds of fissile shale, up to 20 species. Dominated by chonetids and Mucrospirifer. Also Mediospirifer, Athyris, Cyrtina, Nucleospira, Stereolasma (few), Greenops, Phacops, orthocones.
B7-B8 30 cm MILESTRIP ROAD BED
Two beds, each with calcareous concretions at base. Abundant styliolinids. Up to 20 species. Mucrospirifer, Athyris (abundant), Stereolasma, Aulocystis, Protoleptostrophia, Cyrtina, chonetids, Phacops, Greenops.
B1-B6 78 cm Seven beds of fissile dark gray shale. 15 species. Mucrospirifer dominates in upper part; Ambocoelia in lower part. Also chonetids, small Tropidoleptus, Cyrtina, Athyris, Eoschuchertella, Aulocystis, Stereolasma, Phacops.
H1-H3 76 cm SPRING BROOK HORIZON
Six beds of hard dark gray thinly fissile shale, including three horizons of large concretions. 20 species. Ambocoelia dominant, with abundant Athyris, also Sulcoretipora, Rhipidomella, chonetids, Protoleptostrophia, Mediospirifer, Mucrospirifer, Phacops.

SunD: HOLOCENE MEANDER INCISION IMPOSED ACROSS A BURIED VALLEY WALL
Michael P. Wilson
Geosciences Department
SUNY College at Fredonia
Fredonia, NY 14063
William T. Boria
Division of Environmental Health Services
Chautauqua County Department of Health
Clothier Building
Mayville, NY 14757
Topics
This field trip provides an opportunity to visit two contrasting kinds of glacially buried valley fills. While looking at buried valley fills in northern Chautauqua County we have noticed that the fills are not internally deformed when not involved in modern landslides. The exception to this scenario occurs where the fills include near-surface outwash and lacustrine sediments among the Lake Escarpment and Lavery Moraines. · These settings show ample evidence of deformation from the melt of underlying ice. Surface land morphology shows well-defined kettle holes and gently undulating surfaces with a few tens of feet of relief Gravel pits show dips that range to between 50 and 90 degrees. Outcrops show folded and faulted sediments.
This trip will provide an opportunity to discuss recent meander incision across a buried valley wall. Our sketches and photography, in addition to published information, allow for a nearly complete reconstruction of meander movement during recent decades.
Although not part of our immediate objective, we will bring with us copies of the 1990 NYSGA Guidebook article by Gilman and Berkley. Their article included one of the stops that we will visit (our Stop 2). Their trek down Chautauqua Creek (and other parts of their article) paid particular attention to brittle structures in the bedrock. We will point these out while we hike to our Stop 2. We have been especially interested in the timing of the development of the pop-up folds. In scanning cliff walls of western and central New York streams, we note the absence of these folds. On the other hand, popups occur routinely at quarter or half mile intervals in stream beds or Lake Erie cliffs. Also noteworthy is that one-meter amplitude folds are very commonly associated with basal tills. The non-glacial pop-ups are apparently related to erosional unloading.

SunD

Fredonia lies mostly on Glacial Lake Warren shoreline and Canadaway Creek delta
The Village of Fredonia lies mostly on Glacial Lake Warren shoreline and Canadaway Creek delta and terrace sand and gravel. We will drive for approximately 15 miles, mainly on top of the Warren shoreline. Often, about 1/2 to 1 mile to the south (left), the Glacial Lake Whittlesey shoreline (approx. 13,000 BP; Muller and Calkin, 1993) can be observed as a 20 to 40 ft. high terrace. Whittlesey shoreline deposits are typically narrower and more gravelly than Warren (Woodbury, 1992; Woodbury and Jenson, 1990). The Lake Escarpment Moraines (approx. 14,000 BP; Muller and Calkin, 1993) cap the top of the Portage Escarpment to the south. The ridge line is about 1000 ft above Lake Erie (1550 ft vs. 573 ft).

STOP 1. Outlet ravine of Minton Reservoir.
Park on the roadside (don't drive all the way to the edge of the bulldozed area). This will be a brief stop to peer into the ravine and observe the nature of the buried valley fill and contrast these materials to those at Stop 2.

STOP 2. Wet-foot trek into Chautauqua Gulf
Parking at end of Taylor Road (remains of gravel pits in kames).

SunE: EARTH SCIENCE FIELD TRIPS FOR HIGH SCHOOL STUDENTS
Brian Muirhead
Southwestern High School
Jamestown, NY
INTRODUCTION: A BRIEF GEOLOGICAL HISTORY OF CHAUTAUQUA COUNTY
Chautauqua County has an exposed geological record dating back about 370 million years to the Late Devonian Period (see geologic time scale, fig. 2). The majority of the bedrock exposed in the county (fig. 1) formed from sediment deposited during that time period, although some scattered outcrops of Early Mississippian bedrock occur southeast of Jamestown near the Pennsylvania state border.
As the Late Devonian progressed, the shoreline of the Catskill Sea in eastern New York gradually shifted westward across the state due to the sediment accumulation. The result was that coarser grained nearshore and terrestrial sediments were deposited on top of finer grained marine sediments. An example of this is represented by the sequence of layers from the Dunkirk Shale up through the Panama Conglomerate (bottom of the Cattaraugus Formation). This stratigraphic succession shows a coarsening upward trend in which sand and pebbles were deposited on top of muds and silts. It is assumed that sediment from the Mississippian Period was then deposited on top of the Devonian sediments over the entire region as the Catskill Sea slowly filled in.
The rock record from the Pennsylvanian Period (Late Paleozoic Era) through the Tertiary Period (Cenozoic Era) is not exposed in Chautauqua County. It is not known whether sediment from that time span was ever deposited in this area or if it accumulated and then was eroded. No bedrock from the Mesozoic Era exists anywhere in western New York.
Chautauqua County is located within two landscape regions: the Allegheny Plateau, which comprises most of the county, and the Erie-Ontario Lowlands, represented by a relatively flat strip of land approximately four miles wide oriented southwest to northeast along the Lake Erie shore. According to Isachsen et al. (1991), uplift of the Allegheny Plateau occurred during the middle of the Cenozoic Era. The Erie-Ontario Lowlands are believed to have formed by erosion prior to glaciation during the Pleistocene Epoch (Gilman and Berkley, 1990).
The Pleistocene Epoch, which began 1.6 million years ago, witnessed four major events of continental glaciation in North America. Only evidence from the last glacial advance, the Wisconsinan Phase, is found in Chautauqua County. As the Wisconsinan ice sheet melted and retreated north from the region it left a deposit of unsorted sediment on top of the Late Devonian bedrock. This deposit, known as glacial till, contains igneous, metamorphic, and sedimentary rocks transported from Canada, as well as pieces of ripped up Devonian bedrock of local origin. The boundary between the bedrock and till is a major unconformity representing a large gap in the rock record of Western New York.
As the ice sheet melted northward, flowing glacial meltwater deposited sediment called glacial outwash within pre-existing stream valleys. Deposits of glacial outwash can be found in several areas, such as Chautauqua Gorge. In addition, the meltwater produced two large glacial lakes that existed before Lake Erie. These lakes have been named Lakes Whittlesey and Warren, and clay and silt deposits from them can be observed on top of glacial till along the Lake Erie shoreline.
The Pleistocene Epoch ended ten thousand years ago with the final retreat of the ice sheet from New York State and thus began the Holocene Epoch. No major geological events have occurred in Chautauqua County since the beginning of the Holocene. Erosion is currently wearing down the Earth's surface with running water as the major agent. Deep gorges, such as Chautauqua Gorge, which cut into the landscape serve as evidence for such erosion.
A southerly bedrock dip (or inclination) of a few degrees and the forces of erosion have produced a distinct outcrop pattern in Chautauqua County (see Tesmer, 1963). The oldest layers are exposed in the northern section of the county while the youngest appear in the south. In the northern part of the county the layers from the Dunkirk Shale up through the Northeast Shale are exposed, or crop out, in a pattern that trends from southwest to northeast, paralleling the Lake Erie shoreline. The bedrock from the Dexterville Siltstone up through the Cattaraugus Formation is best exposed in the central and southern sections of the county.

POINT GRATIOT PARK
Point Gratiot is located in the northern part of the county, in Dunkirk.
At this location these features can be observed:
1. The Dunkirk Shale (see fig. 1)
2. Hydrocarbon odor from freshly broken pieces of black shale
3. Rust stains from oxidation and hydration of iron
4. Bedrock jointing
5. Fossil wood fragments
6. Glacial features:
a. till
b. erratics
c. scratches (striations) on bedrock
7. Devonian/Pleistocene unconformity
8. Shoreline features:
a. beach sediment
b. clast imbrication
c. longshore current
d. headland-cove pattern
9. Soil development in glacial till
UNIQUE FEATURES
BEDROCK: The bedrock at this location is the Dunkirk Shale (see fig. 1), a unit of black shale that was formed from mud deposited on the floor of the Catskill Sea. Black shales form from sediment that is deposited underwater in low oxygen conditions.
HEADLAND-COVE PATTERN: Wave erosion along joints has produced an alternating headland-cove pattern on Point Gratiot where the bedrock is exposed. Because the joints are weakened zones where water can erode the bedrock faster, the heavily jointed sections have become the coves or inlets while the less jointed sections are small promontories protruding out into the water as headlands.
SOIL DEVELOPMENT: The relatively young age of the glacial till makes this site an excellent place to discuss soil development and maturity. Trees, shrubs, and weeds are growing in the soil, but the amount of biological activity and weathering has not been sufficient to produce a mature soil profile containing the A, B, and C horizons. The soil profile here is classified as immature because the B horizon is missing, and more time is needed before weathering produces a mature soil.

STOP 2. DJ'S CAMPGROUND
DJ'S CAMPGROUND
DJ'S Campground is located on the shoreline of Lake Erie, a few miles west of Brocton.
A rock hammer, chisel, and safety glasses will be helpful for collecting fossils at this location.
At this location these features can be observed:
1. The Gowanda Shale (see fig. 1)
2. Bedrock jointing
3. Hydrocarbon odor from freshly broken pieces of dark-gray shale
4. Rust stains from oxidation and hydration of iron
5. Glacial features:
a. glacial till
b. glacial erratics
c. meltwater lake sediments
6. Devonian/Pleistocene unconformity
7. Shoreline features:
a. beach sediment
b. beach berm
c. longshore current
d. clast imbrication
e. storm deposits
8. Septarian concretions
9. Pyrite nodules
10. Ripple marks
11. Fossils: pyritized cephalopods, wood fragments, and trace fossils
12. Erosion by gravity
UNIQUE FEATURES
BEDROCK: The bedrock at this location is the Gowanda Shale (see fig. 1), consisting of light-gray and dark-gray shale with some interbedded thin siltstone.
SEPTARIAN CONCRETIONS: Within the bedrock are elliptical shaped rocks known as septarian concretions. The local people often refer to these as "turtle rocks" because of their resemblance to turtle shells. However, they are not fossilized turtles. Rather, these round concretions form from the precipitation of carbonate minerals in the sediment. When the concretions harden and shrink, cracks form and are filled in by the precipitation of the minerals calcite(CaCO3), siderite (FeCO3), and, more rarely, barite (BaSO4) (Gilman & Berkley, 1990, pg. G11). It is apparent that the concretions grew after the sedimentary layers were deposited because the layers are warped above and below them.
PYRITE NODULES: The existence of pyrite (FeS2) nodules in the bedrock indicates a relatively high iron content. The pyrite nodules formed when iron in the sediment bonded with sulfur produced during the decay of organic material by bacteria in the sediment. Many of the nodules are rust-stained and are chemically weathering like the surrounding bedrock.
RIPPLE MARKS: Some of the thin siltstone layers exhibit ripple marks. Ripple marks form when waves or water currents move across loose sediment.
FOSSILS: This section of the Lake Erie shoreline is famous for its well preserved pyritized fossils. The most interesting fossils belong to the Phylum Mollusca, Class Cephalopoda. Cephalopods are marine organisms that swim by jet propulsion of seawater. Modern examples of these organisms include the nautilus and the octopus. The species of cephalopods at this location have long since been extinct and occur in two forms. One form, the orthoconic nautiloid, has a cone-shaped, segmented appearance. The other form, known as the goniatite, is coiled, much like a snail shell. The layer containing these fossils is near the water level and breaking waves may hinder collecting.
Minor fossils at this location include bits and pieces of carbonized and partially pyritized wood, and trace fossils. The fossilized wood is dark-gray to black from carbon and often contains small pyrite crystals. The trace fossils are burrows produced when sea bottom dwelling organisms roamed through the mud looking for food. They appear in the light gray shale as narrow, curved features slightly darker or lighter in color than the surrounding bedrock.
EROSION BY GRAVITY: The weak glacial lake deposits above the glacial till are very susceptible to erosion by gravity. Evidence of mass movement is the landslide debris on the bluff slope and at the base of the bluff.

STOP 3. CHAUTAUQUA CREEK AT BARCELONA
CHAUTAUQUA CREEK AT BARCELONA
Barcelona is located on the shore of Lake Erie, one mile northwest of Westfield.
At this location these features can be observed:
1. The Westfield Shale (see fig. 1)
2. Root action
3. Rust stains from oxidation and hydration of iron
4. Differential weathering of siltstone and shale
5. Stream erosion and deposition:
a. sediment shape and size
b. gravel bars
c. clast imbrication
d. relationship of particle size to the water velocity of transport
6. A reverse fault
7. A monocline
UNIQUE FEATURES
BEDROCK: The bedrock at this location is the Westfield Shale (see fig. 1), composed of gray shale with some interbedded siltstone.
REVERSE FAULT: Facing upstream, on the right bank is a reverse fault, a fault in which the hanging wall appears to have moved upward relative to the footwall. Some rock and dirt debris may obscure the fault plane, so a shovel would be handy to expose the fault better. Facing the fault, the hanging wall is on the left side of the fault plane and the footwall is on the right. Especially obvious is that the siltstone layers on the hanging wall are not horizontally continuous across the fault plane to the footwall. By comparing the positions of siltstone layers on each side of the fault it appears that the vertical displacement is approximately 4 feet. In addition, the distorted nature of the rock along the fault plane is observable with closer inspection.
MONOCLINE: Another interesting structural feature is the monocline 50 feet upstream from the reverse fault. This fold has layers dipping (tilting) upstream. A monocline is a one-limbed fold, as opposed to anticlines and synclines which have two limbs. The monocline and the fault resulted from probable local compressional stress in the bedrock, although the origin of the stress is unclear.