NYSGA 1967
NEW YORK STATE GEOLOGICAL ASSOCIATION
39th Annual Meeting
May 5-7, 1967
GUIDEBOOK FOR FIELD TRIPS
Editor
Russell H. Waines
HAMILTON COLLEGE
Clinton, New York

A: THE PLEISTOCENE GEOLOGY OF THE WALLKILL VALLEY
G.GORDON CONNALLY
S.U.N.Y. College at New Paltz
LESLIE A. SIRKIN
Adelphi University

A: THE PLEISTOCENE GEOLOGY OF THE WALLKILL VALLEY

Schunemunk Mountain
Railroad Underpass. Schunemunk Mountain, a northeasterly plunging syncline is on the left. This is the easternmost manifestation of typical Appalachian, ridge-and-valley topography.

Salisbury Mills and Moodna Creek
The village of Salisbury Mills with Moodna Creek close by on the left. Moodna Creek served as a major drainage-way for pro-glacial lake waters in the Wallkill Valley and controlled the 400 foot lake level reported by Adams (1934).

Home of Brotherhood Wineries
Washingtonville is the home of the Brotherhood Wineries, reputed to be the oldest in the country in continuing existence.

Post-glacial stream channel
Note the post-glacial stream channel cut in bedrock. This channel is the result of a drainage reversal caused by the deposition of a crevasse filling (moraine?) south of Chester. This stream originally flowed southward into Black Meadow Creek but now drains only the muck area north of Chester.

View of Chester Esker
The Chester Esker is on the right side of the road.

Chester Esker
The road ascends the 60 foot high Chester Esker. This esker has its crest at about 540 feet and evidently represents a channel that drained southward through stagnant ice, into the 500 foot lake in the southern Wallkill Valley. This channel was probably in existence during the building of both the Pellets Island and New Hampton Moraines.

STOP A-1 Gravel Pit
This gravel pit is operated by Chester Ready-Mix. It is part of a southward extension of the ice channel filling represented by the Chester Esker. Examine the relationship between ice-contact stratified drift, flow (?) till, and non-ice-contact drift. In addition, examine the exotic lithologies represented in the gravels.

Ice-margin
Turn left (west) on Route 94. The road essentially parallels an ice-marginal position between here and Florida, New York.

Muck farming
Cross Quaker Creek on small bridge. This is the main muck farming area of Orange County. The organic soil is the result of filling of a 500 foot pro-glacial lake with lake silts and then organic deposits. On approaching the ridge of till knobs to the west a change in color of the topsoil illustrates the change from muck soil (developed from the bog deposits), to Canandaigua soils developed from underlying lake silts and clays) to Cossayuna-Troy soils (developed from the till that underlies the lake deposits).

Drumlinized till ridges
Turn left (south) on the Pulaski Highway following the series of drumlinized till ridges.

STOP A-2 Lodgment Till
Examine the lodgment till exposed in the cut behind the Big Island Garage. This till appears similar in lithology, weathering profile and soil development to the Olean till of western New York.

Distal face of the Pellets Island Moraine
Note the distal face of the Pellets Island Moraine to the front and left. (North)

Proximal slope of the Pellets Island Moraine
The proximal slope of the Pellets Island Moraine is to left.

STOP A-3 Pellets Island gravel pit
This is the Pellets Island gravel pit of the Orange County Sand and Gravel Co. The undisturbed foreset bedding on the distal side of the moraine suggests deposition into the open water of the 500 foot lake level. Exploratory cores for the City of New York Port Authority show almost 100 feet of lake clay, overlain by 0-20 feet of organic muck south of the moraine. Large blocks of flow (?) till are periodically exposed on the proximal side confirming it as an ice-contact face.

STOP A-4. Berkman bog
Leave the buses and cross the road to the west. Walk up the gentle slope parallel to the stonewall until the trail becomes clear in the orchard. Follow the trail for about 1/4 mile before descending into the Berkman bog. The implications of the pollen record will be discussed in relationship with the deglaciation of the region and the drainage history of the bog.

STOP A-5. Phillipsburgh crevasse filling
Leave the buses and gather on the hill on the right side of the road. Observe the Phillipsburgh crevasse filling that trends to the northwest toward the Wallkill River. QUESTION: Why are there no drainage features nor ice-contact deposits to the south and east of this feature?

Crevasse filling on the left
Continue northwest parallel to the crevasse filling on the left and Route 17 on the right.
2010: Route 17 truncates the route shown on the Road Log. Returning to where Owen's Road crosses it gets us to the lunch stop.

Bridge across the Wallkill River.
The river flows on bedrock on the east bank.

STOP A-6 Gravel Pit
This is one of the gravel pits operated by E.Tetz & Sons. Examine the pebble lithology as contrasted with that seen at Stop A-1. QUESTION: What is the significance of the large boulders of Shawangunk conglomerate?

STOP A-7. Large Kettle Hole
Cross through the barbed wire fence on the left side of the road and proceed up the hill to the large kettle hole. Here the significance of the stagnant ice topography found in the Wallkill Valley will be discussed.

Plain of washed till
Turn left (east) on Stoney Ford Road. The road traverses a plain of washed till adjacent to the Wallkill River.

Kame complexes
Turn left (north) at the Stop Sign and drive through more kame complexes similar to stops A-6 and A-7.

Distal slope of the Circleville Moraine.
Ascend the distal slope of the Circleville Moraine. The relationship of this moraine to the Pellets Island and New Hampton Moraines is uncertain.

STOP A-8.
This is one of a number of gravel pits operated by the Dickenson Sand and Gravel Co. of Bloomingburg. Examine the drift lithology. The significance of the numerous crevasse fillings in the Shawangunk Kill Valley north of Otisville will be discussed.
2010: Construction of Route 17 truncates the route given in the road log. The path here will get to the same entrance onto Route 17.

Chester crevasse filling and Chester Moraine
The Chester crevasse filling and Chester Moraine are seen on the left. Camp La Guardia is located on the Chester Moraine.

Mass Wasting
Note the mass wasting evident in the till cut to the right.

Valley-choker Moraine
Note the massive valley-choker moraine to the right. This pit once displayed magnificent forest bedding toward the south.

B: THE ECONOMIC GEOLOGY OF THE MID-HUDSON VALLEY REGION
A diverse terrain endowed with a wide variety of available mineral resources, sustained demand for these resources and economical means of transportation have combined to foster a dynamic mineral industry in the Mid-Hudson Valley region which has prospered since the early 19th century. Production valued at about 100 million dollars in 1965 accounted for approximately one-third of the State1s entire mineral economy. Of greater significance is the fact that the Mid-Hudson Valley's mineral production is concentrated in less than one percent of New York State1s total land area (47,944 square miles). The principal products are crushed stone aggregate, building stone, lightweight aggregate, sand and gravel, portland cement, natural cement and brick - materials all necessary to building and highway construction.
Systematic geologic studies of the nature and use of rock raw materials have produced revolutionary changes in the economics of industrial mineral production in the Hudson Valley during the last decade. The result has been an increase of crushed stone reserves by a factor of 3 to 5, cement reserves by a factor of 5 to 10 and lightweight aggregate reserves from nothing to well over a billion tons. This represents another example of taking what is available and utilizing it all, by separation or by blending, for the most useful purpose. The economic rock section ranges in age from Cambrian to Middle Devonian (Tables Bl and B2).
Trip B is specifically planned to allow participants the opportunity to examine in a day's time the greatest variety of rock raw materials and mineral commodities typical of the Mid-Hudson Valley. The following U.S. Geological Survey 7 .5-minute topographic quadrangles cover the route of the trip in order: Newburgh, Wappingers Falls, Poughkeepsie, Hyde Park, Kingston East, Kingston West, Rosendale and Clintondale.
JOHN H. JOHNSEN
Vassar College
SIMON SCHAFFEL
The City College of New York

B: THE ECONOMIC GEOLOGY OF THE MID-HUDSON VALLEY REGION

STOP 1: Shale quarry and clay pit
Shale quarry and clay pit of the Beacon Brick Corporation Exposed in the quarry are grayish-black, red and green slaty shales of the Normanskill Formation (Table Bl) which are blended with clay to manufacture brick. Note slaty cleavage parallel to bedding. Hudson Valley brick is produced by either the "soft mud" or "stiff mud" process. "Soft mud" brick is made from clay to which an excess of water has been added to secure plasticity. The soft mud is placed in wooden molds which have been dusted with sand and the clay is allowed to dry before firing. Extreme care must be exercised to avoid drying cracks and shrinkage. The "stiff mud" process is used most frequently by the modern brick industry. Highly plastic clays are undesirable for this process so that ground shale is usually added to the mix. The stiffer clay or clay-shale mix is extruded through a rectangular die and bricks are cut off by taut wires. These unfired bricks, being stiffer, can be handled with less danger of deformation. Proceed to clay pit. Exposed in the pit is clay that represents fine mud deposited in one of many meltwater lakes that occupied the Hudson Valley during the retreat of the ice in the Late Pleistocene. The clay is normally bluish gray but it may be yellow when weathered due to the oxidation or iron. Thin beds and lenses of sand are frequently inter-stratified with the clay. The thickness of the clay is variable in this region, but it may exceed 200 feet in some localities. This glacial clay is well adapted to brick manufacture. It is plastic and usually has sufficiently large proportions of fluxing agents - such as alkalies, iron, lime and magnesia - to permit vitrification at relatively low temperatures. The finished product is generally red or pink in color. The Beacon Brick Corporation uses a clay-shale mix to make extruded wire-cut brick. Firing takes place in a tunnel kiln having a capacity of 100,000 bricks per day. The chief market area is New York City with transportation by barge. Lightweight aggregate is manufactured from shale or clay by heating these materials until they expand to form porous, scoriaceous material by the evolution of gas bubbles at elevated temperatures (see Stop 3). The Normanskill Shale is considered a potential source of lightweight aggregate raw material; however, pilot tests of the shale from this area yielded an unsatisfactory product because of the lack of compositional uniformity and the large amount of micro- and mega-structural diversity. The slaty cleavage caused slivery rather than equidimensional fragments on crushing which produced a pleated appearance on bloating similar to expanded vermiculite. Although this structure does not necessarily result in an aggregate of low strength, it does make a less attractive aggregate in terms of consumer acceptance. So far as is known, there has been no attempt to produce lightweight aggregate from Hudson Valley clay.

STOP 2: Clinton Point Quarry
New York Trap Rock Corporation, Clinton Point Quarry Plant Office and loading dock. Hard hats will be loaned to those participants not bringing them. The borrowed hats will be returned at Nytralite Aggregates, Inc. (Stop 3).
Two belts of dolostone suitable for crushed stone aggregate occur along the Hudson River in the lower reach of the Mid-Hudson Valley (see Lower Hudson Sheet, Geologic Map of New York State, 1961). The southern most of these two belts follows the northern margin of the Hudson Highlands north-northeast from the vicinity of Beacon to the eastern portion of Dutchess County where it veers more northerly, eventually crossing into northern Connecticut and Massachusetts; the other belt begins B6 southwest of Newburgh and also trends north by northeast to cross the Hudson at New Hamburg (situated at the mouth of Wappinger Creek) where it occurs in two distinct bands over a short distance and continues in the same north-northeasterly direction to the upper part of Dutchess County.
The rocks take their name, Stockbridge Group, from Stockbridge, Massachusetts, where the northeastern extension of the southernmost belt has been metamorphosed to marble. In the field trip area, the carbonates are unaffected by metamorphism and frequently are referred to as the Wappinger Group, a name well established in the literature. The Stockbridge succession includes carbonate rocks that are Late Cambrian to Early Ordovician in age although that part of the succession in the vicinity of the Hudson River may be all Cambrian. The sequence includes a series of dense to finely crystalline, gray dolomitic rocks ranging from dolomitic limestone to dolostone which collectively are calcitic dolostones.
At Clinton Point, the rock is dolostone, with a magnesium carbonate content of 38.16 percent. Here the New York Trap Rock Corporation, a subsidiary of the Lone Star Cement Corporation, produces every conceivable size of stone ranging from riprap to stone sand and screenings.
The quarry opening is effectively blocked from river view by a 500-foot wide buffer zone or "mercy strip". The dolostone reportedly extends to considerable depth and a portion of the quarry floor is now 60 feet below the level of the Hudson River. Downward development is possible because the rock in the buffer zone is sufficiently tight to hold back the river water.
Two inactive quarries are located in a different part of the dolostone sequence on the west bank of the Hudson opposite New Hamburg at Cedar Cliff. In these quarries the dolostone is locally characterized by considerable chert of a variety that is known to have a deleterious effect when used as concrete aggregate. If reopened, selective quarrying would be necessary until new advances in concrete technology nullify these effects. There is no reason why other applications are not possible, provided the rock meets the necessary specifications.

STOP 3: Nytralite Aggregate, Inc. Quarry
Nytralite Aggregate, Inc. - Quarry and Tour of Plant Nytralite Aggregates, Inc. is one of the leading producers of lightweight aggregate in the Mid-Hudson Valley. Lightweight aggregates are special materials incorporated with cement in the manufacture of concretes- which range in weight from 120 pounds per cubic foot to less than 62 pounds per cubic foot. The latter is able to float on water. By comparison, conventional concretes containing other aggregates, such as crushed carbonate rock seen at Stop 2, weigh about 150 pounds per cubic foot. Lightweight aggregate is used in substantially more than half of the concrete block produced in the United States. The desirable properties gained by this usage are: lightness, high strength-to-weight ratio, low shrinkage, low thermal conductivity, good acoustical properties, a coefficient of expansion similar to that of steel and low production costs. The use of lightweight aggregate in the concrete roadway of San Francisco-Oakland Bay Bridge reduced the cost of steel by three million dollars. Lightweight aggregate may be manufactured from clay or shale by heating these substances until they expand to form porous, cinder-like materials. Expansion is a bloating process in which two conditions occur simultaneously. Upon firing, the clay or shale fuses to form a viscous liquid, while at the same time, a gas, released as a result of mineral decomposition, becomes entrapped within the viscous mass. If the gas-producing mineral, or minerals, decomposes before any appreciable liquid formation takes place, expansion will not occur, as the gas will escape through the open-pore structure. Satisfactory expansion also will not occur if the gas is evolved at temperatures much greater than the softening point, as the gas will again be lost because the melt will be too fluid to retain it. If, for some reason, the gas is retained under this condition, cells may be too large and their walls too thin for good strength. Non-bloating argillaceous materials can often be induced to expand by adding pulverized coal and pelletizing into desired size prior to ignition. The rock most suitable for the manufacture of lightweight aggregate is a massive, somewhat silty (arenaceous); unweathered shale of uniform quality. It may contain a small amount of calcite, either disseminated or as thin veinlets, and a little pyrite. Slaty cleavage should not be well developed, but it causes no problem in its incipient stages. This type of rock yields a good, uniform aggregate of adequate strength and an acceptable appearance. It bloats at approximately 2000 degrees F. The Esopus Shale exposed in the Nytralite quarry fits this description. Note the gentle dip of the massive beds to the southeast (north face) and nearly vertical cleavage (east face). The quarry is located on the gently dipping western limb of an asymmetrical syncline, the axial planes of which dips to the southeast. The trace of the axial plane is roughly parallel to the crest of Fly Mountain. Fly Mountain is basically a northeast-trending asymmetric synclinal ridge characterized by a number of similarly-trending subsidiary folds. It is composed mainly of Late Silurian and Early Devonian carbonate rocks {Figures B3, 84} which have been thrust northwestward over the Esopus Shale along multiple faults. Exit quarry. Cross Route 32 and proceed up road to plant. Exit buses and proceed on foot. Note initial test quarry in Esopus Shale to north. Walk up hill, noting the carbonate rocks, to primary crusher and Plant Office. Route essentially parallels the section given in Figure B4. Plant Office. Lunch stop and tour of plant. Refer to flow diagram {Figure B5}.

STOP 4: Natural Cement Mine, Century Cement Mfg. Co.
Natural cement is produced by calcining an impure, argillaceous limestone or dolomitic limestone containing from 15 to 40 percent silica, alumina, and iron oxide at a comparatively low temperature (about 14000 F.) so that decarbonation but no fusion takes place. The burned mass will not slake if water is added, but when ground to a powder it will harden rapidly with the addition of water. Natural cement acquires most of its untimate strength in 5 years and only one-eighth of its ultimate strength in 7 days whereas most portland cements approach their ultimate strength in one year and reach 65 to 75 percent of their ultimate strength in 7 days.
In the United States, the cement industry began in 1818 with the discovery of natural cement rock near Chittenango, New York, by Canvass White. White applied to the State of New York for exclusive rights to manufacture the cement for 20 years. His request was denied but the State awarded him $20,000 in recognition of his valuable discovery. The cement was used in the construction of the Erie Canal.
In 1825, during the building of the Delaware and Hudson Canal, a natural cement rock was discovered here at Rosendale. Work was progressing along the route of the canal through the farm of Jacob L. Snyder when it became necessary to blast through some rock. The rock, as blasted, had the appearance of limestone and fragments were taken to a blacksmith shop at High Falls to produce lime. The stone was burned in the forge and attempts to slake it were made by adding water. The calcined material, soft and chalky after burning, did not slake but instead, after a few hours, lost all of its chalkiness and began to harden. It had been planned to obtain the cement necessary for the canal locks from Chittenango but with the discovery of cement along the route, a contract was awarded to a Mr. John Littlejohn to supply the canal's needs. Littlejohn built a "pot" kiln in which the burning of each charge was a separate operation. The pot kiln was a shaft excavated in the side of a hill and lined with cement rock. At the base of the kiln, an "eye" or shaft at a right angle to the main shaft was filled with cordwood and an arch of large cement rocks, to act like a grate, was formed just above the cordwood. The kiln was then filled with cordwood and an arch of large cement rocks, to act like a grate, was formed just above the cordwood. The kiln was then filled with broken cement rock and the cordwood ignited. The burning continued until the highest stone in the kiln was calcined (5 to 6 days) and then the entire charge was withdrawn. The kiln was then recharged and the procedure repeated.
The charge, as drawn, contained some raw and some over-burned materials. These were carefully removed and the raw material was used in the next kiln charge while the over-burned material was discarded. This procedure was necessary not only from a technical standpoint but also from a mechanical one. The mill equipment would grind neither the hard over-burned clinker nor the hard under-burned stone. The grinding equipment was fashioned on the same principle as a grist mill, utilizing millstones made from the quartz pebble conglomerate or "grit" of the Shawangunk Formation. The growth of the natural cement industry fostered a sizable millstone business. The rocks in the Rosendale district are so intricately folded and faulted that natural cement raw materials crop out almost everywhere. Repeated exposures are clearly indicated by the many abandoned mines in the region and it is obvious that the early miners knew what to look for. The natural cement rock was at first quarried but eventually it became necessary to drive headings and open a mine where the dip carried the desired rock below the surface. To aid visibility, it was customary to mine down dip a certain distance, return to the outside, and create a similar new opening 30 feet or so along the strike. These headings would then be worked at right angles until they were connected. The procedure was repeated again and again, leaving a series of adits, which provided the light to work with, separated by 30-foot pillars. As it became necessary to penetrate deeper underground, illumination was provided by kerosene torches and the miners copied from their successful adits the scheme of leaving 30-foot pillars to support the roof. This room and pillar arrangement is clearly demonstrated in the Century Cement mine.
Natural cement production in the United States grew from 100,000 bbls. a year in the 1830's to 10,000,000 bbls. per year in 1899. At the peak of the industry, in the Rosendale district, some 20 plants employed 5,000 men and turned out 4,000,000 bbls. per year.
About 1894, portland cement, a carefully controlled blend of cement raw materials to insure uniformity, came into general use. In 1900 production of natural cement and portland cement was identical, 8,500,000 barrels each. During the early 1900's, the first large structure of its type to be entirely constructed with portland cement was the Boonton Dam in New Jersey. The Boonton Dam was to be a part of the water supply of Jersey City and Rosendale natural cement was originally specified for its construction. However, a director of the Alpha Portland Cement Company was a member of the Board of Water Supply and he proposed to supply the Jersey City job with portland cement from his company at the same cost as Rosendale natural cement. The dam was built with portland cement. Then portland cement gained ascendency over natural cement and by 1910 natural cement production throughout the United States was reduced to about 1,000,000 bbls. The plants began to close down after the start of the 20th century and by 1920 only one plant remained in the Rosendale district - Century Cement. In fact, this company is the only producer of natural cement in the United States today and that on a limited basis. The natural cement produced in the Rosendale district is a low lime, high silica, high magnesia, hydraulic cement of pozzolanic properties. A typical chemical analysis of the raw cement rock (Rosendale Member of the Rondout Formation) mined by Century Cement is:
SiO2 | 17.5
Al2O3 | 5.0
Fe2O3 | 2.8
CaCO3 | 41.5
MgCO3 | 31.5
Alkalies | 1.7
| 100.0%
The working faces are now about half a mile from the mine entrance and slightly more than 100 feet below the surface. Production is presently limited to the Rosendale Member.
A significant portion of the mined-out lower level has been leased for the underground storage of vital records. Construction of vaults and other preparations are in progress.

C: MIDDLE AND UPPER DEVONIAN CLASTICS OF THE CATSKILL FRONT, NEW YORK
The Middle and Upper Devonian of the Catskill Mountains region of southeastern New York consist of approximately 8000 feet of strata which commence with limestones at the base and grade upward through black shales, gray siltstones, gray sandstones, red beds, and, at the top, conglomerates (Fig. 3). The lowermost 2000 feet (Onondaga, Bakoven, and Ashokan Formations) are described by Chadwick (1944, p. 94-116). The purpose of this field trip is to examine the red bed-gray sandstone and conglomerate facies or depositional phases (Rickard, 1964) that have been referred to as "Catskill."*
*Rickard (1964) calls the conglomerate phase "Pocono."
FRANK W. FLETCHER
Susquehanna University

C: MIDDLE AND UPPER DEVONIAN CLASTICS OF THE CATSKILL FRONT, NEW YORK

STOP 1. (15 minutes) Onondaga Limestone (Middle Devonian).
This is primarily a stop for introduction to the basic Middle and Upper Devonian stratigraphic sequence of the Catskill Mountains region (see p. C1-C8). The Onondaga at this locality consists of very cherty, fossiliferous limestone. It dips toward 258° at 13°0 and forms a low escarpment. An excellent panorama of the chief physiographic elements of the region can be observed from this location. The topographic depression directly west of the Onondaga escarpment is Bakoven Valley, which is underlain by the relatively soft black shales of the Bakoven Formation. The low Hoogeberg range west of Bakoven Valley is composed primarily of resistant siltstones of the Mount Marion Formation and is capped by the Ashokan Sandstone. The plain beyond the Hoogebergs is underlain at its most easterly part by the upper Ashokan Formation and at its westerly edge by red beds of the Plattekill Formation. Towering above all of these elements is the Catskill Front; and, beyond, the high peaks of the Catskills including Slide Mountain, Wittenberg Mountain, and Cornell Mountain, whose summits are composed of the Slide Mountain conglomerate (Fig. 4).

STOP 2 (60 minutes) Manorkill and Gilboa Formations.
Buses will allow field trip participants to disembark and then will drive to top of section. Participants will walk along right (north) side of highway to top of section. CAUTION: Road is narrow, so "cling" to side.
The upper part of Kaaterskill Creek can be seen approximately 0.2 miles northeast of this locality. This is the location of Prosser's classic example of stream piracy, where the headwaters of Schoharie Creek were captured by the much-steeper gradient Kaaterskill Creek.
Figure 13 describes the stratigraphic section of this stop. Many of the typical rock types and sedimentary structures of the lower Catskill facies can be observed here. Especially note-worthy are the fining-upward cycles discussed on page C1.

STOP 3 (90 minutes) CONTINENTAL SEQUENCES IN THE PROXIMAL GENESEE GROUP
LUNCH (40 minutes) Guest Lecture by PETER J.R. BUTTNER Computing Center, University of Rochester
Follow NYSGA trail markers along rim of Catskill Front to outcrop of the "Twilight Park Conglomerate." CAUTION: Watch your footing along the Front. Please remain at least five feet back from the edge of the cliff. NO SPECIMENS MAY BE TAKEN FROM WITHIN THE PARK BOUNDARIES.
Trail lies on strata of the lower Oneonta Formation. Note crossbedding, excellent jointing and joint-controlled face of the Catskill Front. An excellent view of the Hudson Valley, the low Taconics, and, on very clear days, the Berkshires is available from the Front.
Return along trail to buses and field trip headquarters.

D:UPPER SILURIAN-LOWER DEVONIAN STRATIGRAPHIC SEQUENCE, WESTERN MID-HUDSON VALLEY REGION, KINGSTON VICINITY TO ACCORD, ULSTER COUNTY, NEW YORK
The remarks concerning the Upper Silurian and Lower Devonian stratigraphic units described in this paper largely pertain to strata within the Field Trip area (Fig. 1) extending in a belt from Accord (Stop 9) northeast to just beyond Kingston (Stops 1 and 2). The entire belt appears to be underlain with angular unconformity by a disrupted sequence of graywackes and shales to the northeast (Austin Glen affinity) and shales and siltstones to the southwest (Snake Hill affinity). The relations of these two lithologic groups in this area are not clear but it does seem that both were somewhat uplifted and folded (if not faulted) during the Taconian Orogeny; by latest Middle Silurian (?) the Ordovician sediments and structures were eroded to a surface of seemingly low relief or uniform slope. Subsequently a sequence of conglomerate (Shawangunk), shale (High Falls), sandstone (Binnewater) and carbonate (Rosendale-Wilbur) was deposited on the erosion surface in an apparent, general progress ion to the north east.
From Rosendale-Wilbur times through the remaining Late Silurian and Early Devonian the region was generally covered by marine waters, although intertidal and supratidal conditions existed intermittently on a local to regional scale. The Late Silurian and Early Devonian strata are relatively uniform in lithology and thickness throughout the area but some local and regional differences in depositional environments are evidenced within the Rondout, Thacher, Connelly and perhaps other formations. Apparent throughout the Rondout-Lower Devonian sequence is a more or less rhythmic alternation of variously interrelated, high energy-low energy, clay-carbonate, "shallow water"-"deep water", marine environments of deposition.
RUSSELL H. WAINES
S. U. N. Y. College at New Paltz
FLORENCE GROSVENOR HOAR
Winthrop, Maine

D:UPPER SILURIAN-LOWER DEVONIAN STRATIGRAPHIC SEQUENCE, WESTERN MID-HUDSON VALLEY REGION, KINGSTON VICINITY TO ACCORD, ULSTER COUNTY, NEW YORK

Toll Booth, NYS Thruway Interchange 17 (Newburgh).
Proceed north (right) onto Thruway toward Albany. Between Newburgh and New Paltz occur occasional road cuts in Ordovician (Martinsburg-Snake Hill (?)) slates and siltstones. Note the generally progressive decrease in degree of foliation of the beds northward.

NY 299 overpass near NYS Thruway Interchange 18 (New Paltz).
North of New Paltz the degree of foliation in several extensive road cuts in the Ordovician shales is much less pronounced than further south. A fauna found in Ordovician beds north of New Paltz shows affinities with that of the Snake Hill Shale (Late middle Ordovician).

Wallkill River
Wallkill River cutting Ordovician shales and siltstones on the right.

Rondout Creek cutting Ordovician shales and siltstones.
Rondout Creek cutting Ordovician shales and siltstones. Lefever Falls (rapids) on the left. This is about the northernmost extent of Ordovician outcrops along the Thruway in the field trip area (Fig. 1).

Underpass NY 32.
For the next 5.3 miles there are intermittent outcrops and road cuts in a more or less regularly ascending order of formations from Kalkberg (Lower Devonian) through Onondaga (Middle Devonian). High speed traffic does not permit close observation.

Esopus Creek.

Extensive road cuts
For the next 2.1 miles are extensive road cuts in gently dipping siltstones and shales of Mt. Marion Formation (Middle Devonian).

Mt. Marion (?) outcrop north of road and east of creek.
Bridge over Esopus Creek.

STOP 1: Road Cuts
STOP 1a: Road Cut in Esopus and Schoharie Formations. Pull off onto north side of highway with care. On this trip (Stops 1A-C) do not cross over onto south side of highway because of high speed traffic. Observe anticlinal exposure of upper (40-45') of Esopus Shale to the west and synclinal exposure of Schoharie Formation to the east. Contact between the two formations is covered but contacts, lithologies and thicknesses of the Carlisle Center, (including Black Bed), Aquetuck and Saugerties Members of the Schoharie can be observed. Fossils are best collected from the Saugerties Member. Sections of the feeding burrow Zoophycos cauda-galli are common in the Esopus Shale and Carlisle Center Member. Total extent of road cut is about 0.3 miles. Proceed east on foot along north side of highway right-of-way about 0.5 miles to the next stop.
STOP 1b: Road Cut in Glenerie, Port Ewen, Alsen and Becraft Formations: In this anticlinal exposure a partial section of Glenerie Formation and complete or almost complete sections of the Port Ewen and Alsen Formations can be closely examined on the western flank. A partial section of Becraft Limestone is exposed in the core of the structure. Although the contact between the Glenerie and Port Ewen Formations is covered, the Connelly Sandstone which intervenes to the south does not seem to be present here. The Port Ewen-Alsen-Becraft contacts are well-exposed. Some fossils can be collected in the Glenerie, Alsen and Becraft Formations. This road cut extends about 0.1 miles.
Proceed east on foot along north side of highway right-of-way about 0.2 miles to the next stop.
STOP 1c: Road Cut in New Scotland, Kalkberg, Ravena and Thacher Limestones: In this road cut a sequence of west-dipping beds are exposed. From west to east these are: the New Scotland Formation (incomplete); the Kalkberg Limestone with its two members, the Broncks Lake and Hannacroix (complete); the Ravena Limestone, sole representative member of the Coeymans Formation (complete); and the Thacher Limestone, sole representative member of the Manlius Formation. The Thacher-Ravena-Kalkberg and possibly Kalkberg-New Scotland contacts are well-exposed. Fossils can be collected from all formations or members, but especially the New Scotland Formation. The brachiopod Gypidula coeymanensis is noteworthy in the Ravena and Hannicroix limestones but is difficult to obtain whole. Stromatoporoids are noteworthy in the Thacher Limestone.
This road cut extends about O. 1 miles.

STOP 2: Wilbur, Austin Glen, Roundout, Thacher, Revena fms
STOP 2a: Road Cut Exposing Wilbur Limestone - Austin Glen (?) Graywacke Angular Unconformity: Because of high speed traffic please do not cross highway on this trip. Here is exposed a slightly folded, but largely horizontal, bed of Wilbur Limestone (lowermost member of the Rondout Formation) in distinct angular unconformity with underlying graywackes of possible Austin Glen affinity. It is possible that the unconformity is actually a fault but the same relations obtain too often elsewhere to make this likely. Some fossils may be extracted from the Wilbur Limestone. Coenites is abundant locally.
Proceed with care on foot south along NY 32 about O.1 miles.
STOP 2b: Road cut, Austin Glen (?), Rondout, Thacher and Ravena Formations and Members with Structural Complications. Watch for falling rocks. This road cut extends for the next 0.3 miles. Starting from the north end there is a stratigraphic succession from Austin Glen (?) through Ravena Limestone which is somewhat complicated in the north half of the cut by faulting. Individual stratigraphic units are well exposed but Figure 4 should be consulted in order to verify their structural relations. The following Formations or Members are present and their lithologies and contacts (/) indicated:
Ravena ls./Thacher ls./Whiteport dol./ Glasco l./ /Rosendale dol./Wilbur ls.?Austin Glen (?) graywacke
A few fossils may be collected from all units except perhaps the Whiteport and Rosendale dolomites and the Austin Glen (?). Especially noteworthy are Cystihalysites and stromatoporoids in the Glasco limestone.

Intermittent Outcrops and Road Cuts
From the south end of STOP 2b (39.4 miles) south to the intersection of NY 32 and US 9W (42.3 miles) there are intermittent outcrops and road cuts in a more or less regularly ascending stratigraphic order from Austin Glen (?) through Onondaga Formations. The overall picture is somewhat complicated structurally. Of especial note however, is a two to three foot bed of Connelly Sandstone exposed at the south end of a road cut on the east side of the highway about mile 40.6 of this trip. Traffic does not permit close observation from a bus.

Trailways bus depot. Rest Stop.

STOP 3: City of Kingston Wilbur Gravel Pit
Standard Reference Section of the Rondout Formation and Type Section of the Wilbur Member; Intercalation of the Wilbur Member with Rosendale Member; Binnewater Sandstone disconformably underlying the Rondout Formation and overlying the Ordovician Austin Glen graywackes and shales in angular unconformity. Walk up road to gravel pit (northeast) about O.1 miles. The cliff to the northwest is formed of an extensive sequence of Upper Silurian and Lower Devonian strata (mostly carbonates) partly repeated by faulting. Rickard (1962, p. 30) suggested that the standard reference section for the Rondout Formation be located in this quarry and Hoar and Bowen (1967, p. 4) designated this locality as the type section for the Wilbur Limestone Member which here inter-tongues with the Rosendale Member (Fig. 2). Disconformably underlying the Rondout Formation is the Binnewater Sandstone which is absent further north (STOP 2a, 2b) and which, at the present stop, overlies graywackes and shales of Austin Glen (?) affinity with angular unconformity.

STOP 4: Road Cut NY 32, Bloomington Vicinity; Glenerie, Connelly and Port Ewen Formations:
Here is exposed an almost continuous sequence of northwest-dipping beds of the upper part of the Port Ewen Formation (up hill) through the Connelly Sandstone into the lower part of the Glenerie Formation (downhill). The Connelly Sandstone has thickened considerably from the two or three foot exposure about one mile south of Stop 2a. Layers of abundant brachiopods exposed in section can be seen in the Glenerie limestones but collection in the round will prove difficult.

STOP 5: South End Quarry Hill
Binnewater Sandstone - High Falls Shale - Shawangunk Conglomerate - Snake Hill ? Sequence: Examine the disturbed siltstones and shales of Ordovician Snake Hill (?) aspect then examine the northwesterly dipping partly covered sequence of beds between the quarry and the edge of the mine pit to the west. Don't crowd edge of pit! From west to east the formations present are: Binnewater Sandstone (partly covered), Highfalls Shale (largely covered), Shawangunk Conglomerate, Snake Hill (?) shales and siltstones. The Binnewater-High Falls contact is covered but the High Falls-Shawangunk-Ordovician shale contacts are fully exposed. Noteworthy is the two to three foot thickness of Shawangunk Conglomerate and its relatively dark color (typical of the top of the formation locally). Also of note is the first two or three feet of shale beneath the conglomerate. This shale seems to differ from more typical Ordovician shales which underlie it. The mine pit to the west is excavated in a fault-complexed body of Rosendale Dolomite. The far wall (west) of the pit from bottom to top reveals a normal sequence of Glasco Limestone (ledge), Whiteport Dolomite (lower portion mined out) and lower part of the Thacher Limestone (upper part of the cliff).

Abandoned natural cement kilns on roadside to right.
Turn sharp left into open field and head toward distant kilns to the west by following dirt road left then right.

STOP 6: Fourth Lake; Rosendale Member Type Section
Fourth Lake; Rosendale Member Type Section; Ordovician, Snake Hill (?) Shale, High Falls Shale; Rondout Formation; Thacher Limestone (part) Sequence:
Park in front of kilns. Walk uphill to the right (north) over a glaciated shale outcrop of Snake Hill (?) affinity, then bear northwest over rubble pile and continue west at top of hill to New York Central Railroad tracks. Total distance is about O.1 miles.
Walk north right about 0.05 miles along track to railroad cut in Ordovician shales of Snake Hill (?) affinity. Retrace steps south about 0.07 miles along west side of track examining soil of covered interval for first signs of red shale particles (High Falls). Because traces of the Shawangunk Conglomerate are lacking and because the formation is not exposed locally, it is assumed that the High Falls Shale is in direct contact with the Ordovician shales even though the contact is covered at this Stop and not exposed locally. Continue walking south to the partly covered contact between the High Falls Shale and the Binnewater Sandstone. For the next O.1 miles in the railroad cut along the west side of the track is exposed a continuous sequence of northwest-dipping strata including uppermost High Falls (north) through Binnewater, Rosendale, Glasco, Whiteport and lower Thacher (south) members and formations. Examine the various units in light of general descriptions in the text. Contacts between units should be observed - some with caution. Except for pillars the bulk of the Rosendale and lower Whiteport members has been mined out. Please do not fall into the pits. Hoar and Bowen (1967, p~ 4) has designated this locality the type section of the Rosendale Dolomite Member of the Rondout Formation.

STOP 7: Williams Lake
Williams Lake; Rondout Formation; Binnewater Sandstone; High Falls Shale; Shawangunk Conglomerate Sequence: For the next 0.1 miles north in the railroad cut on both sides of the track is exposed a continuous sequence of westerly-dipping strata which include the Whiteport (south) through Glasco, Rosendale, Binnewater, High Falls and Shawangunk (north) members and formations. The various units and their contacts (where exposed) should be examined in light of general descriptions in the text. The Shawangunk Conglomerate, apparently absent at Stop 6, is well-developed here as well as locally, but the Shawangunk-Ordovician angular unconformity is not exposed.

Rosendale Hill lies directly ahead.

Century Cement Company natural cement kilns on right.
These are still in occasional operation.

Extensive cliffs on right are formed by New Scotland Formation.

STOP 8: High Falls, NY 213 Road Cut
High Falls Shale - Shawangunk Conglomerate Contact: Examine slightly anticlinal, light-colored exposure of Shawangunk conglomerate along extent of road cut (about 0.05 miles). Note the High Falls - Shawangunk contact at the east end of the cut (uphill) and determine whether it is distinct, conformable, gradational and/or interbedded. Note the dark color of the uppermost conglomerate layer.

Delaware and Hudson Canal
Sign on right noting the discovery of natural cement at nearby Bruceville in 1818. Just ahead is a section of the Delaware and Hudson Canal. The recently formed (1966) Delaware and Hudson Canal Historical Society plans to restore to operating condition some of the canal locks at High Falls. The canal played an important part in the transportation of natural cement and coal in the latter half of the nineteenth century.

High Falls and Central Hudson generating facilities on the right.
The face of the falls is formed of the Glasco Limestone and Rosendale Dolomite members of the Rondout Formation. Extensive exposures of Binnewater Sandstone and High Falls Shale occur from the base of the falls downstream.

Outcrops and Road Cuts
Outcrops and road cuts for the next 0.4 miles reveal a succession of strata from the New Scotland Formation (north end) through the Whiteport Dolomite in the bed of Kripplebush Creek at mile 62.5 (south end).

STOP 9: Abandoned New York, Ontario and Western Railroad Cut at Accord
Glasco Limestone (part), Rosendale limestones and Bossardville ? Formation (Accord Shale) Sequence: Walk a short distance southeast over abandoned road and descend into abandoned railroad cut. Walk to east end of cut. Walk west in cut and observe the following sequence: stromatoporoidal limestone of the Glasco Member overlying highly calcareous Rosendale member (compare with Rosendale at Stops 2, 6 and 8) which contains a highly arenaceous unit at the base and which overlies a laminated soft-weathering argillaceous dolomite and dolomitic shale (compare with Binnewater Sandstone and thin interbedded shales at Stops 6 and 7). The argillaceous, dolomitic beds here are tentatively assigned to the Bossardville Formation. They have also been referred to as the Accord Shale (Fisher, 1960). Extent of cut is about 0.1 miles. Time permitting, visits may be made to nearby quarries in the Rosendale limestones and in the Thacher and Ravena limestones.

Quarry in Rosendale limestones
On left is entrance to quarry largely excavated in Rosendale limestones. Road skirts northwest side of quarry.

Outcrop of Shawangunk Conglomerate on left.

Ascend the Shawangunk Mountains
Begin ascent of the general dip slope of the Shawangunk Mountains. For the next 6.1 miles the Shawangunk conglomerates and orthoquartzites which, in effect, sheath the Shawangunk Mountains, crop out extensively giving rise to typical Shawangunk Mountain topography.

Ordovician shales of Snake Hill (?) aspect
Ordovician shales of Snake Hill (?) aspect on the right. This exposure is part of an Ordovician shale window in the Shawangunk Conglomerate. Several years ago a very deep, very dry, wildcat was drilled in this window.

Lowermost part of the Shawangunk Conglomerate
Bridge underpass. Lowermost part of the Shawangunk Conglomerate is exposed in the road cut just east of the bridge.

Begin descent
Exposure of Ordovician shales of Snake Hill (?) aspect to the left. View of the Mid-Hudson Lowlands to the east and on a clear day, the Hudson Highlands to the southeast. Begin descent of Shawangunk Mountains.

Eastern face of Shawangunk Mountains
Shear cliffs of the eastern face of Shawangunk Mountain cuesta tower on the left, capped by almost two hundred feet of conglomerate and orthoquartzite. These cliffs are much used for practice in mountain-climbing as they present most, if not all grades of climbs. On weekends and holidays the cliffs are well populated with climbers from many states and Canada. The sport is not without risk; at least two climbers have "come off" here in the last three years.

Ordovician shale and siltstones of Snake Hill (?) affinity.
Proceed northeast through countryside underlain by Ordovician shale and siltstones of Snake Hill (?) affinity.

E:GEOLOGIC STRUCTURE OF THE KINGSTON ARC OF THE APPALACHIAN FOLD BELT
The Appalachian orogen when observed in its areal extent from Alabama to Newfoundland shows in its pattern a series of arcs, some bowed northwestward toward the foreland, others bowed inward toward the eugeosynclinal belt. One of the more prominent of these arcs, bowed eastward and southeastward toward the crystalline core of New England, is located at Kingston, New York, its hinge-zone being situated in the old Rondout and Wilbur districts of the City of Kingston. The western extremity of the arc lies in the vicinity of Rosendale, and in its northern extension continues to the environs of East Kingston and the Kingston-Rhinecliff Bridge on the Hudson River.
The type of deformation evident within the Kingston Arc may be of some interest to the structural geologist and the purpose of this field trip is to observe the geologic structure at several localities where exposures are favorable.
GEORGE R. HEYL, S. U. N. Y. College at New Paltz
MORRIS SALKIND, Saugerties High School

STOP I: The Nytralite Quarry on Route 32
STOP I: The Nytralite Quarry on Route 32 is developed in the Esopus Shale. The operations of this company extend on both sides of the highway. Shale is trucked from the quarry floor to the crushers on the ridge of Fly Mountain, where the material is processed. It is then heated in the kiln, causing the shale to expand. A conveyer leads down the south side of Fly Mountain, where the expanded shale is loaded on barges in Rondout Creek to be carried down the Hudson River to markets in the New York City area. Trucks are used to carry the expanded shale to customers in the Mid-Hudson area.
Though the Esopus Shales are not highly resistant to erosion, in this area they commonly are minor ridge-makers. Where exposed, they show as massive blocks whose bedding is difficult to follow, but whose cleavage is readily apparent. The cleavage may therefore be easily mistaken for the bedding in an outcrop.
Both the cleavage and the extensive fracture pattern in the shales is reflected in details of the topography of the region. The strongly-cleaved shales are more easily eroded and the intersection of the cleavage with the accompanying joints results in the appearance of gently sloping planes dipping in various directions where the shales are exposed (Fig. 1 - The vertical lines indicate cleavage).
Where freshly exposed, the shales appear black, blue-black, or olive-brown. Often they show vertical white bands, a result of re-deposition on their cleavage surfaces of some of the minerals dissolved from the shale.
Weathering of the shales will often bring out color changes that emphasize the bedding planes. Occasional lenses or thin layers of other material, e.g., sand, help in the delineation of the bedding. Where the shales have been exposed to weathering, some of those having a greater lime content will show a grayer surface.
At this locality the beds are generally more gently dipping than the cleavage. The response of the shales to folding was not paramount; they show some flexures, but the continued impress of the deforming forces caused the shales to shear rather than to fold. Shear planes present in some cases cut across the cleavage. Where a conjugate set of shear fractures exist they are parallel to the cleavage (Fig. 3). The cleavage is generally parallel to the strike of the beds. However, it should be evident that strike joints will generally merge with the strong cleavage.
Occasional fossil shell fragments can be found in the shales. Nodules of pyrite are frequent.

STOP II: Callanhan's Quarry and Railroad Cut
STOP IIa: Callanhan's Quarry is in the village of Connelly south of Rondout Creek. From the quarry floor, facing northeast, approximately 170 feet of limestones have been exposed by the quarrying operation. There are three areas or"pits" where the quarrying operations take place all at varying distances from the northwest-southeast section line drawn across the quarry floor. In the accompanying section, the pits are labeled by number (Fig. 5).
The limestone, commercially known as "traprock", is crushed to different sizes after being blasted from the walls of the quarry. It is used primarily in various kinds of construction such as road metal for highways, and concrete aggregate for building construction. The Rondout Creek is used to transport bulk shipments of the material.
The limestones show three major high-angle reverse faults cutting through all the beds exposed in the quarrying operation. There are numerous smaller faults. Looking to the southeast, one can see near-vertical faces of limestone. Bedding-surface slickensides are commonly seen in the quarry, for example, between the Alsen and Becraft units and within the New Scotland limestones.
The exposed southeast side of Pit I shows an extensive slickensided surface over much of its length. Also on this same surface and extending for many feet parallel to the slickensides are thick, rod-like mullion structures. The limestones in this pit are gently folded.
In Pit 2 there is an extensive fault zone which includes a major fault. Toward the southeast the quarry wall is near-vertical and shows extensive slickensides. There the beds are bent in a circular arc at the southeastern end of this section, and are folded synclinally.
The sharp folds are continued into Pit 3. Here the Becraft-New Scotland exposures are near vertical and show extensive slickensiding within the New Scotland beds.
STOP IIb: This stop is in the cut of the West Shore R.R. about one quarter mile east of Callanhan's Quarry. Near the road coming from the floor of the quarry to where it intercepts the railroad track there are exposures of the Hudson River sandstones. The contact of the Ordovician sandstones and the Silurian is not visible here. The Kalkberg and New Scotland beds can be seen just west of the railroad right-of-way. The Becraft limestone outcrop, to which an abandoned wagon trail leads, was mined in earlier years at this site. Many of the abandoned quarries in the Kingston area formerly exploited the Becraft or the Rondout limestones.
Of the quarrying operations the main evidence is a 100-foot shaft situated between the New Scotland and the Alsen through which the Becraft was removed. At the lowest part of the north wall in this shaft one can see part of the synclinal fold in the Becraft, which was also visible from the floor of Callanhan's Quarry. The railroad cut farther northward exposes the Port Ewen limestone (and its time-correlative deposits - the Connelly). The Port Ewen alternates with the Glenerie in exposures along the railroad tracks.

STOP III: Road cuts along Route 199 three miles north of Kingston.
This stop will be made along that section of Rt. 199 extending between Rt. 32 to Rt. 9W. Along Rt. 199 the road cut exposes relatively gentle folding in the Devonian beds (Fig. 6). There are two low concealed areas in the section which are covered by swamp deposits and alluvium.

Angular Unconformity
Approximately one quarter mile south of the entrance to Rt. 199 on Rt. 32 there is a good exposure of the angular unconformity between the Ordovician beds and overlying Silurian limestone.

STOP IV: Glenerie Falls
This stop is at Glenerie Falls and Rt. 9W approximately 6.3 miles north of Kingston. A plan view of the shear structures and the cleavage in the Glenerie Formation in this area is included (Fig. 4). The pattern which is shown in the plan view is seen as a side view where the Glenerie is visible along the highway. Some of the Glenerie exposures along the highway reflect the shear pattern so that the exposed blocks show as rectangles at times pointing toward the highway and at other times away.
The Esopus Creek which upstream meanders through its valley for several miles turns sharply to the east at Glenerie Falls and then flows north again at the foot of the Falls. Beyond, it continues between the confining Esopus Shales and the Glenerie, and has an approximately straight course almost to its mouth; it makes a bend at Saugerties and flows into the Hudson.
The rocks at the Falls clearly express the shear structure in the area. The weak, overlying Esopus Shales are being rapidly eroded. The presence of the Falls indicates a relatively youthful expression of the topography for the falls have not yet been planed down to grade.

F: STRUCTURE AND PETROLOGY OF THE PRECAMBRIAN ALLOCHTHON AND PALEOZOIC SEDIMENTS OF THE MONROE AREA, NEW YORK
The area covered by this trip lies in the northern part of the Monroe 7 1/2′ quadrangle, New York, and consists of a folded and faulted complex of autochthonous Precambrian gneisses, Lower Cambrian through Middle Devonian sediments and allochthonous Precambrian gneisses. Geologic maps covering the trip area have been published by Ries (1897), Fisher, et.al. (1961), and Jaffe and Jaffe (1962). Unpublished maps prepared by Colony and by Kothe (Ph.D. thesis, Cornell Univ.) undoubtedly contain valuable information but are not available for study. Recent workers in adjacent areas include Dodd (1965), Helenek (in progress) and Frimpter (in progress), all in the Precambrian autochthon, and Boucot (1959) and Southard (1960) in the stratigraphy and paleontology of the Paleozoic sediments. The work of Colony (1933), largely unpublished, is impressive.
HOWARD W. JAFFE, University of Massachusetts
ELIZABETH B. JAFFE, Amherst, Massachusetts

F: STRUCTURE AND PETROLOGY OF THE PRECAMBRIAN ALLOCHTHON AND PALEOZOIC SEDIMENTS OF THE MONROE AREA, NEW YORK

STOP 1: Bellvale Graywacke
The outcrop is on Oreco Terrace, just above the intersection of NY 208 and Oxford Road. Here, the Bellvale graywacke of the Hamilton Group (Middle Devonian) is exposed in a section approximately 220 feet thick. It consists of 20-40 foot beds of dark blue-gray, green-gray, or gray, fine-to medium-grained (.08-.25mm-avge. grain size) lithic arenite or graywacke, rhythmically interbedded with thin beds of dark green-gray to blue-gray shale. A representative modal composition of the graywacke follows:
| |
Detritals | |
| quartz | 20%
| oligoclase | 2
shale
phyllite
44?
siltstone
chert
9.0
| greenstone | 15
Matrix | |
clay, sericite,
chlorite, Mn oxide
15?
Metamorphic | |
| Chlorite | 2
| Muscovite | 1
| | 100%
Texturally, the rock consists of angular, elongated slivers of detrital quartz and predominantly phyllitic rock fragments (.08-.25mm) set in a fine matrix of sericitic muscovite, clay, and chlorite. It is often difficult to distinguish smeared-out phyllitic fragments from balled-up micaceous matrix, both of which frequently blend or flow together. Depending upon the uncertainty of the matrix content, or the classification used, the Bellvale is either a low-rank graywacke (Krynine, 1948), a subgraywacke or a lithic graywacke (Pettijohn, 1957) or a graywacke (Folk, 1954). Larger bent grains of chlorite and muscovite in the matrix, are here interpreted to have grown from fine matrix material, marking the beginning of the chlorite zone - greenschist facies of regional metamorphism imprinted during the Appalachian orogeny.
In general, the Bellvale graywackes tend to show rhythmic interbedding with shale, with graded bedding low in the section and strong current cross-bedding higher in the section. Occasional brachiopods are found low in the section; plant fossils are found higher up. Both features suggest a gradation from marine to nonmarine depositional environment. The provenance was a low-rank metamorphic or sedimentary terrane.
The shattered outcrop at Oreco Terrace is at the southwest corner of Rotated Block 8 (Fig. 2) and lies near the intersection of four directions of faulting. Attitudes of prominent structures at the outcrop are tabulated:
| Strike | Dip | Plunge
Bedding | N 67 W | 30 NE |
Cleavage | N 50 E | 37 SE |
Fault Slickensides | N 13 E | Steep W | 45 N
Fault Slickensides
N 38 E
Steep W
60 N
N 30 W
52 SW
39 W

STOP 2: Shawangunk Conglomerate
Spring Glen Golf Range: Shawangunk Conglomerate
The Shawangunk conglomerate and quartzite (Greenpond conglomerate unit) of Lower to Middle Silurian age occurs in a series of small outcrops extending northeastward along the western edge of the Shunemunk Mountain syncline. At this stop the Shawangunk forms a small, relatively inconspicuous topographic knob as contrasted with its occurrence near Stop 5, where the same unit forms the spine of the steep, southeast-facing escarpment of Lazy Hill. At the present stop the Shawangunk consists of about 75% buff pebble conglomerate intercalated with 25% fine-grained green-gray quartzite.
The conglomerate consists of white pebbles of milky vein quartz (averaging 15-40mm in length) in a matrix of finer pebbles and grains of rounded quartz, all cemented by secondary silica and buff-orange-red ferric oxides. Occasional pebbles of white orthoclase are present as are black pebbles consisting of a mixture of green tourmaline and quartz. The color of the weathered surface of the outcrop varies from pink (hematite) to yellow-brown (goethite) or black (manganese oxide dendrites) with some greens contributed by lichens.
The pebbles, obviously well-rounded when deposited on the Late Ordovician erosion surface, have taken on a secondary angularity and elongation due to stretching, crowding, rotation, and slippage in bedding planes produced during Paleozoic orogenies. Most of the pebbles show maximum elongation parallel to the fold axis (b-direction) and modest elongation parallel to the bedding (a-fabric axis). Many of the pebbles have been corrugated and a large number are cracked and sliced parallel to the b-c fabric plane. Bedding surfaces are slickensided, fluted, and warped parallel to the a-axis (down-dip). The fine-grained, gray-green interbedded quartzite is composed of quartz and minor orthoclase cemented by authigenic quartz, muscovite and chlorite, and Fe-oxides.
The elongation and shattering of the pebbles here and at Lazy Hill to the southwest greatly exceeds that observed in pebble beds in Lower and Middle Devonian rocks (Connelly conglomerate of Oriskany age, and Bellvale graywacke, respectively) in this area, suggesting that the Shawangunk was involved in an additional deformation episode of possible pre-Oriskany age. A pre-Acadian, Silurian deformation period in New York was reported by Megathlin (1939) and discussed by Kay (1942). The sporadic outcrops of Shawangunk quartzite to the north along the western limb of the Schunemunk Mountain syncline are all heavily silicified and sheared, again much more so than quartzites of Oriskany and Bellvale age.
The conglomerate and quartzite outcrop is S-shaped, with the attitudes of the bedding and a cross-fault as follows:
| | Strike | Dip
Bedding, Cgl. | North end of hill | N 8 E | 77 E
Bedding, Cgl. | North center of hill | N 59 W | 70 NE
Bedding, Cgl. | Center of hill | N 27 W | 50 NE
Cross-fault
N 77 W
90
Bedding, Qtz.
South end of hill
N 2 W
60 E
The cross-fault displaces the stratigraphically higher Shawangunk quartzite member to the west, putting it on strike with the lower conglomerate member of the Shawangunk Formation. On first viewing the outcrop, the alternating coarse pebble beds and fine feldspathic quartzites lead one to suspect that the beds are overturned. On close inspection this does not appear to be the case.

STOP 3: Museum Village Klippe
Museum Village Klippe: Allochthonous Pre-Cambrian Leucogneiss Resting On Cambro-Ordovician Wappinger Dolomite
From the Old Mansion Road cut in the Precambrian Museum Village klippe, look south across the N 75° W-trending Quickway crossfault. The ridge due south is the Bellvale synclinal extension of Schunemunk Mountain. The next ridge to the west is Lazy Hill, held up by Shawangunk conglomerate, and offset from the Golf Range Shawangunk conglomerate of Stop 2. To the west of Lazy Hill, the next prominent ridge is the Goose Pond Precambrian klippe, formerly continuous with the Museum Village klippe and now offset about 2 miles along the Quickway cross-fault.
Museum Village klippe is a thin, synclinal, saucer-shaped slice of gray-white albite-quartz-microperthite leucogneiss that has survived five or six orogenies. The rocks of the allochthon were deposited as a clastic wedge (molasse) in a reducing environment, perhaps as long ago as 1500 million years; they were folded and metamorphosed to the sillimanite-almandine-orthoclase metamorphic grade about 1100 million years ago; thrust from the east in Taconic or Late Ordovician time; refolded and faulted in Taconic time; possibly again in Acadian time; refolded and faulted in Appalachian time; and finally shattered by Triassic block faulting and associated block rotation. In outcrop, the leucogneiss is heavily shattered and slickensided with lineations often running in three directions at a given place. Quartz grains and pebbles are stretched into thin corrugated tongues and sheets showing elongations of 15:1 and 20:1 parallel to the b- and a- fabric axes. Over most of the outcrop, biotite and garnet are extensively retrograded to chlorite, and abundant calcite veinlets cross the rocks at all angles.
Towards the central and western part of the cut there occur occasional thin layers rich in fresh biotite and uncommonly coarse laths (not needles) of fresh blue-gray sillimanite that have survived the complex orogenic history. As none of the Cambro-Ordovician or younger rocks in the area show any metamorphic grade higher than chlorite zone metamorphism, the sillimanite is assumed Precambrian in age, and its preservation in large fresh grains in an otherwise extensively retrograded outcrop is remarkable.
The original sedimentary record of Precambrian deposition is preserved in graphite-rich quartzitic layers and in microscopic placer layers rich in apatite, zircon, sphene and ilmenite. In places, volcanic rocks associated with the sediments may be represented by amphibolites such as those in the Bull Mine Mountain klippe to the north.
Modal analyses of samples collected along an east-west traverse across the Museum Village klippe follows:
| East Side | Center | West Side
Andesine (An 32)
-
36.0
32.4
Quartz
Biotite
Almandine-pyrope | 0.1 | 2.0 | - | -
Tourmaline | - | + | + | -
Zircon
+
Ilmenite
The presence of albite in the most retrograded gneisses of this and the other allochthonous Precambrian blocks studied fairly consistently suggests that it may be a retrograded mineral after an originally more calcic plagioclase. The K-feldspar in all of these rocks is microperthite (usually microcline microperthite) and is indicative of a temperature of Precambrian metamorphism of the order of 660° C. The presence of two plagioclases, one as free grains and the other exsolved in microcline microperthite, is characteristic of many of the granitic gneisses of both the autochthon and the allochthons. In some of the allochthonous leucogneisses, the microperthite and the albite tend to occur in separate bands which may reflect original compositional differences.
Park on Oxford Road and cautiously descend hill to the Quickway (N.Y. 17-West = U.S. 6). Beware of high speed traffic and stay close to the outcrop which parallels the highway. Walk to the extreme west edge of the roadcut where the Precambrian leucogneiss rests in overthrust contact on the light gray Cambro-Ordovician Wappinger dolomite. Note the occasional flat-lying, slippery fracture planes at the contact.
The metamorphic layering in the allochthon dips to the east whereas the dolomite bedding dips predominantly west. The average foliation of the leucogneiss is N 33 E,20 SE. The average attitude of the dolomite beds is N 22 W, 35 W. Prominent faults in the klippe parallel the metamorphic layering and trend N 22, E 20 SE. The fault contact of the dolomite and the klippe is irregular and has the same general attitude. Both the dolomite and the klippe are cut by vertical faults trending N 27 W.
Drive west along Old Mansion Road observing the flat topography superposed on the Hudson River pelites. These are more gently folded with increasing distance from the Precambrian allochthon.

Rolling folds in pelites
Cross the Quickway (N. Y. 17) overpass and bear hard left (east) on N.Y. 17-M. Drive about 1.1 miles east noting rolling folds in the Hudson River pelites. Road parallels Quickway fault.

STOP 4:Precambrian Allochthon
Goose Pond Mountain: Precambrian Allochthon Over Overturned Hudson River Pelite
Observe black, fissile Hudson River shales (Middle? Ordovician) in the road cut at the northwest edge of the Precambrian allochthon. Careful observation will show that the attitude of the bedding and cleavage is N 78 E; the bedding dips 70 S and the cleavage 40 S. This indicates that the outcrop is on the limb of an overturned fold with the synclinal axis to the north. The shales both here and at Bull Mine Mountain klippe to the north are all wildly folded and overturned close to the overriding Precambrian allochthons.
Many of the Hudson River black shales are calcareous, and consist of fine laminae (.05-.lmm) of dolomitic silt or mud (marl) intercalated rhythmically (occasionally cross-bedded) with carbonaceous shale. An estimated thin-section mode of a representative Hudson River "shale" follows:
Mineral | Calcareous laminae | Carbonaceous laminae
Detritals and matrix: | |
dolomite, calcite
30%
5%
plagioclase, microcline
10
+
mica, clay, chlorite | 15 | 50
carbonaceous matter, graphite
-
15
Metamorphic: | - | +
chlorite, muscovite, biotite | - | 5
In the woods about 100-150 feet southwest of the shale outcrop on N.Y. 17-M, moss-covered rubble of shale, dolomite, and "limonitized" fault breccia indicate where the covered contact has been crossed. The edge of the Precambrian allochthon of Goose Pond Mountain is found in place about 130 feet south from the road, and the first rock found in place is a graphitic calcareous quartzite of which sample No. 527 is representative.
Drive 0.4 mi. on N. Y. 17-M, stopping at a white albite-quartz-microcline microperthite leucogneiss (sample No. 20), in places graphitic, biotitic or rarely, garnetiferous. Note the extreme elongation and smearing out of quartz pebbles and grains similar to that seen at the Museum Village outcrop of Stop 3. Further to the east, the rocks become increasingly calcareous (sample No. 788). At the extreme eastern edge, prehnitized calc-silicate leucogneiss is interlayered with some amphibolite, the latter of probable basic volcanic origin. Modes of representative rock types of the Goose Pond allochthon follow:
Modes Of Gneisses Of The Goose Pond Mountain Allochthon
East Side
Center
West Side
Sample Number
Mineral | | | |
brown hornblende | 0.2 | 33.0 | - | -
Here, as in the Museum Village klippe of Stop 2, the greatest amount of retrograding occurs at the eastern and western margins of the allochthon with some fresh rock occurring near the center. If the klippen are indeed synclinal saucers the presently exposed centers of the masses would lie at a further distance from the sole of the thrust and would be expected to show less alteration. It should be emphasized that the Precambrian autochthonous gneisses in the southern part of the Monroe quadrangle (Jaffe and Jaffe, 1962) are not comparably retrograded except near the Triassic border faults.

STOP 5: Shawangunk Quartzite
Walk 0.2 mile west crossing buried northeast-trending fault contact between the Shawangunk ridge of Lazy Hill rising steeply ahead and the Bellvale ridge of Durland Hill to the rear. Walk to the north nose of Lazy Hill (permission of the owners, the Durlands, is necessary) where a large outcrop of Shawangunk quartzite is exposed. The rock is a thin-bedded, pink, buff and white orthoquartzite consisting of:
Mode of Shawangunk Orthoquartzite, Durland Property
Quartz | 93%
Chert
Sericite, Chlorite
Zircon | +
Hematite | +
Goethite | +
Pyrite | +
Green Tourmaline | +
| 100.0%
The quartz grains are well-rounded, moderately elongated, well-sorted (average diameter, 0.75mm), and the rock is very tightly cemented. Each grain of quartz is cemented to another by authigenic quartz overgrown in optical continuity with the detrital cores. Undulatory extinction due to deformation passes through both the core and overgrowth of each grain. The Lazy Hill ridge top to the south (not visited) is formed of a coarse white pebble conglomerate interbedded with white orthoquartzite (occasionally ripple-marked) and grades eastward to a red arkosic conglomerate below the ridge-top. Quartz pebbles and orthoclase pebbles are strongly elongated (3:1 and 4:1) and heavily shattered and veined in both the red arkosic and the white conglomerate.

STOP 6: Connelly (Oriskany) -Esopus Contact
The outcrop at Monroe Bowl-0-Fun consists of about 300 feet of the Esopus Formation underlain at the rear of the cut by red and white pebble conglomerate, the Connelly Conglomerate of Oriskany age. Here, the Connelly consists of weathered, yellow, "limonitic" conglomerate (3' or more), succeeded by white to buff, pebble-bearing orthoquartzite (5'), which is in turn overlain by bright red hematitic quartzite (10'). The pebbles in the Connelly conglomerate are of white, round to slightly elongated quartz, averaging 1-2 mm in maximum dimension. The Connelly is disconformably overlain by a lowermost member of the Esopus Formation, recognized by Southard (1960). The attitude of the bedding of both the Connelly and the Esopus at their contact is N 68 E, 45 N. A heavily slickensided fault surface, trending N 53 E, 60SE cuts across the Connelly beds and presumably also cuts the overlying Esopus Formation.
The lowermost member of the Esopus, at its base, consists of fissile, blue-gray siltstones which weather to brown and orange on cleavage surfaces. Many of the rocks are marked withTaonurus cauda-galli on bedding planes. At this outcrop the authors have collected a remarkable fauna including a specimen of the giant trilobite,Coronura myrmecophorus, not previously reported from the Esopus Formation. According to D.W. Fisher, New York State Paleontologist who identified the specimen, it has previously been reported from the Schoharie and Onondaga Formations. The specimen was donated to the N. Y. State Museum collection.
The lowermost member is also relatively rich in conulariids, none of which have yet been identified. Other fauna include the brachiopods:Leptocaelia flabellites, Schuchertella sp, Acrospirifer macrothyris, as well as some chonetid and orbiculoid genera. Platyostomid and loxonemid gastropods, rugose corals and a dalmanited trilobite were also collected by the authors.
The lowermost member grades into the black, poorly fossiliferous Lower Mudstone member which in turn grades into a purple sandstone at the north end of the 350 foot exposure. The sandstone is presumably the lower part of the Highland Mills member of the Esopus Formation. The fauna of the lowermost member at the Bowl-O-Fun appears to differ significantly from that of the Highland Mills member of the Esopus Formation found at Bakertown and Highland Mills (described by Boucot, 1959). The fauna should receive some serious study by specialists before the outcrop is demolished by new construction.

STOP 7: Poughquag Quartzite (Lower Cambrian)
Orange Turnpike: Poughquag Quartzite (Lower Cambrian)
Walk 0.16 miles due west over hilltop to the edge of a cliff formed by a 10 foot section of the Poughquag Formation (Lower Cambrian). The section consists of alternating 2 inch to 2 foot thick beds of ferruginous orthoquartzite, conglomerate, and arkose, striking N 75 W and dipping 80 N, overlying the vertically dipping Precambrian autochthon with marked angular unconformity. This represents original sedimentary onlap with only gentle warping or folding in subsequent geologic time. Apparently the Precambrian Monroe Massif (Block 2) was sufficiently rigid throughout the Paleozoic to prevent the deformation of the overlapping embayment of Poughquag quartzite and Wappinger dolomite. This is indicated by both the gentle warping observed and also by the relative sphericity of the quartz pebbles in various Poughquag beds.
Several of the beds are feldspathic, a feature uncommon in the Poughquag of the Poughkeepsie quadrangle (Gordon, 1911). One such bed at the Monroe outcrop is a conglomeratic arkose which is a true high rank arkose in the sense of Krynine (1948). A remarkable textural feature of this rock is the abundance of authigenic feldspar (microcline?) which is the principal cementing medium in sample No. 466. The specimen consists of 1-2mm quartz and microcline pebbles (all very round) lying in a matrix of 0.2mm grains of microcline and much less quartz. The microcline grains, each with a dirty outline (Fe and Mn oxides), tend to float in the matrix of authigenic microcline (?) cement which is clear in appearance. Some sawtooth or hacksaw terminations on the detrital microcline cores (Edelman and Douglas, 1931) indicate that interstratal solution has taken place after deposition, presumably in situ. The authigenic feldspar overgrowths show only weak twinning when grown around detrital cores showing strongly developed microcline twinning.
A mode of such rock is as follows:
Mode Of Lower Cambrian Poughquag Conglomerate Arkose
Specimen No. 466
Microcline
47.4%
Microcline microperthite
+
Quartz | 48.6
Albite-oligoclase | +
Muscovite | +
Rutile, Anatse, Tourmaline (green and brown) | 0.5
Zircon | 0.5
Hematite, Mn oxides | 3.0
| 100.0%
The mineralogical composition of the Poughquag at Monroe leaves little doubt that it was derived from erosion of the granitic gneisses it overlies.
On the return walk to the road, stops may be made at exposures of post-Wappinger lamprophyre dikes which the authors believe to be of Late Ordovician age (Jaffe and Jaffe 1962). The authors have studied the dikes in considerable detail and would suggest a possible age of intrusion similar to that of the ultramafic intrusion of the Cortland Complex at Stony Point, New York (Ratcliffe, 1967). The Cortland Complex has been dated by Long and Kulp (1962) at 435 million years by K/ A isotopic ratios obtained on biotite from the complex, a date close to the accepted Ordovician-Silurian boundary.

G: THE PLEISTOCENE GEOLOGY OF THE WALLKILL VALLEY (2)
G.GORDON CONNALLY
S.U.N.Y. College at New Paltz

G: THE PLEISTOCENE GEOLOGY OF THE WALLKILL VALLEY (2)

STOP 1: Ablation Till
Examine the ablation till exposed in the cut behind the Carrol's stand. Compare this till to the lodgment till exposed at Stop A-2 on trip A. There will be a discussion of weathering profile and soil development.

Cross the Catskill Aqueduct
The aqueduct follows the road on the right for 1/2 mile until it is re-crossed. After re-crossing the aqueduct note the lithology of the stone walls, particularly the absence of Shawangunk boulders.

Ascend the till ridge that trends north-south.
This is a ridge of drumlinized crests that can be traced for about 10 miles east of the Wallkill Moraines.

Flat-topped outwash deposit
This road traverses a flat-topped outwash deposit that has a 400 foot crest on the distal side of the Wallkill moraines. This suggests that the ice occupied the Wallkill position during the development of the 400 foot lake level.

Outermost Wallkill Moraine
Ascend the gentle distal slope of the outermost Wallkill Moraine and then descend the proximal slope into the stagnant ice complex.

Cross the first inner Wallkill Moraine.

STOP 2: Wallkill Moraines
STOP G-2. Here can be seen some of the Wallkill Moraines. Their possible relationships and the relation of the Wallkill River to the glacial deposits will be discussed.

The Wallkill Moraines are well displayed on the right

Second inner Wallkill Moraine
Cross the distal slope of the second inner Wallkill Moraine. This moraine is on a bedrock escarpment and is not nearly as massive as the topography makes it appear. The State Prison Moraine (?) is on the left in the distance.

Cross the Catskill Aqueduct.

A striated bedrock knob is exposed on the right.

State Prison Moraine
The State Prison Moraine (?) is immediately adjacent to the road on the left and will be crossed in the vicinity of Ireland Corners.

Splendid panorama
On a clear day a splendid panorama can be viewed on the left. In the foreground is the Lower Wallkill Valley with the Shawangunk Mountain cuesta in the distance. The Catskill Mountains can also be observed on the skyline behind, and north of, the Shawangunks.

STOP 3: Delta remnant
Leave the cars and walk through the field on the left to the sand pit. Examine the relationship between pro-glacial lakes, deglaciation, and the present course of the Wallkill River. This deposit is the remnant of a delta formed in the final 230 foot lake in the Wallkill Valley.

Floodplain of the Wallkill River
The floodplain of the Wallkill River can be seen on the left. The floodplain evidently extends only to the low escarpment a few hundred feet west of the River with undisected lake plain from the scarp to the west valley wall.

Old stone houses
This street contains the old stone houses for which New Paltz is famous. These stone houses were built by the Huguenots in the late 1600's and early 1700's.

Oxbow Lake
As the road bends right and then left it is following an abandoned meander of the Walkill that now exists as an Oxbow Lake. This oxbow may be seen behind the houses to the left.

Lake shoreline
From this point to Stop G-4 Route 32 follows the shoreline of the 230 foot lake. This may explain the frequently exposed bedrock along the east side of the road.

Bedrock channel on right, lake sediment on left
Route 213 joins from the right just south of the bridge over the Wallkill River. Note that the Wallkill is cutting a bedrock channel to the right while flowing over lake sediment on the left.

STOP 4: Wallkill geomorphology
Here will be discussed the geomorphology of the Wallkill River drainage basin and its relation to the Rosendale sand plain.

Descend from sand plain
Descend from 240' on the sand plain to 65' in the Rondout Creek Valley. Bridge across Rondout Creek.

Channel bars
Note the channel bars in the creek; these did not exist before the recent drought.

Cross a remnant of the 200 foot Lake Albany (?) plain.

Fly Mountain fault scarp.
Bear left on Mountain Road and parallel the Fly Mountain fault scarp.

STOP 5: Wilbur gravel pit
This is the Wilbur gravel pit of the City of Kingston. It is the type locality for the Wilbur limestone member of the Rondout Formation (Silurian). Leave the cars on the road and walk up into the pit to examine the relationship between the ice-contact gravels and the slumped, overlying Lake Albany (?) sands, silts, and clays. Examine the pebble lithologies and compare them with those at Stops A-1, A-6, and A-8 on Trip A.

Lake Albany (?) clays crop out on both sides of the Thruway.

Cross Rondout Creek cutting a bedrock channel at this point.

Cross Wallkill River cutting bedrock channel at this point.