NYSGA 1968
NEW YORK STATE GEOLOGICAL ASSOCIATION GUIDEBOOK
TO
FIELD EXCURSION
S 40TH ANNUAL MEETING
1968
AT
QUEENS COLLEGE
CITY UNIVERSITY OF NEW YORK
FLUSHING, NEW YORK

A: BEDROCK GEOLOGY IN THE VICINITY OF WHITE PLAINS, NEW YORK
By Leo M. Hall, University of Massachusetts
(Approved for publication by the Assistant Commissioner for the New York State Museum and Science Service.)
INTRODUCTION
Stratigraphic relations, including two unconformities, are well displayed by the bedrock in the White Plains quadrangle in Westchester County, New York. Fifteen rock units within the traditional "New York City Group" have been mapped in detail there. At the lower unconformity, Cambrian Lowerre Quartzite or Inwood Marble rest on Precambrian Fordham Gneiss and Yonkers Gneiss. Along the upper unconformity, the lower member of the Manhattan Schist rests on various units of the Inwood Marble as well as the Fordham and Yonkers. In addition, a major thrust fault may occur near the base, and locally at the base, of what has traditionally been mapped as Manhattan Schist.
There is widespread evidence for at least four, and probably five, phases of deformation in the region. The Yonkers Gneiss and Fordham Gneiss were folded at least once before the deposition of the Lowerre Quartzite and younger rocks. The pre-Manhattan rocks were deformed, at least mildly, prior to the deposition of the lower part of the Manhattan Schist. A major thrust fault, correlated with Taconic thrusting, may separate member A of the Manhattan Schist from members Band C of the Manhattan Schist. Finally, all of the rocks and previously formed structural features were involved first in major nappe-like isoclinal folds and second in folds with steeply dipping axial surfaces.
The main purpose of this field trip is to illustrate the stratigraphy of the region. In doing so, some of the main structural features will also be shown.

A: BEDROCK GEOLOGY IN THE VICINITY OF WHITE PLAINS, NEW YORK

Inwood Marble
The road log begins at the northbound New York Thruway exit in Ardsley and the route is indicated on Figure 2. The contact between member B and member C of the Inwood Marble is exposed along the west (left) side of the exit ramp. Member C is exposed along the east (right) side of the ramp as well. The Inwood here is in the west limb of a north-plunging syncline with Manhattan Schist in the trough of the syncline underlying the hills on the east and Fordham Gneiss under the hills on the west. Leave the exit ramp and turn right (north) onto route 9A (Saw Mill River Rd.) and then proceed northward along the west limb of the syncline.

Manhattan Schist
Turn right (east) onto Ashford Ave. and proceed southeasterly over the hill, across the synclinal trough. The exposures along the roadsides are Manhattan Schist.

Sprain Brook valley
Ashford Ave. enters Sprain Brook valley which is underlain by Inwood Marble. The ridge ahead to the east is Fordham Gneiss in the center of a north-plunging anticline. There are some small exposures of Lowerre Quartzite along the west limb of the anticline in this vicinity. The gneiss plunges out at the anticlinal nose less than a mile north of here.

West Limb of Anticline
Turn right (south) on Sprain Rd. and proceed southwesterly along the west limb of the anticline. The unpublished field notes of E.C. Eckel (New York State Museum and Science Service, Geological Survey files) report Lowerre Quartzite and Fordham Gneiss behind the houses on the east (left) side of the road but, apparently due to construction, only quartzite float exists there now.

STOP 1. New road cuts on Sprain Brook Parkway Construction site.
The road cuts are along the left (north) side of Jackson Ave. on the approach to the new Jackson Ave. bridge that is now under construction and along the west side of the southbound lane of the Sprain Brook Parkway which is also presently under construction. We will walk north along the southbound lane of the Parkway and be picked up by the bus at Ardsley Rd. Those not wishing to walk may reboard the bus here and ride to Ardsley Rd. Be careful of traffic on Jackson Ave. when disembarking.
Start at the west end of the road cut on the approach to the new Jackson Ave. bridge; in traversing eastward several varieties of rock types in the Fordham Gneiss will be seen in the center of the north plunging anticline. Minor structural features are abundant and many of the linear elements plunge northward apparently parallel to the anticlinal axis. Although this area has not been mapped in detail, it appears that these rocks might be grouped into three mapping units from west to east as follows:
1. Brown to rusty weathered sillimanite-garnet-biotite gneiss and smaller amounts of gray biotite-quartz-feldspar gneisses.
2. Light gray, locally pinkish, biotite-quartz-feldspar gneiss with sparse garnet. This rock looks somewhat like the Yonkers Gneiss in places.
3. Dark gray biotite and/or hornblende gneiss and amphibolite.
It would be necessary to map this area in detail to determine whether or not the above subdivision is meaningful.
After traversing to the west end of the new Jackson Ave. bridge, walk northward along the deep road cuts in subdivision 3, proposed above, and down into the Sprain Brook Valley. Walk north along the west side of the valley to Ardsley Rd. and observe several road cuts in subdivision 3. Drilling data obtained at several places along the Grassy Sprain Valley in conjunction with the highway construction now in progress reveal the predicted presence of Inwood Marble beneath the valley fill.
The contact between dark gray biotite gneiss and light gray to pinkish-gray gneiss is exposed in the road cuts at the west end of the new Ardsley Rd. bridge which is now under construction. This contact projects into the Sprain Brook Valley where it is truncated by the Inwood Marble along an unconformity. The west contact of the light gray or pinkish-gray gneisses has been mapped in detail here and it is truncated by the Inwood Marble approximately three quarters of a mile north of here. Reconnaissance indicates that these gray gneisses are very likely the same as subdivision 2 proposed above.

East Limb of Anticline
Turn left (north) onto Grassy Sprain Rd. and proceed along the east limb of the anticline. The road is near the contact between the Inwood Marble and Manhattan Schist. The hills to the east are underlain by the Manhattan in the trough of a syncline.

Manhattan Schist Member B
Turn left (northwest) onto Ardsley Rd. (A good exposure of member B of the Manhattan Schist is in the road cut along Ardsley Rd. approximately 0.1 mile southeast of this intersection.) Proceed northwest along Ardsley Rd. entering the floor of Grassy Sprain Valley.

Crossing anticline
The bus will stop here in order to allow the group to board and then will continue northwesterly on Ardsley Rd. crossing the anticline.

Recrossing the syncline
Proceed straight through the dangerous intersection where the street name changes from Ardsley Rd. to Ashford Ave. Continue northwesterly on Ashford Ave. re-crossing the syncline.

Have traversed Manhattan, Inwood down into Fordham Gneiss
Proceed through the major intersection and onto the bridge that overpasses the Saw Mill River, New York Thruway, New York Central Railroad tracks, and the Saw Mill River Parkway. In so doing we have traversed from the lower part of the Manhattan Schist through members A, B, and possibly part of C of the Inwood Marble down into the Fordham Gneiss.

Fordham Gneiss Member A
Many exposures of member A of the Fordham Gneiss are present in the hills on the west (left) side of Northfield Ave.

Cyrus Field Rd., named after "the father of the first transatlantic cable".

STOP 2. Harriman Road Reservoir.
Park in the driveway on the right (north) side of the road that leads into the watershed area of the reservoir. We have been allowed to visit this area through the courtesy of the Village of Irvington, Department of Public Works. This is a water supply reservoir, please conduct yourself in accordance.
This is the area of a steeply plunging structural syncline that is defined by the contacts between various members of the Fordham Gneiss (Figure 3). Minor structural features and the orientation of foliation indicates that the syncline plunges 50° to 60° toward the south. It has been possible to map a separate amphibolite within member B of the Fordham Gneiss here (Figure 3) but the amphibolite cannot be separately mapped elsewhere. We will study the syncline by traversing along and across the amphibolite-garnet gneiss contacts (see walking route, Figure 3). Disembark from the bus and proceed southeast along the northeast side of Harriman Rd. to station a.
Station a - Dark amphibolite and biotite-hornblende gneiss along with some garnetiferous gneiss are exposed here on the east limb of the syncline. The contact between the amphibolite and garnet gneiss appears gradational here and it is very difficult to map the amphibolite separately from here south. The apparent gradational nature of this contact may be due to minor folds which are abundant here. Note the pyroxene (green-weathering) rimmed by hornblende (black) indicating retrograde metamorphism. Thin sections of similar rocks in member B of the Fordham reveal amphibole lamellae within the pyroxene and these lamellae are apparently retrograded exsolved pyroxene. The textural and mineralogical relations in this rock are open to various interpretations.
Station b - The exposure of typical gray garnet-rich gneiss in the trees on the north side of the road occupies the keel of the syncline here. Elsewhere in this rock type sillimanite is locally abundant, particularly as inclusions in garnet, but only traces of sillimanite have been observed here.
Station c - Dark amphibolite in steep south-plunging minor folds. Note the trend of the foliation here and then look toward the northeast corner of the reservoir where the amphibolite-garnet is present at station d. The strike obviously changes and this contact outlines a minor fold here on the larger syncline.
Station d - We have progressed northward along the west limb of the syncline and across the garnet gneiss-amphibolite contact. This outcrop of gray garnet gneiss is structurally beneath the amphibolite.
Station e - The garnet gneiss here is in the keel of the syncline. Note the foliation athwart the trend of the amphibolite-garnet gneiss contact. This foliation is apparently parallel to the axial plane of the syncline.
Station f - The amphibolite is in the keel of the syncline here and the foliation is parallel to the amphibolite-garnet gneiss contact. If time permits we will walk along the north shore of the reservoir across many exposures of rocks typical of member C of the Fordham Gneiss.
Station g - This is an exposure of member C of the Fordham Gneiss that here consists of biotite and/or hornblende-quartz-feldspar gneiss, with many quartz-feldspar layers, and amphibolite. These rocks are complexly deformed with many examples of refolded folds as well as boudinaged amphibolite.

Fordham Gneiss-Inwood Marble contact
Proceed north more or less along the Fordham Gneiss-Inwood Marble contact

Sunnyside
Turn left (west) onto the entrance road to Sunnyside (West Sunnyside Lane). Sunnyside is the former country home of Washington Irving who designed and remodeled the house himself and is responsible for its unique architecture.

Inwood Marble Member B
Member B of the Inwood Marble is exposed in the stream on the right (north) side of the road.

STOP 3. Sunnyside.
NO HAMMERING PLEASE!
The contact between the Lowerre Quartzite and member A of the Inwood Marble is exposed here. This same contact is exposed at STOP 2 on Trip H (Ratcliffe, this guidebook).
Sunnyside belongs to Sleepy Hollow Restorations, Incorporated. This is a non-profit organization that has allowed us free access to Sunnyside for purposes of this field trip. Visitors are normally charged an admission fee. Please show your gratitude by being careful.
Proceed through the reception center to the outlet of the pond, "Little Mediterranean". Lowerre is exposed in the brook beneath the bridge and extends upstream. Here, the Lowerre consists of typical tan to buff weathered quartzite, micaceous quartzite, feldspathic quartzite and granulite. More Lowerre is exposed downstream from the bridge and a large fold is clearly displayed at the waterfall. This fold is large enough to be outlined by the Lowerre-Inwood contact on the regional geologic map (Figure 1.). Bedding attitudes indicate that the fold plunges 60° to 65° toward the southeast. A white quartz vein one to two feet thick is present in the axial region of the fold.
The contact of the Lowerre with member A of the Inwood is exposed below the waterfall and the Lowerre is relatively clean quartzite near the top. The Inwood consists of coarse white dolomite marble and a few calcite-bearing beds are also present. A bright green chromium-bearing chlorite is locally present in the coarse white dolomites. Paleontologists have assured me that the siliceous "box work" present here does not represent organic remains.
There is a fine view of the Palisades across the Hudson River. The cliffs are marked by the Palisades Sill which is in contact with the Triassic Stockton Formation at the base of the cliff a little above the surface of the river (Figure 1). An unconformity, somewhere beneath the river, separates the Paleozoic and Precambrian rocks in the vicinity of Sunnyside from the overlying Triassic rocks. This unconformity dips westward and thus projects above the ground surface at Sunnyside. Evidence for the unconformity is clear in the vicinity of Stony Point on the west side of the Hudson River, see Figure 1, Trip H, (Ratcliffe, this guidebook).
There is at least one small exposure of member A of the Inwood on the grounds of Sunnyside. We will not visit the small exposures of member C of the Fordham that are present in the wooded area north of Sunnyside, but the unconformity at the base of the Lowerre must be present somewhere in the vicinity of the northern boundary of the grounds.

Fordham Gneiss Members A and B
Turn left (east) onto Ashford Ave. and proceed east across member A and member B of the Fordham Gneiss.

Fordham Gneiss-Inwood Marble-Manhattan Schist contacts
Start across the bridge that overpasses the Saw Mill River etc. and in so doing, cross the Fordham Gneiss-Inwood Marble-Manhattan Schist contacts.

West limb of syncline
Turn left (north) onto Route 9A (Saw Mill River Rd.) and proceed north along the west limb of a syncline.

Outcrops of Manhattan Schist are on the right (east).

STOP 4. REA Express Terminal.
This is a good exposure of rocks that are typical of member B of the Inwood Marble. It consists of interbedded gray and white dolomite marble; tan, cream colored, and locally pinkish-weathering dolomite marble; tan calc-schist and granulite. There are several north-plunging sinistral folds with half wavelengths of three to four feet outlined by beds in the vicinity of the corner of the cut and the side of the cut parallel to the east side of the building. These are interpreted to be later stage folds and evidence for an earlier stage of Paleozoic folding is revealed locally by folded mineral lineation. There are many other minor folds throughout the exposure. It is noteworthy that the syncline at STOP 2 is very close (Figure 3) and that its orientation is apparently unrelated to the folds present here. This suggests that the syncline at STOP 2 is a structural feature that was developed due to deformation in the Precambrian.
A zone of closely spaced fractures that dip 65° west is present at the corner of the cut. This is probably related to late (Triassic?) minor fault movement.

Inwood Marble Member B
Several exposures of member B of the Inwood Marble are along the right (east) side of the road.

Inwood Marble-Manhattan Schist contact.
Turn right (northeast) onto Route 100B and proceed northeast across the Inwood Marble-Manhattan Schist contact.

Inwood Marble in center of anticline
Turn left (north) onto Route 100A (Knollwood Rd. ). The broad valley to the northeast (right front) is underlain by Inwood Marble in the center of a south plunging anticline. Proceed northward along the west limb of this anticline.

Proceed east across the anticlinal valley.

Manhattan Schist Members A, B, and C
Large road cuts expose members A, B, and C of the Manhattan Schist on the east limb of the anticline.

Manhattan Schist Member C
The extensive road cuts on the left (north) side of the expressway expose member C of the Manhattan Schist in the trough of a south plunging syncline.

Inwood Marble contact with Fordham
The expressway overpasses the Bronx River Valley which is here underlain by Inwood Marble. We cross the Inwood-Fordham contact and proceed down through the upper limb and across the axial surface of an early stage nappe-like fold.

Fordham Gneiss and Yonkers Gneiss
Extensive road cuts expose multiply deformed Fordham Gneiss and Yonkers Gneiss in the core of the early stage fold.

Calcite marble and schist
A road cut on the right (south) side of the expressway exposes interbedded calcite marble and schist at the base of member A of the Manhattan Schist. The contact of these rocks with the Fordham Gneiss is essentially exposed here and is an example of a place where the Middle Ordovician rocks rest directly on Precambrian. We are on the lower limb of the early stage nappe-like fold which has been refolded into an anticline and we are here located on the west limb of this later stage anticline. The lower part of the Manhattan exposed here compares favorably with the fossil bearing beds at Stop 5 and Stop 7 on Trip H (Ratcliffe, this guidebook).

East limb of the later stage anticline.
All of this maneuvering has allowed us to cross the axial plane of the later stage anticline to the east limb but we remain on the lower limb of the early stage nappe-like fold. Proceed northward along the east limb of the later stage anticline.

Proceed along the west limb of the later stage anticline.

STOP 5. Silver Lake.
We are permitted to use this park through the courtesy of the town of Harrison. Please don't litter the area with trash.
An exposure of member A of the Inwood Marble is present near the entrance to Silver Lake Park. Walk northward along the east side of Silver Lake and, in so doing, proceed along the east limb of the northerly plunging later stage anticline and at the same time along the lower limb of the earlier stage nappe-like isoclinal fold. (Figure 4). The steep topography on the west side and at the north end of the lake is underlain by Fordham Gneiss and the ridge on the east by Yonkers and Fordham. We are located on the Paleozoic rocks and the contact at their stratigraphic base projects in the air above our heads so that the stratigraphy is completely inverted here. Walk to the north end of the lake where the hinge of the later stage anticlinal fold is located (Figure 4). Walk northward, up the hill and down the stratigraphic section through the Lowerre Quartzite into the Fordham Gneiss. Note that the bedding in the Lowerre dips northward and thus projects beneath the older Fordham. In walking up the hill we are proceeding across the lower limb of the earlier stage nappe-like fold and essentially along the axial trace of the later stage fold.
The Lowerre here consists of tan to brown weathering gray feldspathic granulite, tan-weathering quartzite and micaceous quartzite, interbedded half-inch to two-inch thick beds of white quartzite and feldspathic granulite. Brown to rusty-weathering feldspathic granulite and feldspathic schist with local sillimanite nodules characterize the basal Lowerre here. The Fordham consists predominantly of gray biotite-quartz-feldspar gneiss.
Minor structural features abound in these rock exposures. Most of the linear elements plunge at 40° to 60° northwestward and apparently are parallel to the plunge of the later stage anticline.

Lowerre Quartzite
There is an exposure of Lowerre Quartzite behind the milk plant on the northwest side of Silver Lake.

Axial surface of nappe-like fold
Proceed north across unexposed Fordham Gneiss and up through the axial surface of the nappe-like fold to the upper limb.

Exposures along either side of the road are Fordham Gneiss.

Kensico Dam
The rock facing on this dam is Yonkers Gneiss that was quarried from the hills to the east of the Kensico Reservoir called "Quarry Heights". Fordham Gneiss is at the east end of the dam, Manhattan Schist is at the west end and the Inwood Marble, though not exposed, is in between.

The New York City Water Supply aerators are on the right.
The aerators are gone, and the site is being used for fill.

Interbedded calcite marble and schist
Interbedded calcite marble and schist at the base of member A of the Manhattan Schist are exposed in the road cut on the right (northwest) side of the road.

STOP 6. United States Post Office in Thornwood.
Member A of the Manhattan Schist is exposed in the cuts alongside and behind the buildings. Characteristic gray and dark-gray sillimanite-garnet muscovite-biotite schist of member A is present here. Before the recent construction and paving, there was an exposure of interbedded white calcite marble and schist here. These rocks compare favorably with the lower portions of the Manhattan Schist that are to be visited on Trip H (Ratcliffe, this guidebook).

STOP 7. Exposures along the east side of Elwood St.
The exposures of member A of the Manhattan Schist behind the buildings as well as on the wooded slope consist of the typical fissile schist and some gray and white calcite marble beds. Definite interbedding of marble and schist cannot be proven here although there are at least two exposures that strongly suggest such a relationship.

STOP 8. Member E of the Inwood Marble.
Park beyond the United States Post Office at the end of the street. Walk south over the hill toward the Taconic State Parkway. An exposure of member E of the Inwood is on the west side of the hill along the east edge of the Taconic State Parkway. The contact between gray-weathering calcite marble (member D?) and tan-weathering calcite marble, typical of member E, outline a tight isoclinal fold.

Inwood Marble Member D
The large roadcut on the south side of the intersection is in member D of the Inwood and there are exposures of member E up on the hill south of the road cut. Proceed southward on Route 9A along the west limb of a syncline with Fordham Gneiss underlying the hills on the west and Manhattan Schist those on the east.

STOP 9. Member E of the Inwood Marble.
These exposures are typical of member E of the Inwood Marble and consist predominantly of tan and gray-weathering calcite marbles. Note the many northeast plunging folds.

Proceed southward continuing in the Inwood Marble.

Unconformity at the base of the Lowerre Quartzite
There is an excellent exposure of the unconformity at the base of the Lowerre Quartzite in a cut behind the A & P warehouses west of Route 9A. There are extensive exposures of Lowerre on the hillside extending all the way across the Saw Mill River Parkway to the west. Continue southward through Elmsford more or less along the Inwood-Manhattan contact.

STOP 10. Warburg Campus.
Park in the parking lot north of Woodlands High School. This 160 acre campus is a former estate of Felix Warburg that was given to the town of Greenburgh for educational purposes. The classroom buildings on the campus accommodate 3000 students from kindergarten through high school. We have been granted permission to visit this area by the administration of Greenburgh School District No.8.
The rocks here are at the nose of a southwest-plunging later-stage anticline (Figure 5). Evidence for two, and possibly three, phases of deformation is displayed by minor structural features. The contacts between amphibolite (member B of the Manhattan) and schist, schistose gneiss and granulite that are typical of member C of the Manhattan outline the fold (Figure 5). Note that member B is above the base of member C here.
Some areas of particular interest are indicated on the map (Figure 5) by lower case letters. The upper and lower contacts of the amphibolite are easily identified in the vicinity of point "a" where gray to brownish-weathering feldspathic garnet-muscovite-biotite schistose gneiss, gneiss and granulite with local white sillimanite nodules is below as well as above the amphibolite. Trace the contacts south-eastward by walking across the valley to exposures on the steep slope west of the classroom building in the vicinity of point "b" on Figure 5. The lower amphibolite contact is folded here and though there are several examples of the results of multiple deformation, a particularly fine example of a refolded fold is present near the north end of these exposures. Evidence for three stages of deformation is found here where the slip cleavage that deforms an earlier foliation appears to be folded.
Proceed southeast over the top of the hill where amphibolite is well exposed. An unusual occurrence of magnetite with white quartzfeldspar rims is present in the amphibolite on the southeast side of the hill. Many interesting minor structural features are present in the rocks on the hill in the vicinity of "c" (figure 5). Toward the north between the gym and the classroom building is an exposure of schist with particularly good examples of sillimanite nodules.

Inwood Marble Member B
Road cuts here expose member B of the Inwood Marble and a particularly good exposure of member B is present on the east (left) side of Route 9A between the Thruway overpass and the southbound Thruway entrance.

Manhattan C on the left (east).

Manhattan C on both sides of the highway.

Road cuts in the Fordham Gneiss.

Yonkers Gneiss on the left (East).

Fordham Gneiss is on the right (west).

Fordham Gneiss is on both sides of the highway.

Yonkers Gneiss
Yonkers Gneiss is exposed in the old quarry on the right (west) and there are active quarries in the Yonkers a little further west. This is in the area specified by Merrill (1890, p. 388) as typifying the Yonkers Gneiss.

Yonkers Gneiss
Yonkers Gneiss is exposed in a cut along the Thruway exit ramp on the left (east).

Highview Reservoir is on the left (east).

STOP 11. Type locality of the Lowerre Quartzite.
This is the type locality of the Lowerre Quartzite designated by Merrill (1896, p. 26). The portion of the Lowerre now exposed here is predominantly well bedded gray and tan-weathering feldspathic granulite and gray feldspathic muscovite-biotite schist that weathers tan to brown. Typical tan-weathering quartzite is present about forty to fifty feet above the base but is subordinate. It seems likely that more of the characteristic quartzite was exposed here when Merrill originally defined the Lowerre but that it has since been removed through the work of man. It also appears that Merrill used the modifier "quartzite" in the name Lowerre Quartzite because the most distinct rock types that characterize the assemblage of rocks in this formation are tan weathering quartzite and feldspathic quartzite.
The Fordham Gneiss beneath the Lowerre consists mainly of amphibolite with some gray garnet-biotite-gneiss. This is another place, similar to STOP 5, where the base of the Lowerre is "dirty". There are other places, such as the cut behind the A & P warehouses at mileage 36.3 (this field trip), where clean quartzite and feldspathic quartzite are directly in contact with Fordham.
The unconformity here is deformed into a series of northeast plunging sinistral folds. This is in accord with the map pattern in this vicinity (Merrill and others, 1902) which indicates the rocks here are on the west limb of a stratigraphic syncline.

B: CRETACEOUS DELTAS IN THE NORTHERN NEW JERSEY COASTAL PLAIN
By James P. Owens, James P. Minard, and Norman F. Sohl.
U. S. Geological Survey, Washington, D. C. 20242
(Publication authorized by the Director, U. S. Geological Survey.)
INTRODUCTION
In recent years there has been a growing recognition of the importance of deltaic deposits in many sedimentary basins. The extensive investigation of modern deltas has resulted in the isolation and description of many of the subenvironments of this very complex sedimentation system. On this field trip, some of the subenvironments of an ancient deltaic system will be examined.

B: CRETACEOUS DELTAS IN THE NORTHERN NEW JERSEY COASTAL PLAIN

STOP 1. Woodbridge clay of the Raritan Formation (Figure 8).
Section as follows:
5-10 feet of sand and gravel of the Pensauken Formation.
30-40 feet of interbedded sand and clay of the Woodbridge unit of the Raritan Formation. Numerous layers of siderite and iron oxide-cemented sand are present. Some sand layers contain marine fossils. Interpreted as prodelta-bottomset beds.
5-6 feet of sand and clay containing much wood. Some wood appears to be in an upright position. Probable marsh deposits.
20 feet of dark-gray clay which is weathered at the top. Possible lagoonal origin.

STOP 2. Sayreville Sand Member of the Raritan Formation (Figure 9).
Section as follows:
20-40 feet of cross-stratified sand exposed in the pit walls. Interpreted as channel-fill and spit facies.

STOP 3. Laminated beds of sand and clay of the Morgan beds
Laminated beds of sand and clay of the Morgan beds (Berry, 1906) in the lower part of the Magothy Formation (Figure 10). Section as follows:
15-25 feet of alternating beds of yellow-brown to light-gray micaceous quartz sand and clay. A considerable amount of carbonaceous matter is present throughout. Interpreted as natural levee deposits.

STOP 4. Magothy Formation
Magothy Formation overlain by several feet of Merchantville Formation and Pleistocene sand and gravel (Figure 11). Section as follows:
5-6 feet of Pleistocene silt, sand, and gravel.
5-6 feet of dark-greenish-black quartz-glauconite sand of the Merchantville Formation. Interpreted as prodelta to open shelf deposits.
8 feet of dark-gray clay with some sand partings.
12 feet of alternating dark-gray to black clay and light-gray quartz sand layers. Layers are about 1/4 to 1/2 inch thick. Pyrite nodules are present throughout.
12 feet of white to light-gray quartz sand with some lignite and clay layers. The above 32 feet of the Magothy is interpreted as top set and foreset beds.
1 foot of gray-black clay with light-gray quartz sand and siderite concretions (exposed at low tide). Fossils are present in the siderite. Interpreted as prodelta and bottomset beds.

STOP 5. Merchantville Formation
Merchantville Formation overlain by several feet of Pleistocene sand and gravel and spoil from the Woodbury Clay (Figure 12). Section as follows:
5-10 feet or more of Pleistocene sand and gravel and disturbed Woodbury Clay. Apparently was disturbed and intermixed during excavation or subsequent pushing aside.
20 feet, plus or minus, of dark-greenish and grayish-black sandy silt and clay and sandy clay of the Merchantville Formation. Contains abundant mica, glauconite, and layers of siderite. Interpreted as prodelta and bottomset deposits.
Several feet of the upper, weathered sand and clay layers of the Magothy can be seen near the entrance of the pit.

STOP 6. Upper Navesink Formation
Upper Navesink Formation overlain by lower part of the Red Bank Formation (Figure 13). Section as follows: 25 feet of the lower part of the Red Bank Formation (Sandy Hook Member). Mostly fine-to medium-grained quartz sand with considerable feldspar, much mica (green and colorless), and some glauconite, particularly in the base. The upper part of the section is weathered to brown, the lower part is dark-gray. Micro-fossils and small megafossils and shell fragments are abundant in the dark basal part, and this unit is more clayey and compact.
15 feet of greenish-black, clayey, glauconite sand of the Navesink Formation. Several shell beds are present. Exogyra, Pycnodonte, Ostrea, Choristothyris, and Belemnitella are common. (The total thickness of the Navesink is about 25 feet here).
These sediments are interpreted as open shelf marine deposits beyond the laminated prodelta beds. Except for the shell beds there is a lack of conspicuous bedding. The abundance of glauconite is suggestive of deeper water and more uniform sedimentation.

C: THE TRIASSIC ROCKS OF THE NORTHERN NEWARK BASIN
By E. Lynn Savage, Brooklyn College of The City University of New York
INTRODUCTION
Objectives of the Field Trip.
Outcrops to be visited on this trip have been selected to illustrate some of the problems involved in the interpretation of Triassic rock units and facies in the northern Newark Basin. (Figure 1). Where possible emphasis is directed toward general Triassic problems, as well as to those which are unique to the northernmost area of this basin.
Although it is generally accepted that much of the Triassic has been removed by erosion, there are two contrasting ideas as to whether the present northeastern end of the Newark Basin marks the former extent of the sediments:
(1) The present outcrop area is almost the same as the original extent (McLaughlin, 1957, p. 1498; Glaeser, 1966, p. 101).
(2) The sediments were once much more extensive, covering the area between the New Jersey-New York Trough and the Connecticut Trough (Sanders, 1963, 1960; MacLachlan, 1957, p. 13; Wheeler, 1938).

C: THE TRIASSIC ROCKS OF THE NORTHERN NEWARK BASIN

Southwest end of fault
Tunnel plaza and portal to north (left) are at southwest end of fault (Figure 12 A, B) cutting diagonally across Palisade Sill. Downdropped block is on east (right) side. There are many such faults along the Palisades.

Jointed diabase on left.

Regional erosion surface levels top of sill
Small park on right (east) commemorates duel between Aaron Burr and Alexander Hamilton. Regional erosion surface levels top of sill (Figure 13).

Olivine zone in Palisade Sill on left (see Figure 15A).

Stockton arkose on left
Metamorphosed rather well-sorted yellowish-gray to very pale orange Stockton arkose and overlying chilled border of sill on left.
Coarse-grained arkose at contact, locally cross-bedded with dispersal to S or SW, contains abundant plagioclase and orthoclase, some quartz, pale green diopside and vermiculite,. and minor sphene and talc. Fine-grained arkose within 12 inches of the contact consists mainly of albite, with minor vermiculite and talc, and a trace of chlorite.

Stockton arkose on left.

Large columnar joints with smaller joints in lower part of sill. Talus.

Stockton arkose and cliff of sill
Stockton arkose and cliff of sill on left (just south of Lever Brothers Research Center). Bedded, coarse to very coarse-grained arkose with 2-foot unit of tabular cross-bedding with dispersal to SW.

Well-bedded, very dark, fine-grained Lockatong hornfels.

STOP 1 Gorge and River Roads. Lockatong Hornfels
Gorge and River Roads. Lockatong Hornfels. Time here: 30 minutes. Park in lot of Celatex Corp. (Allied Chemical).
A composite section of Lockatong hornfels and interbedded stockton arkose is exposed in the excavation (watch for falling rock) on River Road (Figure 14A) opposite the Mobile Service Center and in the roadcut on the west side of Gorge Road (Figure 14B). This sequence (strike N 40° E, dip 15° W) consists of (1) about 18 feet of dark gray, well-bedded Lockatong hornfels in 3 well-developed cycles, overlain by (2) about 15 feet of bedded, rather well-sorted yellowish-gray Stockton arkose, which is in turn overlain by (3) about 50 feet of dark gray, well-bedded Lockatong hornfels below the Palisade Sill.
1. The asymmetrical cycles in the excavation are analcine-bearing "chemical" cycles like those found in western New Jersey and adjacent Pennsylvania (Van Houten, 1964, 1965). Because of their unique composition, these deposits were easily altered by isochemical thermal metamorphism. In contrast, the arkose 50 feet below the sill is virtually unaltered. In pattern, each cycle (Figure 14C) originally consisted of a lower very dark gray to black shaly to platy carbonate-rich feldspathic mudstone (converted to a biotite-albite hornfels) with thin laminae and local beds (1 to 3 cm) of calcite and dolomite, a middle platy carbonate-rich portion with abundant disruption by shrinkage, converted to a calc-silicate hornfels, and an upper massive analcine-rich argillite, now commonly with a splotched fabric produced by metamorphism to a biotite-albite-analacine hornfels.
2. The slightly metamorphosed arkose 50 feet below the sill consists mainly of plagioclase, orthoclase and quartz, some vermiculite, and a trace of talc.
3. Spotted Lockatong hornfels of a tetrital cycle within 5 feet of the sill consists mainly of biotite and plagioclase, some orthoclase and andalusite, and a trace of chlorite and magnetite. Lockatong hornfels 15 to 20 feet below the sill contains minor analcime.
The following additional accessory minerals have been found in this hornfels facies (Lewis, 1908, p. 136-147): pale green augite, apatite, cordierite, epidote, hornblende, sillimanite, scapolite, dark-green spinel, sphere, tourmaline, and vesuvianite.
The variations in mineral assemblages found here and in the Granton Quarry (STOP 8) resulted largely from differences in composition and amount of water present, and not from major differences in temperature and pressure.

Large xenolith of Lockatong hornfels
Large xenolith (15 feet by 30 feet) of Lockatong hornfels about 15 to 20 feet above base of sill, exposed behind Virginia Lee Lace Co. Baking produced coarse-grained biotite-plagioclase hornfels with chlorite, pale green and colorless pyroxenes, and more coarsely crystalline stringers of chlorite, biotite, calcite, diopside, albite and very pale green muscovite.

Sill exposed on left (west), hornfels in cut to east (right).

Lockatong hornfels below sill behind Edgewater Welding Co.

Stockton arkose and Lockatong hornfels
Stockton arkose and Lockatong hornfels behind Edgewater sewage treatment plant.

STOP 2. Palisade Sill and Lockatong Hornfels
Palisade Sill and Lockatong Hornfels along abandoned trolley route. Time here: 1 hour. Park on east side of Undercliff Avenue, opposite small park with 3 benches.
Traverse through Palisade tholeiitic diabase sill (Figure 15 A, B, C) - up (southwest) an abandoned trolley route along a brook, behind houses:
Lockatong Hornfels below sill, as at STOP 1.
Irregular cross-cutting contact (Figure 16A).
Xenolith 2 feet thick, 15 feet above base of sill; unusually coarse-grained biotite-plagioclase hornfels.
Olivine diabase, generally about 15 feet thick, 50 feet above the base at switch-back on trolley route. Dr. S. Bhattacharji will discuss its origin.
Normal diabase throughout the middle of the sill.
Upper coarse diabase with pegmatitic schlieren.
Upper chilled border.
Hypotheses proposed to explain differentiation of the diabase sill and to account for the layer of olivine diabase are:
1. Gravitational settling of early-formed olivine and later pyroxene crystals (F. Walker, 1940). Although widely cited as such, the Palisade Sill probably is not a good example of gravitational differentiation. -
2. Fractional crystallization (Figure VH 2, C) by ionic diffusion and convection circulation of magma, supplemented by minor gravitational settling of large olivine crystals (Hess, 1956, p. 1960).
3. Fractional crystallization, with late-stage injection of a new pulse of magma into the partially crystallized mush. Large olivine crystals concentrated by gravitational settling (K.R. Walker, 1962; 1967 in press).
4. Mechanical or hydrodynamic flow differentiation, with central concentration of early-formed olivine crystals during intrusion of the magma. Crystal mush then settled as a result of fluctuation of velocity and pressure (S. Bhattacharji, 1967).

Olivine zone halfway up cliff on left.

Olivine zone is at road level.

Outcrop of sill on right.

Phytosaur was found below the bridge
A phytosaur, Clepsysaurus (Rutiodon) was found in the stockton arkose below the bridge.

Outcrops of sill on both sides of road.

Outcrop of sill.

Outcrop of sill on left.

Outcrop of sill on right. Lipton Company on left.

Glacially polished diabase on right.

Jointed diabase on both sides of road.

Glaciated diabase on right

Stocton arkose, dikes
Along Hudson River at Sneden's Landing approximately 45 feet of light gray thick-bedded and locally cross-bedded Stockton arkose is interbedded with reddish-brown to pale lavender baked mudstone. Dispersal was to the northwest (Figure 11). Locally dikes of arkose have been injected into the mudstone. The arkose contains angular pebbles of quartz and pink feldspar as much as an inch in diameter; in contrast to sandstone found north of Piermont (and higher in the stratigraphic sequence) zircon, rutile and authigenic anatase are abundant, tourmaline and garnet are rare, and metamorphic rock fragments are absent (Savage, 1967).

Outcrops of diabase at entrance to Tallman's State Park. Olivine zone.

Sparkill Gap.
Sparkill (formerly Overpeck) Creek in the gorge is the only stream that flows eastward across the Palisade Sill into the Hudson River. Presumably it flows along a cross-fault (such as seen at Lincoln Tunnel plaza) that has offset the sill more than 900 feet westward on the north side.
According to Johnson (1931) the Hudson River originally flowed southwestward on the Schooley erosion surface above the position of the sill, was superposed on it and cut a water gap (Figure 17). Later a subsequent stream flowing on relatively non-resistant rocks east of the sill captured the ancient Hudson drainage by headward erosion. Overpeck Creek then reversed the original drainage direction. This explanation does not account for the coincidence of the gap and a cross-fault (see Thornbury, 1954, p. 234-240, for discussion of the problem).
Between Piermont and Nyack Beach State Park (STOP 3), there are many outcrops and abandoned quarries of "brownstone" which was used extensively for building-stone more than 50 years ago. Most of the rock is a dark brown to reddish brown well-sorted medium to fine-grained arkose, commonly interbedded with reddish brown mudstone. Some of the lighter colored arkose is coarser grained, but conglomerate is rare. Presumably these deposits are a gradational sequence between the uppermost part of the Stockton Formation and the lower part of the Brunswick Formation, and differ in heavy mineral content, sedimentary-metamorphic rock content and dispersal direction from those in the upper part of the Stockton Formation to the south (Savage, 1967, p. 34).

Glacial till overlying diabase on right.

More till on diabase on right.

Outcrop of diabase on left.

View of south end of Verdreitege Hook
View of south end of Verdreitege Hook (Hook Mountain) portion of Palisade Sill above Nyack Beach state Park.

Large glacial erratic on right, on lawn of library built of "fieldstone. "

South end of Verdreitege Hook with spectacular talus slope.
5 minute stop for photographs.
North of Nyack the Palisades are as much as a mile west of the Hudson River because the sill intruded a higher part of the west-dipping Newark sequence. Then it swings back to the river at Nyack Beach state Park, cutting across somewhat lower Newark strata (Figure 3). At its north end the intrusion is a dike that intrudes successively higher Brunswick beds (Figure 2) and turns sharply to the west almost perpendicular to strike; at its western end it completes a sickle-shaped arc. Diamond-drilling in a quarry at Little Tor near Haverstraw shows that the intrusion dips about 45° SW (Lowe, 1959).
A distinct olivine-rich zone is absent at the northern end of the Palisade intrusion as it is at its southwestern end in west-central New Jersey. Nyack Beach state Park.

STOP 3. Lower Brunswick deposits.
Nyack Beach state Park. Lower Brunswick deposits. Time here: 1 hr. 45 min.
LUNCH will be served after a 1 and 1/3 mile walk to outcrops in the lower part of the Brunswick Formation.
The Park authorities have made this convenient stop available to us. Do not disturb the foliage or the crops. Please collect specimens only in those areas where there has been recent blasting of ledges. Watch out for copperhead snakes, yellow-jacket wasps, poison ivy and poison sumac.
Traverse along footpath leading north from north end of parking area.
Distances noted below were measured from beginning of the path.
200': 15 to 20 feet of yellowish-gray arkose crop out 40 inches above the path.
895-950': Picnic tables; old quarry in reddish-brown mudstone and yellowish-gray arkose.
1450-1570' : Outcrop exhibiting rapid facies changes, especially at north and south ends:
7': Massive reddish-brown mudstone; cross-bedded; marked channelling. 8': Reddish-brown shale.
13' : Micaceous reddish-brown siltstone and shale; cross-bedded. Scattered pebbles of quartzite and quartz, and pieces of shales.
8': Reddish-brown shale.
2' 0 Massive reddish-brown mudstone. Path level
2215-3745': More talus; columnar joints in diabase. Note sinuous joint surfaces. Pass fireplaces.
3745-3925': Tree-clad slope.
4040-4405': Outcrop near open stone shelter:
10': Massive light gray arkose, locally cross-bedded.
2': Reddish-brown mudstone.
4': Thin-bedded, pale reddish-brown arkose, interbedded brown mudstone.
8': Massive, tough light-gray arkose, rare cross-bedding and coarse layers with pebbles of angular quartz as much as 2 1/2 inches in diameter, pieces of feldspar as much as 1 inch long and intraformational mudstone clasts.
Path level.
Continue along winding path. Diabase above is conspicuously jointed. Sing-Sing prison across river to east.
5571-6039': At south end diabase is at path level. Rises to north to reveal contact with arkose which has not been metamorphosed more than a few feet from the sill. Beware of yellow jacket nests in brush near this contact.
6039-6080': Cover beyond retaining wall 10 feet of cross-bedded light-gray arkose overlies reddish-brown mudstone.
6445-6465': Arkose with rare gray limestone and quartz clasts to 1 inch in diameter; pink feldspar to 2 inches in diameter, and rare pebbles of pegmatite.
6570': Arkose in large block is cross-bedded, contains clasts of quartz, red sandstone, pink feldspar, shale, mica schist, and relatively abundant almandine garnet.
6575': Excellent outcrop extends northward for about 1000 feet. Exhibits rapid facies changes and variety of sedimentary features characteristic of fluvial sedimentation (Figure 18A). N62W, 13° W.
5': Yellowish-gray arkose with large scale channeling and cross-bedding.
6': Interbedded yellowish-gray arkose and reddish-brown mudstone. Unit pinches out to north.
11': Reddish-brown to lavender mudstone with irregular upper contact. Cross-bedding, with scour and fill, burrowing, mudcracks, and ripple marks (2 inch crests, N68W), as well as load and flute casts. Interbedded with layers of medium to coarse-grained micaceous reddish-brown arkose grading (Figure 18A) into lensing buff and lavender arkose with pebbles of limestone and feldspar. The lower part of the mudstone also contains pebbles of quartzite, quartz and feldspar. About 5 feet above the base at the south end of the outcrop a greenish-gray layer consists largely of rounded grains of silty mudstone. Some may be Paleozoic lithic grains, but many with concentric structure, elongate shape and calcite cores apparently are intraformational mud pellets.
6580': Very coarse arkose with angular quartz as much as 1 inch in diameter, pieces of shale parallel to bedding, and clasts of limestone and feldspar, interfingers with reddish-brown mudstone.
6665': Well-developed tabular cross-bedding, rare in Newark rocks in Rockland County.
6755': Upper contact of lower reddish-brown mudstone unit is about 5 feet above the path.
6755-6770': Arkose scoured by channels. Reddish-brown mudstone dikes at north end probably was injected during burial (Figure 18B).
6775':
5': Massive yellowish-gray arkose.
5': Interbedded reddish-brown mudstone and tan arkose.
11': Reddish-brown mudstone.
Northward the top of the extensively burrowed lower unit is 8 feet above the path and is overlain by mottled arkose 11 feet thick which in turn is overlain by 4 feet of yellowish-gray arkose with large scale cross-bedding (Figure 19A).
6930': Slumped mudstone 3 feet above path.
6980-7015': Six inch layers of reddish-brown mudstone interbedded with reddish-brown silty sandstone a few inches thick with marked cross-bedding and scour and fill (Figure 19B).
7185': Well-developed cross-bedding in yellowish-gray arkose. Return to Park. LUNCH will be served at tables south of the parking area. Time here: 30 minutes.

Metamorphosed arkose and mudstone
Thermally metamorphosed yellowish-gray arkose and reddish-brown mudstone (as seen at STOP 3) in excavation on left.

Beginning of roadcut through Verdreitege Hook
Beginning of roadcut through Verdreitege Hook to inner side of the "sickle" (Figure 1).

Fault controlled gaps?
Gaps to east (right) and northeast (ahead) across Palisades may be controlled by faults (Thompson, 1959) or are former superposed stream valleys (Kummel, 1898, p.24).

Erratics on shore of Rockland Lake.

Gneiss and diabase erratics in till on right.
Some are more than 6 feet long.

Excavation in till.

Polygonal jointing
Unusually well-developed polygonal jointing in diabase at right, and in New York Trap Rock Quarry at Little Tor above road to left. North side of "sickle."

Talus slope up hill on left.

Arkose above tough reddish-brown mudstone on left,
Arkose above tough reddish-brown mudstone on left, on northern and outer side of the "sickle. "

Talus with very steep angle of repose.

Scarp has receded to the west.

North rim of High Tor
Road follows the north rim of High Tor and progressively crosses younger strata to the west.

Ramapo Mountains visible to the west.

Glacial erratics common.

Deposit of meltwater delta (?) on right
Deposit of meltwater delta (?) on right; in lowland between sill (left) and Ramapo Mountains (right).

Sand and Gravel quarry
Mt. Ivy Sand and Gravel Company quarry in Mt. Ivy meltwater delta dispersed to the south or southwest. About 5 feet of steeply dipping, light tan fore set beds above 8 to 10 feet of horizontal dark brown and reddish-brown to dark gray beds, and overlain by very poorly-sorted glacial (?) deposits.

Ramapo Mountains rise to west.

Outcrop of Ladentown diabase.
The Ladentown diabase extends for about 2 miles along the road, forming a series of low hills. It is crossed by several streams and is locally covered by glacial drift. The rock varies from fine-grained diabase to medium-grained vesicular basalt with intersertal texture, and structures like pahoehoe have been reported.
This igneous mass may connect with the Palisade diabase across the 2-mile drift-covered stretch to Mt. Ivy (Kummel, 1898, p. 41). The flow-like features of the Ladentown sheet and its position high in the stratigraphic sequence suggest that here the northwest end of the Palisade intrusion may have reached the surface.

Steep hill of diabase on left (east).

Closely-spaced, curved joints in diabase
Closely-spaced, curved joints in diabase on left differ markedly from the large-scale vertical jointing in the sill along the Hudson River.

East-dipping poorly-sorted conglomerate
East-dipping poorly-sorted conglomerate with clasts of Paleozoic rocks. In lower part some clasts are 1 to 2 feet in diameter.

Limestone conglomerate underlying hill.

Hill steepens on left. Ladentown diabase.

Hill of Ladentown diabase
Hill of Ladentown diabase and outcrop at road level on left (north). Fine-grained vesicular diabase with intersertal texture, but without flow texture in specimen examined. Interstices filled with very dark devitrified glass; scattered patches of iddingsite, amygdules of wordenite with a slender vein of quartz in some.

Abandoned quarries in limestone conglomerate
One of several abandoned quarries in limestone conglomerate on farm on southeast corner of intersection. Exposure of conglomerate on glaciated surface between old barn and house, just west of the private driveway.

STOP 4. Border Conglomerate in Upper Brunswick Formation.
Time here: 20 minutes.
This spectacular border conglomerate consists of rounded clasts as much as 4 feet in diameter in gravelly reddish-brown sandstone. Most of the clasts are gray cherty limestone, formerly quarried for burnt lime. Clasts of quartzite and sandstone are also present. The conglomerate is remarkably closely packed with little matrix. Conglomerate in this area east of the Ladentown diabase dips about 5° west (Klimmel, 1898, p. 40). See Figure 20 A, B.
This fanglomerate facies occurs at several places along the western boundary of the Triassic basin and is well-known as the "Potomac Marble" from Point of Rocks, Maryland.

Drive along the fault zone at the western border of the Triassic basin.
Ramapo Mountains to the west. The road parallels the Mahwah River which flows along the fault zone at the western border of the Triassic basin.

STOP 5. Border Conglomerate in uppermost Brunswick Formation.
Time here: 30 minutes.
The section exposed along the west side consists of about 10 feet of boulder conglomerate interbedded with, and overlain by reddish-brown gravelly sandstone. The clasts consist largely of a variety of Paleozoic limestones, together with red sandstone and Green Pond (Silurian) conglomerate and quartzite.
On the east side of US 202 the deposits are less coarse, and exhibit well-developed cross-bedding with dispersal direction to the south. The regional dip of the sequence is to the southeast, toward the Ladentown diabase (Figure 20 A, B).
A 12-foot limestone boulder has been reported just south of here.

Gneiss of Ramapo Mountains exposed on right

Exposure of slickensides in the Ramapo Fault zone.
Present relief between Precambrian crystalline rocks and Triassic sedimentary rocks is due to differential erosion. Top of hill on gneiss; quarry in diabase of Union Hill seen to the southeast.
At Union Hill, the trap is associated with dark purplish-red cobble conglomerate which contains clasts of quartzite, reddish-brown, greenish-gray and gray limestone, and amygduloidal basalt. The largest clasts present are as much as 1 foot in diameter and one 3 feet in diameter has been reported. About 30 percent of the clasts here are limestone.

Glacial erratics on right.

Glacial drift on right.

STOP 6. East end of Cherry Hill - NY 59. Brunswick Formation.
Time here: 30 minutes.
The Clarkstown Police will conduct our group across the highway to the best outcrops on the north side of the road.
This section in the lower part of the Brunswick Formation is about 0.2 miles long and consists of about 125 feet of strata (N30E, 6°W) composed of interbedded buff to reddish-brown feldspar-rich sandstone and reddish-brown mudstone. Many of the layers have well-developed crossbedding (Figure 21) commonly in the 1 to 2-foot sets; one cross-bedded unit is 11 feet thick. Dispersal direction generally is to the southeast, although some cross-beds dip westward (Figure 11). Unbedded mudstone and fine-grained sandstone apparently were mottled by burrowers.
The feldspar-rich sandstones here, as in much of the Stockton Formation, contain relatively abundant sodic plagioclase.
The traverse proceeds from east to west along the outcrop:
Top of Sequence (west end).
50'+: Reddish-brown mudstone, variably silty and fissile, with local sandy layers, On south side of road, at about this level, a 1-foot pebbly layer contains quartz clasts as much as 1/2 inch in diameter.
20': Reddish-brown sandstone interbedded with mudstone that is variably fissile. Base is marked by scour and fill, or flutes, and the basal bed contains intraformational mud chips. Lowest sandstone unit is conspicuously parallel-bedded, with convolutions overturned to the east. Local ripple-marks have crests trending N27°E. Scour and fill is common throughout the sequence.
Mudstone in the lower part of the unit contains a thin layer of drab mudstone with calcareous pellets. An ll-foot silty mudstone with thin layers of sandstone in the middle unit is conspicuously crossbedded.
15': Reddish-brown, cross-bedded mudstone, commonly weathers into slivers and chips. Drab calcareous nodules in upper part.
4': Reddish-brown sandstone with very thin mudstone interbeds, and a 3-inch layer of mudstone in the middle. Round mudstone clasts on some bedding planes; scattered quartz pebbles, locally in small lenses.
2.5': Reddish-brown fissile mudstone, with interbedded sandstone
10.5': Reddish-brown feldspathic sandstone. Commonly medium-grained with rare pebbles and locally cross-bedded.
5': Reddish-brown fissile mudstone.
East end of Outcrop.

STOP 7. Conglomerate in lower Brunswick Formation
Low ridge on lawn 157 Sickletown Road (Wright's property) consists of reddish-brown quartz pebble conglomerate and sandstone, locally crossbedded. Clasts are principally rounded quartz as much as 1 inch in diameter, a few pebbles are as much as 4 inches in diameter. This conglomerate, about 1/2 mile from STOP 6, emphasizes the lateral variation in Triassic deposits in Rockland County.

Outcrop of Palisade Sill on left.

Hill of cross-bedded calcareous arkose on right (west).
This sandstone with an interbedded 2-3 inch limestone unit (Kindle, 1944, p.4) overlies the Lockatong strata exposed in the Granton Quarry 1/2 mile to the south (see Figure 15A).

STOP 8. Lockatong Hornfels and subsidiary sill.
Enter driveway at south end of Diana Stores property. Drive to rear, turn right and drive to north end of property and south face of escarpment (see Colbert, 1966, Figures 1,2).
About 60 feet of Lockatong hornfels lies between the top of the Palisade Sill to the east and a subsidiary sill at Granton Quarry, North Bergen (Figures 15A, 16B, 22). The excellent exposure at the north end of the Diana Stores parking area consists of five complete hornfelsed "detrital" cycles (Van Houten, 1964), two of which are exposed along the east wall of the lower quarry. In contrast to the "chemical" cycles in the River Road excavation (STOP 1) each of these is thicker, shows extensive evidence of burrowing as well as shrinkage cracking, and contains cross-bedded siltstone and very fine-grained arkose pervaded by diopside in the upper part. The presence of prehnite and recrystallized feldspathized arkose in the middle and upper part of each cycle suggest metamorphism in presence of water vapor.
The overlying subsidiary sill, more than 20 feet thick, has been reported to contain an arkose xenolith a maximum of 10 feet thick and 100 feet long (Lewis, 1908, p. 135).
In spite of the extensive hornfelsing of the Lockatong rocks they still yield fossils of reptiles, fish, estheriids and plants (Colbert, 1965, 1966).

D: EXCURSION TO THE STERLING AND FRANKLIN AREA IN THE HIGHLANDS OF NEW JERSEY
By Eugene A. Alexandrov
Queens College of The City University of New York
GEOLOGY ALONG THE ROAD BETWEEN LONG ISLAND AND THE HIGHLANDS OF NEW JERSEY
The Geological trip to the Highlands of New Jersey starts at Queens College in Flushing and crosses the western part of Long Island in Queens County, the East River, Manhattan, the Hudson River, the Palisades, and the Lowlands of New Jersey.

D: EXCURSION TO THE STERLING AND FRANKLIN AREA IN THE HIGHLANDS OF NEW JERSEY

Crossing the Ronkonkomo terminal moraine.

Outwash Deposits
Grounds of the 1964-1965 New York World's Fair. Science Museum. The outwash deposits of Wisconsin age underlie the area between the terminal moraine and the East River.

Midtown Tunnel
Entrance to the Midtown Tunnel under the East River. The tunnel crosses ridges formed by Fordham Gneiss and Manhattan Schist, and depressions between the ridges eroded in Inwood Marble. The depressions are filled with Recent overburden.

Crossing Manhattan Schist
Crossing Manhattan along 34th St. , the underlying formations are mainly Manhattan Schist.

Entrance to Lincoln Tunnel
Entrance to Lincoln Tunnel under the Hudson River excavated in Recent sediments.

Western part of the tunnel crosses Upper Triassic continental seds
Boundary between the States of New York and New Jersey. The western part of the tunnel crosses the Upper Triassic continental sedimentary sequence underlying the diabase sill.

Crossing the escarpment of the diabase sill.

Fault in the diabase sill
Fault in the diabase sill (a narrow valley developed along this fault north of the road).

Leaving the diabase sill.
Leaving the diabase sill. The area is underlain by Upper Triassic shales, sandstones, and argillites. Turn northwest on Route 3 crossing the Hackensack Meadows.

Land rises because of harder sandstone
The land rises at the entrance to Rutherford because of the appearance of harder sandstones.

First Watchung Mountains formed by Triassic lava.

Lava with columnar jointing on the left side of the road.

Pillow lava structure on the left side of the road.

Triassic lava of the Second Watchung Mountains.

Triassic lava of Hook Mountain near Pine Brook. Third Watchung Mountains.

Escarpment formed by fault zone
Escarpment formed by the fault zone between the Precambrian Highlands and the Triassic basin (mantled by glacial till).

Entering Dover. Outcrops of Precambrian gneiss.

Crossing an inlier of Silurian rocks north of Dover.
Turning north on Route 15. Crossing an inlier of Silurian rocks north of Dover.

Visit to the mining property.
Sterling Hill Mine office of the New Jersey Zinc Co. Visit to the mining property.

Gerstmann's Private Museum of Franklin and Sterling Hill minerals, 14 Walsh Road, Franklin, N. J.

Oak Ridge Reservoir.
Northwestern border of graben in Precambrian gneiss -- inlier of Silurian and Devonian rocks. Southeast of Charlottesburg the rocks are Precambrian. The fault line separating the Highlands from the Triassic basin is crossed at Riverdale.

Triassic diabase sill.

E: TACONIAN ISLANDS AND THE SHORES OF APPALACHIA
By Robert M. Finks, Queens College of the City University of New York
Within the Precambrian Highlands of northern New Jersey and adjacent New York are several infolded and infaulted belts of Paleozoic sediments. The easternmost of these belts, the Green Pond - Schunemunk outlier; preserves Silurian and Devonian rocks as well as Cambrian and Ordovician. The mid-Paleozoic sediments lie some 25 miles farther southeast than the main outcrop belt of the miogeosyncline, and represent a sampling of material deposited approximately that much nearer the source. They provide a record of those tectonic events and geographic conditions in the source area whose influence did not spread far enough to become manifest farther west.

E: TACONIAN ISLANDS AND THE SHORES OF APPALACHIA

Start of a spectacular new cut in the Palisades Diabase.

End of new cut
End of new cut, now overlying baked shales of the Newark Series may be seen, parallel to the top of the sill.

Meanders of the Hackensack River on its flood plain.

Road follows Passaic River flowing south.

Cut in First Watchung Basalt
Cut in First Watchung Basalt, an extrusive lava. Note curvicolumnar jointing.

Fanned columnar jointing
Fanned columnar jointing followed on LEFT by pillow-lava.

Passaic River flowing north in subsequent valley
Passaic River flowing north in subsequent valley between First and Second Watchung ridges. This is upstream from where we last saw it. It crosses First Watchung Ridge at Paterson Falls.

Second Watchung Basalt.

Third Watchung (Hook Mountain) Basalt.

Wisconsin terminal moraine.

Third Watchung (Hook Mountain) Basalt again.
Third Watchung (Hook Mountain) Basalt again. This has been bent around as part of a syncline in the Newark Series.

STOP 1. Pompton Lakes. Triassic Border conglomerate.
Turn left into Moyias Road and park. Walk across road (CARE!) and north along grass (STAY OFF PAVEMENT!) to outcrop.
(Wanaque, N.J., 7 1/2 - minute Quadrangle.)
This outcrop provides a sampling of the exposed bedrock that lay immediately to the west of here during late Triassic time. Coarse conglomerates such as this are confined to the immediate vicinity of the Triassic border fault and were apparently deposited as alluvial fans at the base of the fault scarp by east-flowing streams. No Precambrian pebbles can be recognized in this outcrop and presumably the Precambrian, now exposed in the hills immediately to the west, still lay covered beneath Paleozoic sediments. Large rounded cobbles, some more than a foot across, of a conglomerate of white quartz pebbles in a red quartzite matrix, closely resemble existing outcrops of the Silurian Green Pond Formation or the Devonian Skunnemunk Formation, both exposed in the outlier some ten miles west of here. Of more interest for the reconstruction of the paleogeography of the pre-Silurian uplift, is the abundance of white-weathering dolomite cobbles that could only have come from the Cambro-Ordovician carbonate sequence. These cobbles are sometimes less well rounded than the quartzite cobbles and must have been transported for no very great distance. The base of the Silurian rests directly on the Precambrian ten miles to the west. The CambroOrdovician carbonates were probably exposed somewhere between there and here in Triassic times and therefore could not have been removed during the pre-Silurian uplift. We will see at STOP 2 that the Trentonian phyllites are still preserved in this vicinity. These data place the eastern border of the pre-Silurian uplifted and eroded area as somewhere between here and STOP 3, only ten miles to the northwest.

STOP 2. Riverdale - Pomton. Annsville Phyllite.
(Pompton Plains, N. J., 7 1/2 - minute Quadrangle. )
After looking at the outcrop we will take a short REST STOP in the Riverdale Diner.
Walk east a little more than a block on the south side of the Hamburg Turnpike, crossing the bridge over the Wanaque River, and descend to the south side of the east abutment of the bridge. Here is exposed a small, but apparently genuine, outcrop of black phyllite; the outcrop is submerged at high water.
This outcrop was mapped as Hudson Schist in the USGS Passaic Folio (Darton, et al. , 1908) a name applied to the rocks now called Manhattan Schist, as well as to the metamorphosed pelites of the upper Hudson Valley now referred to the Normanskill - Snake Hill sequence (Ordovician, Trentonian). I see no reason to question these correlations. This outcrop is called Annsville here because it occurs in the same structural position as the type Annsville at Peekskill, 30 miles to the northeast along the Triassic border fault, and because it resembles the type Annsville lithologically. It also resembles lithologically ( and structurally: refolded foliation) the phyllitic phase of the Mount Merino Formation in Balk's classic area in Dutchess County, as at Noxon near Lagrangeville. Near Clinton, New Jersey, 40 miles to the southwest along the border fault, a sizable patch of the Cambro-Ordovician sequence is exposed between the Triassic and the Precambrian. The Ordovician pelites in it were mapped as Martinsburg Shale (Bayley et al., 1914).
The present outcrop was interpreted in the Passaic Folio as a fault sliver, or "horse, " along the Triassic border fault. It is also possible that the pre-Triassic basement is generally much closer to the present surface along the border fault than usually reconstructed, and that much of the Triassic subsidence was taken up by faulting or warping farther east beneath the basin. The Cambro-Ordovician area near Clinton was mapped in the USGS Raritan Folio (Bayley et al., 1914) as lying uncomformably beneath the Triassic, and the present outcrop may have the same relationship.

Glacial lake delta on left. We have crossed Triassic border fault.

Outcrops of Precambrian gneiss.

Cut in Wisconsin till on left.

STOP 3. Newfoundland: South end of Kanouse Mountain.
Green Pond Formation. (Newfoundland, N. J., 7 1/2 minute Quadrangle. )
Walk north across old highway to nearest outcrop on north side of road. These are the lower conglomerate beds of the Silurian Green Pond Formation dipping steeply northwest. The conglomerate occurs in rhythmically repeated, upwardly-fining, 2 or 3 foot, cross-bedded units. Most of the pebbles are rounded milky-quartz, but red chert, dark shale, and other rock types occur.
Walk uphill, northeastward into the woods, paralleling the base of the cliffs but keeping about 50 feet east of them. About 100 feet or so into the woods large talus blocks of the lowermost beds are passed. They are more coarsely conglomeratic, and contain many angular or subangular pebbles, a few inches across, of green chert, red chert, quartz hematite phyllonite, quartzite, dark shale or slate, along with milky-quartz.
Another hundred feet or so further will bring you to the first outcrops of Precambrian Gneiss. An interval of 25 feet or so, covered with large talus blocks of Green Pond separates the nearest Precambrian outcrops from the exposures of Green Pond in the base of the cliffs. The contact is not exposed.
Return, following the base of the cliff as closely as talus and underbrush permit. At a point opposite the first ledges seen near the road, climb up to a broad rock surface on top of these ledges to observe spectacular Liesegang rings of hematite developed in the finer-grained layers of the rhythmic sequences. (WATCH YOUR STEP.)
Return to the road, cross the old highway and continue west across the grass plot to the main highway. Walk west along the shoulder (STAY OFF HIGHWAY! WATCH TRAFFIC!) to a cut in the Upper Quartzite Member of the Green Pond. The cut shows a small anticline and syncline parasitic upon the main synclinal structure (drag folds). A prominent thin pebble bed makes a convenient stratigraphic marker. Note well-developed quartz-filled gash-fractures along minor shear zones. At the westernmost end of the cut the lowermost red arkose beds of the Lower Arkose Member of the Longwood Formation are exposed in contact with the top of the Green Pond. These beds will be seen in the same stratigraphic position at Highland Mills (STOP 6-A).
(Note: A complete section between the basal beds and the Upper Quartzite Member is exposed in the woods along the south end of Kanouse Mountain, but we will not take the time to visit it. The Middle Arkose Member seen at the north end of the outlier (STOP 5) does not seem to be present here. )

Oak Ridge Reservoir.
Crossing high-angle fault between outlier and precambrian forming west boundary of outlier. Fault-line scarp visible to left along west shore of reservoir.

Flood plain of Pequannock River.

Entering small outlier of Cambro-Ordovician.

Outcrop on right of Cambro-Ordovician carbonate.

Dump of old Buckwheat zinc mine on right.
Franklin minerals may be collected here (fee). Outcrops of Precambrian Franklin Marble.

STOP 4. Hardyston - Precambrian Unconformity and Stissing Dolomite.
(Franklin, N.J., 7 1/2 - minute Quadrangle.)
Walk east from Wildcat Road toward golf course just south of point where wooded ridge intersects road obliquely. Walk northeast along east base of ridge facing golf course about 25 feet to first outcrops. Here Lower Cambrian Hardyston Formation rests on light colored Precambrian gneiss. The Hardyston dips 550 NW. The basal five feet or so of the Hardyston contains pebbles of quartz and fresh feldspar up to an inch in diameter. About 20% of the pebbles are feldspar. PLEASE DO NOT HAMMER ON THIS OUTCROP. Exposures of the Cambrian - Precambrian unconformity are rare and should be preserved as an exhibit for students.
The type locality for the Hardyston is 2 miles to the northeast at Hardystonville along this same continuous outcrop belt. The Hardyston here is in one-foot beds that are internally cross-bedded in smaller units. The five feet or so of conglomerate grades upward into dark-gray, flaggy, quartz-sandy dolomite that underlies most of the ridge and totals about 100 feet in thickness. The dark-gray dolomite may represent the Lower Cambrian Stissing Dolomite.
Climb over the ridge across strike to Wildcat Road and walk north along the road past a covered swale to the next outcrops. These may be the base of the Upper Cambrian Pine Plains Formation. The light-weathering dolomite is interbedded with thin, ripple-marked beds of quartz-sandstone. Oscillation and interference ripples are beautifully displayed both on bedding surfaces and in cross-section. An extensive section of higher carbonate beds is exposed along the road for several hundred feet.
The base of the Hardyston represents a shore, but not a shore of Appalachia. The Early Cambrian sea transgressed westward onto the craton. The importance of this outcrop is to show that the Precambrian which was exposed at the surface at Newfoundland, during the Silurian, is still covered by the Cambrian at Franklin, only 10 miles to the west.

STOP 5. Gould Quarry. Unconformity of Silurian on Cambrian.
Although here called STOP 5, because of the addendum, it was originally called STOP 4A.
(If time permits.)
(Newfoundland, N.J., 7 1/2 minute Quadrangle.)
Walk west into woods following old dirt road to abandoned . and overgrown Gould limestone quarry. The first exposures are of Precambrian gneiss. A few feet of covered interval are succeeded by ledges of Hardyston Sandstone outcropping on the east side of a low ridge. The Hardyston dips steeply northwest and grades upward from a few feet of pebbly quartzite to a quartz-sandy dolomite, that forms the top of the ridge. Walcott (1893) found Olenellus in this dolomite a mile or so to the north, and it is presumably the equivalent of the Lower Cambrian Stissing Dolomite of New York. Just over the crest of this ridge, on its western slope, and about 60 feet stratigraphically above the Hardyston quartzite, the dolomite is succeeded abruptly by a coarse quartz-pebble conglomerate that rests on the irregular upper surface of the dolomite and includes clasts of dolomite just above the contact. This coarse conglomerate appears to be the base of the Green Pond Formation, for it is exposed intermittently from this point westward, across a narrow valley to the main mass of the. formation in Kanouse Mountain. The upper surface of the dolomite, on which the Green Pond rests, is a karstic surface, for pockets of the same conglomerate appear in the basal part of the dolomite, on the east side of the ridge toward the south end of the old quarry, not far above the Hardyston Quartzite. Kfunmel and Weller (1902" pp 7) were apparently the first to interpret these pockets as solution cavities filled from above. The pockets are lined with a thin layer of shaly sediment between the dolomite and the conglomerate. These solution fissures extended some 30 feet below the pre-Silurian surface.
This locality is about three miles north of STOP 3 where the Green Pond rested directly on the Precambrian. The Cambrian first appears beneath the Silurian a half-mile south of here at the north end of Echo Lake. The obvious unconformity here, barely 70 feet above the base of the Cambrian, is the strongest evidence for the unconformable nature of the less well exposed Silurian-Precambrian contact to the south~ We are here on the northerly flank of the pre-Silurian uplift.
Dr. Barnett has discovered Ordovician shales on the west side of the outlier northwest of Bowling Green Mountain. Inasmuch as the Silurian rests directly on the Precambrian at Bowling Green Mountain, the northern limit of the exposed Precambrian lay just north of there. A line connecting that point with the corresponding contact at the north end of Echo Lake should be parallel to the axis of the pre-Silurian uplift. It has an ENE-WSW trend that is at variance with the axis of the outlier, though one that corresponds with late folds in the New York City group in Westchester County (see Trips A and H as well as Fisher et al., 1961.) This m~ be a late Taconian fold direction. I~ also parallel with the Cambrian-PreCambrian contact on either side of the outlier south of Monroe (see Figures 1 and 2.) Unfortunately the Silurian is faulted out of the outlier at that point so that the trend cannot be demonstrated to be pre-Silurian there.

Outcrop of Cornwall (Pequannock) Shale (Middle Devonian).
Outcrop of Cornwall (Pequannock) Shale (Middle Devonian). The road follows the strike of the Upper Silurian-Lower Devonian. On the right is the ridge of Green Pond Conglomerate, on the left the ridge of Bellvale Sandstone.
This comment was on the original trip before the new stop was added. Hence the route no longer comes this way...

Greenwood Lake
To the right is Greenwood Lake. Beyond it to the east are hills of Precambrian forming the east boundary of the outlier. The Green Pond has been faulted out. To the left are nearly continuous outcrops of the lower beds of the Bellvale Sandstone (or the upper part of the Cornwall shale). The ridge to the left (west) is Bellvale Mountain, the type locality of the Bellvale Sandstone.

Woodbury Falls
Woodbury Falls, where railroad trestle crosses road. Marine beds of Bellvale sandstone in bed of Woodbury Creek on right, non-marine beds on left (west) side of road.

Precambrian hill on left (north) and Siluro-Devonian hill on right.

STOP 6. North end of Pine Hill. Green Pond Formation.
Although here called STOP 6, because of the addendum, it was originally called STOP 5.
(Popolopen Lake, N. Y., 7 1/2 - minute Quadrangle.)
Outcrops near the road, at turn-off of private dirt road, are of Lower Conglomerate Member, dipping steeply northwest. The pebbles are almost entirely milky-quartz.
Walk into the woods across strike. About 100 feet NNW are outcrops of the Middle Arkose Member. Fresh, angular, cleavage fragments of feldspar, up to 1/2 inch across, are common along with quartz pebbles in a fine reddish matrix. This unit can be recognized 2 1/2 miles to the southwest along strike near Highland Mills (Figure 4 and Table 1).
Continue 200 feet or so further northwest to the base of ledges that expose the Upper Quartzite Member. (Some care should be exercised to avoid Copperheads in climbing over these ledges.)
Beyond this the Longwood is poorly exposed on the top of the ridge. We will see a better section at the next stop.
Return to the road.

STOP 7. South end of Pine Hill.
Although here called STOP 7, because of the addendum, it was originally called STOP 6.
Green Pond - Longwood - Decker Ferry. (Popolopen Lake, N. Y., 7 1/2 - minute Quadrangle.)
Walk north along Skyline Drive from intersection with Pine Hill Road. The first outcrops on the right (east) side of road are of the Upper Quartzite Member of the Green Pond, with characteristic Liesegang rings of hematite, and quartz-filled fractures.
Farther on the Lower Arkose Member of the Longwood is exposed in poor outcrops. If time permits, climb the hill to the well-exposed ledges on top of the ridge. The lower part of the measured section (Figure 4 and Table 1) was made here, from the Lower Arkose Member of the Longwood down to the Middle Arkose Member of the Green Pond; the section in the Green Pond was measured with several jogs northeastward along strike to preserve continuity of section. The intergrading contact of the Green Pond and Longwood is well exposed here. Do not go further up-section (northwest) than the lower beds of the Lower Arkose Member of the Longwood: the ground slopes downward to the unprotected edge of a sheer 100-foot cliff that drops vertically into the shale quarry to the northwest. STAY AWAY FROM THE EDGE OF THE CLIFF!
Continue north on Skyline Drive to the entrance to the shale quarry and turn right into the quarry. steeply northwest-dipping bedding planes of the Upper Shale Member of the Longwood form the southeast wall of the quarry, higher beds being exposed stepwise toward the north. A zone of contorted bedding is exposed just above the first large bedding plane. Mud-cracks and curious spheroidal pits one to six inches in diameter, are common on some of the higher bedding planes.
The remainder of the section was measured at the northeast end of the quarry, where the Decker Ferry Formation is exposed, separated from the highest beds of the Longwood by a 40-foot interval covered with red shale debris. Some of the Decker Ferry is covered by a few inches of soil, but can be exposed by digging with the hammer. The beds seem to be in place and were measured inch-by-inch with a tape. Most of the formation consists of interbedded quartz-sandstone and dolomite. Quartz-sandstone predominates in the lower beds and this part is here called informally the "Binnewater" Member because it is homotaxial with the type Binnewater of the High Falls area, 40 miles to the north. A prominent outcrop (Unit R) of this lower part of the Decker Ferry is exposed half-way up the slope at the northeast end of the quarry, to the right of a grassy embankment.
Higher in the section thinly laminated (stromatolitic?) mud-cracked, somewhat argillaceous dolomites predominate, with minor quartz sandstone interbeds. Intraclasts are common. This part of the formation is designated informally as the "Waterlime" Member. It resembles lithologically the waterlimes of the Rondout Valley which lie above the Binnewater Sandstone at its type locality. Outcrops may be seen lower on the slope and towards the northwest.
The continuous alternation of the two rock types, sandstone and dolomite, with mud-cracks in the dolomite often being filled with quartz-sandstone, suggests that the two types of sediment were being deposited contemporaneously in adjacent, spatially shifting areas, perhaps sandy beach and tidal mud-flat. (Southard, 1960, mapped the "Binnewater" and "Waterlime" units together as his sandy-claystone unit, emphasizing their continuity. )
The highest beds of the Decker Ferry are lithologically quite distinct, though sandstone & dolomite interbeds indicate their relationship to the underlying units. This unit is separated as the Skyline Calcarenite Member of the Decker Ferry Formation (new name). It includes all the calcarenite beds exposed in the quarry, its type section (see measured section, Table I). Minor interbeds of sandstone and dolomite are present. The principal lithology is a red to blue-gray coarse crinoidal clastic limestone, full of whole shells (see faunal list), cross-bedded, and heavily charged with hematite, which frequently partially replaces some of the fossils. The fauna has not been completely studied but the following have been tentatively recognized:
Bryozoa:
Ptilodictya sp. cf. P. frondosa Weller
massive trepostome, cf. Monotrypa corrugata Weller
Brachiopoda:
Atrypa "reticularis"
rhynchonellid, cf. Camarotoechia sp.
Coelenterata:
Favosites sp.
horn coral
Arthropoda:
ostracode, cf. Dilbolbina sp.
Echinodermata:
pelmatozoan (Probably crinoid) columnals
This fauna is hardly diagnostic of age, but is consistent with the Decker Ferry of New Jersey (Weller, 1903). Neither the fauna nor the lithology are anything like either the Wilbur Limestone or the Glasco Limestone, which fall into this part of the section in the Rondout Valley. Neither is it like any of the higher limestones of the Helderberg Group. The Becraft is the closest lithologically, and probably environmentally, but the fauna is certainly not the same. This appears to represent a shallow-water shell-bank environment. The name of the member is derived from the nearby Skyline Road.
Thicknesses of the members recorded in this section are as follows:
| Feet | Inches
Decker Ferry Formation | |
Sky line Member | 7 | 8
"Waterlime" Member | 28 | 9
"Binnewater" Member | 22 plus |
Longwood Formation | |
Upper Shale Member | 88 | 2
Lower Arkose Member | 80 |
Green Pond Formation | |
Upper Quartzite Member | 222 | 10
Middle Arkose Member | 82 plus |
Walk back out of the quarry, south on Skyline Road and west on Pine Hill Road. At the bridge over the Thruway one can see the Lower Arkose Member of the Longwood exposed north of the east abutment. On the west side of the Thruway, the first visible outcrop is that of the Connelly Conglomerate. When the writer first visited this cut in 1954, just after it had been partly blasted through, a white-to-violet-mottled, friable, clayey, fine sandstone, with characteristic thin inter laminae of dark-gray shale crumpled to give the rock a "zebra-stripe" appearance, was exposed to, the south of the Connelly. It has since been grassed over. Boucot (1959) named this unit the Central Valley Sandstone, and this is its type locality. North of the Connelly, on both sides of the Thruway, is a nearly complete section of the Onesquethawan Series. Access to the Thruway cut is prohibited and the prohibition strictly enforced by State Police.
Continue west on Pine Hill Road to the first black-top road on the right and walk up this road to its dead end.
STOP 6-B. Connelly Conglomerate.
Low ledges on the east side of the road expose the rather well-sorted quartz-pebble conglomerate (2 to 6 mm clasts) of the Connelly. Oriskany fossils establish its age. It is equivalent to an argillaceous limestone 25 miles to the west and to a similar conglomerate followed by an argillaceous limestone 40 miles to the north. This represents a shoreline facies, a pebbly beach on the temporarily stable shore of Appalachia. Most of the fines have been winnowed out.
It may be possible to find Central Valley float on the ground to the south.
Walk back to Pine Hill Road and turn right. At the bend in the road is a stone fence made of Connelly boulders, resting on small outcrops of the Connelly. Where road bends sharply to the left, turn right on private road, then take short path down to railroad tracks opposite abandoned station. Turn right and walk to first outcrops on east side of tracks.
STOP 6-C. Highland Mills. Highland Mills Sandstone and "Middle Member" of the Esopus Formation. (Popolopen Lake 7 1/2 - minute Quadrangle. )
WATCH OUT AND LISTEN FOR TRAINS. DO NOT SIT ON TRACK OR PLACE OBJECTS ON TRACK. TRAINS COME THROUGH FAST AND WITHOUT WARNING. If a train comes stand well back; there is plenty of room on either side of the track.
This stop demonstrates near-shore and off-shore deposits under conditions of strong influx of terrigenous clastics. The series of beds at the south end of the cut are of the upper part of the Highland Mills Sandstone of Boucot (1959). These light-blue-gray, light-brown-weathering, subgraywackes are dominated by evidences of shallow-water deposition. A prominent set of bedding planes display oscillation ripples of various sizes. The ripples tend to be uniformly oriented, roughly NNW - SSE when rotated back to horizontal. (The beds here strike N 500 E and dip 600 NW.) Just north of the ripple-marked layers are lenses of closely packed, jumbled, disarticulated shells. The lenses pinch out within a few feet, from thicknesses of a foot or so. (Preservation on the weathered surfaces is in the form of molds; the most common fossil is Leptocoelia flabellites, but besides the many other brachiopods described by Boucot (1959) there occur gastropods, pelecypods, horn corals, trilobites and other fossils.) Associated with the shell-lenses are shaly beds packed with the ichnofossil Phycodes. All these features are characteristic of the Cruziana-facies of Seilacher (1964) representing shallow-water above wave-base, littoral or sub-littoral.
The "Middle Member" on the other hand, exposed farther north along the tracks, represents Seilacher's deeper-water, sublittoral to bathyal Zoophycos-facies. Bedding planes are covered with the ichnofossil Zoophycos (= Taonurus, = Spirophyton). The rock is massive-bedded and the bedding planes very even. (The rock weathers brown to orange, the fresh rock is almost black.) Although described in the literature as a mudstone, most beds are poorly-sorted graywacke sandstone with about 55% to 85% quartz-grains of fine-sand size, and the rest chiefly finegrained matrix (data from Miss Janice Lumnitz and Mr. Maury Morgenstein). Fossils are sparsely scattered on the bedding surfaces, mainly the brachiopods Leptocoelia flabellites and Spirifer macra. On many bedding-planes concave-up valves outnumber concave-down valves (from Miss Janice Lumnitz) suggesting settling-out through water followed by rapid burial without further reworking. The unsorted nature of the sediment also points to rapid sedimentation and the sparseness of fossils suggests dilution by rapid influx of terrigenous material.
Feldspar may be less abundant here than in the underlying Highland Mills Member, but the whole Esopus sequence is strongly suggestive of a pulse of erosion of the source area (Appalachia).
The Esopus sequence starts with deep-water Zoophycos-bearing beds (the Mountainville Member of Southard, 1960). The upper part of the Highland Mills Member (restricted Highland Mills Member of Southard) is mostly shallow-water. The "Middle Member" is· again mostly deeper water. The Woodbury Creek Sandstone appears to be mostly shallower water again. It is more fossiliferous than the "Middle Member" (dominated by the pelecypod Cypricardinia and the brachiopod Schuchertella). The fossils are evenly spread on the bedding planes, rather than in lenses as in the Highland Mills Member, and ripple marks are not well-developed. Also Zoophycos has been observed on some beds. It would thus seem to be of a depth intermediate between that of the Highland Mills Member and that of the "Middle Member".
The succeeding Kanouse Sandstone, a clean, somewhat pebbly, orthoquartzite, again marks a stable shoreline deposit, with a falling off of terrigenous influx permitting better sorting of the material. It appears to be the shoreward equivalent of limy deposits to the north and west (Schoharie and/or Onondaga).

STOP 8. Monroe. Bellvale Formation.
Although here called STOP 8, because of the addendum, it was originally called STOP 7.
(Monroe, N. Y., 7 1/2 - minute Quadrangle.)
Between here and the Monroe-Washingtonville exit are exposed about 2000 feet of the Bellvale Formation, essentially a complete section. Details of the section are given in the measured section, Table II and Figure 5.
The lowest beds at the east end of the outcrop are shaly siltstones that are close to the base of the Bellvale, if indeed they are not to be considered the highest beds of the underlying Cornwall Shale. The beds immediately above are graywackes that carry Mucrospirifer and Spinocyrtia, thereby demonstrating their Hamilton age and marine nature. A small Chonetes is also common. This entire lower part of the section here is identical, lithologically and faunally, to the section exposed in the bed of Woodbury Creek, at Woodbury Falls, north of Highland Mills, where the railroad trestle crosses Route 32.
As one goes up-section, intercalated beds of uncleaved sandstone increase in thickness and ultimately dominate the section by the time one reaches the abutment of the overpass. Up to here the beds are evenly laminated without any indication of large scale cross-bedding or channeling.
Just at the east side of the overpass is a zone of ball and pillow structures and load-casts. These structures are widely recognized in the Catskill Delta rocks as marking the transition-zone from marine to non-marine beds. The beds beneath the overpass are still marine, however, as brachiopods have been found in them. Nevertheless, the nature of the bedding changes from the preceding even lamination, to evidence of channeling, cut-and-fill structure, and cross-bedding. The rock becomes lighter and coarser, a subgraywacke. Load-casts are present intermittently, and at least one zone of pebbles scattered in subgraywacke is present. It would appear that we have passed from the evenly laminated prodelta and foreset beds to channeled 3l1d irregular top set beds.
West of the overpass the subgraywacke becomes still coarser and lighter. Thin interbeds of shale become more common and numerous shale chips appear in the sandstones. Many of the smaller grains appear to be shale clasts or perhaps phyllite. Obscure plant remains and possible wood-fragments appear. No marine fossils have been found, and these deposits may have been made on the subaerial part of the delta.
Beyond the culvert the rock becomes even coarser and more lithic. Here unmistakable plant fragments are present including pieces of branches of scale-trees or related lycopsids a half-inch or so in diameter and clearly shoWing the leaf scars and internal woody fibers. (The first such were found by Mr. Harvey Zeiss; I have since found others.) Note the well-developed glacial striae and chatter-marks on some of the outcrop surfaces.
Beyond this point is a long succession of massively cross-bedded subgraywacke sandstones with shale interbeds. There are also four prominent units of highly cleaved mudstone, decreasing in thickness from 31 feet for the first such unit, to 11 feet for the last. These are probably flood -plain muds. The last of these units is clearly channeled and filled by the succeeding sand , probably a stream-channel deposit.
The Bellvale section ends with coarse pebble beds at the center of the syncline, just at the Monroe-Washingtonville exit. These beds have the character of the overlying Skunnemunk Formation, except that they lack the red color characteristic of that formation. The pebbles include besides milky-quartz, rocks such as chert, quartzite and shale or slate, not too unlike the pebbles included in the base of the Green Pond at STOP 3. We are probably dealing here with Piedmont alluvial deposits.

Return to the hotel
Return to the hotel via Route 17, New York State Thruway, Major Deegan Expressway, etc.

F: THE PLEISTOCENE GEOLOGY OF THE MONTAUK PENINSULA
By Walter S. Newman, David L. Thurber, David H. Krinsley,
Queens College of the City University of New York;
and Leslie A. Sirkin, Adelphi University.
Long Island is a long narrow island reaching east-northeastward from New York City to form a "fish-like" extension of New York State. The island lies south of and is approximately parallel to the Connecticut shore of New England and is separated from it by Long Island Sound. Long Island forms the north shore of an Atlantic Ocean reentrant known as the "New York Bight". Although part of the Coastal Plain Physiographic Province, Long Island features a topography almost completely modified by glacial and proglacial processes. Two conspicuous end moraines extend from west to east along the axis of the island. The older Ronkonkoma moraine, probably Wisconsin in age, makes up a major portion of the Montauk Peninsula. The younger Harbor Hill moraine generally follows close to the north shore of Long Island east to Orient Point. The island abounds in other glacial and proglacial features such as the coalescing outwash fans and aprons which form much of the southern portion of the island.

F: THE PLEISTOCENE GEOLOGY OF THE MONTAUK PENINSULA

Flushing Meadow
Flushing Meadow-the site of the two New York World's Fairs. The geology of this swale has been described by Newman (1966).

Queens College
To your right (south) the campus of Queens College of the City University of New York.

Alley Creek Valley
A drowned and then partially filled embayment of Long Island Sound.

Lake Success on your right
The lake has an area of 60 acres, a maximum depth of 72 feet, no surface outlet, and is one of the larger kettles on Long Island. Note the (both) Ronkonkoma and Harbor Hill morainal topography.

Descend from Ronkonkoma moraine
Plainview(!)-Here we descend for a short distance from the Ronkonkoma moraine onto the outwash plain. Note the relief contrast.

Descend to the Huntington Plain
After crossing West Hills, one of several central Long Island areas where pre-Pleistocene strata rise considerably above sea level and approach the surface, we descend to the Huntington Plain which may be the site of a proglacial lake overlain by a thin veneer of outwash (Lubke, 1964).

Half Hollow and Dix Hills
We rise again into the Half Hollow and Dix Hills, areas similar in structure to West Hills. The Ronkonkoma End Moraine lies on the north flanks of these hills.

Outwash plain then Ronkonkoma moraine
Sunken Meadow-Sagtikos State Parkways. Here we descend once again for a short time onto the outwash plain. Pilgrim State Hospital forms the large building complex on the right (south). We then once again mount the Ronkonkoma moraine.

Descend from Ronkonkoma Moraine to outwash plain
We descend almost immediately from the Ronkonkoma Moraine onto the outwash plain. Note the distinctive "pine barrens" vegetation of scrub-oak and pine. This area is underlain by a podzol soil having a bleached lower "A" horizon. This area of Long Island is devoid of agricultural potential because the outwash lacks the loess cover which is conspicuous in farming areas on outwash further east.

Continue east through "pine barrens" on outwash plain.

Eastport: temporary terminus of Sunrise Highway.
Northeast on Route 51. Note farming activity on outwash plain. The surficial loess makes the difference! Route 51 climbs onto the Ronkonkoma moraine and then descends towards Riverhead and the pitted outwash plain between the Ronkonkoma and Harbor Hill End Moraines.

Riverhead: at the Peconic River mouth.

Reeves Bay on left (north).

Cross Shinnecock Canal. We mount the Ronkonkoma Moraine once again.

Bluff Road
Bluff Road marks the crest of an abandoned wave-cut marine cliff cut into Ronkonkoma outwash. Progradation due to the construction of the Napeague Tombolo has separated the bluff from the sea for distances of up to 1.5 miles.

Descend from bluff
We descend from the bluff, now on our left onto the Napeague beach-and-dune-complex Tombolo.

Abandoned wave-cut bluff on left
Note the abandoned wave-cut bluff on left as well as the dunes on glacial drift. Drive half-left onto the New Montauk Highway mounting the Ronkonkoma Moraine at Hither Hills.

The village of Montauk built, for the most part, on a double tombolo.

STOP 1. Montauk Point State Park, Montauk Point.
45 minutes. REST ROOMS ARE IMMEDIATELY ADJACENT TO THE PARKING LOT ENTRANCE. Montauk Lighthouse was built in the years 1795-1797 about 300 feet from mean high water. It is now only about 60 feet from the water's edge. Following the field trip leaders, walk southeast crossing the road (WATCH OUT FOR TRAFFIC!) and follow the trail which commences at the lighthouse reservation entrance and skirts the south boundary down to the water's edge. To your left, towards the lighthouse is the section sketched by Fuller (1914, fig. 159, p. 144) which probably includes the type Montauk Till section. Starting from the base, Fuller identified the units in the bluff as "(a) Till phase of Montauk till member; (b) boulder pocket; (c) sand and clay phase of Montauk member; (d) clayey sand phase of Hempstead gravel member; (e) normal sandy phase of Hempstead gravel member". We interpret this section as consisting of Ronkonkoma (=Montauk) Till; a lag concentrate; laminated, probably lacustrine, silt, sand and clay; grading upwards into eolian silt and sand. Over towards the northeast, the section includes some stratified drift. The laminated unit appears to occupy a swale (kettle?) in the till. Listen (sic!) to the geomorphology and sedimentology. Returning to the busses, climb the bluff and look southwest. The bluffs are usually fringed by steep shingle-beaches and extend four miles southwestward to Ditch Plains.

Montauk Air Force Station.
Stop! We are now under military jurisdiction and supervision. Proceed under Air Force direction to south shore.

STOP 2. South Shore Beach
1 hour. Leave the buses and enter upon the south shore beach. Immediately to the west is a mass of laminated silt and fine sand which Fuller considered "possibly" Gardiners. We believe this unit represents a proglacial lacustrine deposit. Walk southwest for 0.5 mile. Here we find the exciting section described by Perlmutter and DeLuca (1963). The major unit is the Montauk Till forming a 0.5 mile long open anticline. The Montauk Till overlies stratified drift consisting of interbedded gray and brown clay, laminated green and gray silt and clay, and some thin lenses of fine brown sand. Perlmutter and DeLuca found neither forams nor diatoms in the lower stratified drift which represents the oldest unit we will view on this trip. Immediately above the Montauk Till is stratified drift which ranges in thickness from a featheredge to about 30 feet and is composed chiefly of beds and lenses of brown and gray silt, fine to medium sand, and clayey sand. We interpret this unit as likely to be proglacial lacustrine in origin. Perlmutter and DeLuca report 5 to 20-foot-thick till unit on top of the upper stratified drift. However, Newman fails to note it. Occasional pockets of loess cap the section.

Note the morainal topography and surface erratics on right.

STOP 3. Montauk Airport Archeological Site.
30 minutes.
Geologically, this site includes a medley of till and ice-contact deposits including lenses of red-brown clay, silt and fine sand which Fuller would have referred to as Gardiners Clay. Overlying the drift is a lag concentrate, including occasional ventifacts, while the entire section is capped by loess. Pelecypod valves, including Crassostrea virginica, Venus mercenaria and Pecten irradians, form a "shell midden" associated with the upper portion of the loess blanket. The absence of artifacts suggests the midden dates from the "Archaic Stage" of aboriginal development and is thus some 4000 to 6000 years old. These aborigines probably harvested the lagoon or bay that existed immediately to the north of the site which has since been filled by the tidal marsh sere and then covered with sand dunes.
LUNCH STOP! Perhaps. It depends upon the wind direction. If conditions are unfavorable here, we'll eat at STOP 4.

STOP 4. Ditch Plains Stratigraphic Section.
45 minutes.
Enter upon the beach and walk west 0.2 mile. At this point, the bluff presents a rather simple section consisting of the Montauk Till, a lag concentrate, with loess on top. However, further to the east, additional units are found beneath the loess. These new units of stratified drift appear to have an easterly dip component. At the east edge of the bluff, accentuated by a morphological reentrant at the back of the beach, the stratified drift clearly takes on the aspect of a delta built into a standing body of water. However, this critical exposure is frequently obscured by slump from the still younger unit, aeolian sand comprising dunes, found above the loess. At about this point, the Montauk Till surface dips below the beach and two additional units are found which outcrop near the upper edge of the beach. The lower unit is composed of laminated silt, clay and fine sand. The upper unit is a peat. Both of these units can be traced for about 0.4 mile towards the east although occasionally interrupted by drift, mostly till, cropping out at beach level. Still further towards the east, the bluffs, composed for the most part of Montauk Till, reappear.
Rooted stumps are occasionally found on the peat layer. About a mile to the northeast, adjacent to East Lake Drive and Montauk Harbor, the U. S. Geological Survey notes 98 feet of clay commencing at elevation 0 (Well S010041). The evidence so far developed suggests the entire Montauk Harbor swale was at one time a lake basin. A pollen section from the beach exposure worked up by Maurice Kalisky, one of our graduate students, indicates the sampled section straddles the B (pine) and C-1 (oak-hemlock) Pollen Zones. In this and other aspects, this pollen section resembles that of Donner's (1964) site 2 section from a bluff 0.3 mile west-northwest of Montauk Point. Apparently, a proglacial lake developed a bog sere in postglacial times which was terminated by the Flandrian transgression. The rise in sea level breached the basin rim and littoral and aeolian sand encroached upon portions of the original basin.

Fort Pond
Fort Pond on your left is dammed on both its north and south side by tombolos.

Montauk Station: eastern terminus of the Long Island Railroad.

STOP 5. Ice contact kame
30 minutes.
This excavation illustrates the internal structure of a morphologically well-defined ice-contact kame. Till is exposed at the north side of the pit while a lag concentrate and loess overlie the glacial drift.

STOP 6. Montauk Sanitary Landfill Project
Both the topographic maps and aerial photographs (see Plate 1) of the Hither Hills area feature several dozen northeast striking ridges. Fuller (1914, p.48), referring to the swales between these ridges, called them "inner-fosse channels". He considered them to be erosion channels which were outlets for waters issuing from the ice margin at successive halts and escaping parallel to the ice front. The structure of the stratified drift exposed in this excavation, however, suggests these ridges are ice-thrust moraines. On the west side of the excavation access road, coarser stratified drift, a lag concentrate, and loess are exposed.

View of the Ronkonkoma moraine
In clear weather, the view towards the west gives an excellent view of the Ronkonkoma moraine as well as many grosser shoreline features.

Wave cut bluff and migrating dunes
Continuing west along Route 27, note the wave-cut bluff to your right (north) now isolated from the sea by a prograding shore. The bluff section consists of stratified drift overlain by dune sand now cascading down onto the Long Island Railroad right-of-way. These dunes appear to have migrated in from the north shore.

STOP 7. "Walking Dune".
At the terminus of the paved road, follow path to top of "Walking Dune".
These magnificent parabolic dunes are the present result of a series of morphological developments. Initially, a spit was built westward out from the north shore of Hither Hills. Foredunes were then built behind the beach associated with the spit. Meanwhile, a tidal marsh sere developed in the lagoon behind the spit and the dunes encroached upon and, in large measure, covered the tidal marsh. An oak forest sere developed within the dune swales but were subsequently covered and still later exhumed. Note the dune slip faces currently burying the existing forest.

Crossing Napeague Meadows, a ditched tidal marsh.
UNGUARDED RAILROAD CROSSING-CAREFUL!

Roadcut through Promised Land Chenier.

Chenier on left (south).
Promised Land fish-rendering plant on right; chenier on left (south). The road parallels the chenier for 1. 5 miles.

The chenier ties into the Ronkonkoma Moraine
The chenier ties into the Ronkonkoma Moraine at the east end of the wave-cut bluff marked by Bluff Road. Presumably, the chenier marks the location of a former spit built eastward at the time the sea was eroding along the line of bluff road.

Wave cut cliff
Bluff Road follows the crest of a wave-cut cliff cut into outwash. Some might suggest that the flat below the bluff represents a mid-Holocene three-meter terrace in the sense of Fairbridge. However, it is more likely that the flat is due to prograding Atlantic shore in this vicinity. The present shore cuts the bluff out at Easthampton village.

STOP 8. Bluff Road.
Plate 2 depicts the morphological relationships of the locality. Time permitting, we will walk the 0.4 mile to the Atlantic shore beach.

G: STRUCTURE AND PETROLOGY OF PELHAM BAY PARK
By Carl K. Seyfert, Department of Geology, Buffalo State University College,
and David J. Leveson, Department of Geology, Brooklyn College.
Location and Geologic Setting.
Pelham Bay Park is located on Long Island Sound in The Bronx in New York City (Figure 1). The area mapped in detail (Scale 1 inch = 10 feet) includes North Twin and South Twin Islands which are located in the eastern part of Pelham Bay Park (Figure 2). Both North Twin and South Twin Islands are underlain by highly deformed and intensely metamorphosed gneisses, schists and amphibolites which have undergone a complex tectonic and metamorphic history involving extensive boudinage, tight isoclinal folding and metasomatism. Pleistocene glaciation and recent wave action provide excellent exposure of bedrock and permit detailed field study of these rocks. The units of Pelham Bay Park were mapped as Hudson Schist (now Manhattan Formation) in the New York City Folio (Merrill et al., 1902). However, on the New York State geological map (Fisher et al., 1961), the rocks are designated as undivided schists and gneisses of unknown age.
Acknowledgments.
The authors wish to thank Professor Kurt Lowe of the College of the City of New York who first introduced them to this area, and the late Professor Arie Poldervaart of Columbia University who provided early encouragement and funds for initial thin sections. Thanks are also due the Society of the Sigma Xi for a Grant-in-Aid of Research that permitted continuing investigation, and the Department of Parks of the City of New York for their courtesy and cooperation.

G: STRUCTURE AND PETROLOGY OF PELHAM BAY PARK

STOP 1. Orchard Beach Park (STOPS 1 - 11)
Turn left and follow the road to the parking lot for Orchard Beach and park in the northeastern corner of the lot.
Distance Between Points.
Take the path which leads to the beach and follow the path along the beach to the northeastern end of the beach. The first stop is on the outcrop just east of the Breakwater on the southern end of South Twin Island (Plate 1).
2400'   STOP 1. The rocks here include felsic gneiss, sillimanite schist, and amphibolite. Note the rootless fold in an amphibolite at the north end of the outcrop (STOP I-A. see Plate 1)0 This amphibolite continues along strike into mafic biotite schist on the west limb of the fold. The west limb of the fold was stretched and thinned during the third phase of deformation. A plagioclase-quartz border is present on the amphibolite near the trough of this synclinal fold.
The amphibolites on the eastern side of the outcrop pinch and swell along strike. Note the presence of pegmatite (Table 1, number IS) replacing the amphibolite and mafic biotite schist (Table 1, number 10) in a thin amphibolite layer which has been separated by boudinage (STOP I-B). Mineralogy of the pegmatite: plagioclase, quartz and biotite.
The amphibolite in the center of the thicker amphibolite layer (STOP I-C) contains little biotite (Table 1, number 6), but biotite increases in abundance toward the contact of the amphibolite (Table 1, number 9) with felsic gneiss.
Isoclinal folds can be seen at the south end of the outcrop (STOP l-C, see Plate 1) especially at low tide. The axial planes of these folds strike N200 E and dip SOOE. Fold axes have an average bearing of N440 E and plunge of 620 NE.
Where folding during the third phase of deformation was particularly intense (STOP I-D), biotite within sillimanite schists was rotated parallel to the axial planes (S3) of the latest set of folds (F3)'
Proceed northeastward along the shoreline.
300'   STOP 2. Rootless fold in amphibolite (See Plate 1). A Plagioclase-quartz border (Table 1, number 11) is present at the ends of the amphibolite which have been separated by boudinage. Near the contact with the plagioclase-quartz border, the amphibolite contains diopside, epidote, calcite and scapolite.
Continue northward along the shoreline.
100'   STOP 3. Small normal fault (Plate 1). Slickensides on the fault plane at the western end of the outcrop indicate that the motion was dominantly dip-slip. Erosion of breccia along the fault has produced a small "rift".
Continue north along the western side of the outcrop.
50'   STOP 4. Pegmatite replacing amphibolite. Note the very irregular, gradational contacts. Mineralogy: plagioclase, quartz and biotite. Continue northeastward along shoreline.
100'   STOP 5. En echelon amphibolite layers suggesting the amphibolites were originally dikes or sills. Note replacement pegmatite in the amphibolite.
Proceed northward along shoreline.
200'   STOP 6. Injection pegmatite dike. Walls are generally sharp, but local assimilation of the felsic gneiss has caused some irregular contacts. Mineralogy: microcline, quartz, plagioclase, with minor tourmaline (black), garnet and apatite.
Note large erratics and glacial striations on bedrock.
75'    Another injection pegmatite (STOP 7 -A). Note straight, parallel walls. Layers of sillimanite schist are offset indicating dilation of the wall rocks during emplacement of pegmatite. Contacts are very sharp and muscovite crystals near the contacts tend to be oriented normal to the walls of the dike. This pegmatite almost certainly crystallized from a granitic melt.
Proceed eastward along the shoreline.
225'   STOP 7. Thick amphibolite layer with calcite-diopside-scapolite pods. This mineralogy is similar to that of the diopside-epidote amphibolites of North Twin Island. Cross the tombolo (which may be covered at high tide except for stepping stones) which connects North Twin Island with South Twin Island (Plate I), Continue to large fold just east of the center of the island.
400'   STOP 8. Folded diopside-epidote amphibolite, plagioclase-rich layers (Table 1, number 15), and calcite-rich layers (Table 1, number 16). Folding is somewhat disharmonic within the calcite-rich and plagioclase-rich layers. These layers grade along strike into diopside-epidote amphibolite on the limbs of the fold (Figure 4). Changes in mineral assemblages going from diopside-epidote amphibolite on the limbs of the fold to plagioclase-rich layers along strike at the crest of the fold are:
(a) hornblende-plagioclase with minor pyroxene, scapolite, epidote and calcite;
(b) plagioclase-hornblende-epidote with minor quartz and pyroxene; and
(c) plagioclase with minor quartz and magnetite.
The plunge of the fold is to the south, indicating that it is an antiform (up-arched foliation surface). However, along strike to the north on both limbs of the fold, the plunge of the folds changes to vertical and then to plunging northward. Thus, there are two antiforms along the continuation of the amphibolite layer, with no intervening synform. Sl foliation has been folded about the antiforms.
Just east of the fold, there are several plagioclase-biotite gneiss layers within the diopside-epidote amphibolite (STOP 8-B). Ellipsoidal hornblende nodules occur within diopside-epidote amphibolite near the contact with plagioclase-biotite gneiss on the eastern side of North Twin Island (STOP 8-C). The nodules are 2 to 4cm. in length and 1 to 2 cm. across 'and lie in a calcite matrix. They are separated from the calcite by a 2 to 5mm. wide zone of medium-grained pyroxene and scapolite. A thin rind of epidote surrounds some scapolite grains and separates them from adjacent calcite. Intermediate axes of the ellipsoids are parallel to the foliation and long axes are parallel to mineral lineations in the surrounding mafic gneiss.
Diopside-epidote amphibolite grades along strike into normal amphibolite (STOP 8-D) suggesting that it formed by metasomatism of amphibolite.
Proceed northward.
STOP 9. Replacement Pegmatite. Plagioclase and microcline porphyroblasts are abundant within plagioclase-biotite gneiss near the contact with replacement pegmatite (Table 1, number 17). In fact, the replacement pegmatite is simply a coalesced mass of porphyroblasts. Contacts are gradational and extremely irregular.
Note the plagioclase-biotite selvage surrounding a diopside-epidote amphibolite boudin at the contact of the boudin with replacement pegmatite (STOP 9-A).
A plagioclase-epidote-quartz border is present at the end of a layer of diopside epidote amphibolite which has been separated by boudinage (STOP 9-B). This border grades abruptly along strike into amphibolite (very thin border) and then into diopside-epidote amphibolite. Relict foliation (Sl) is present in the plagioclase-epidote-quartz border. The border, which is 87% plagioclase, 5-1/2% quartz and 4% epidote, developed by metasomatism of diopside-epidote amphibolite. The composition (Table 1, number 12) is similar to that of an anorthosite.
Proceed to the northwest.
75'   STOP 10. Boudins of diopside-epidote amphibolite within plagioclase-biotite gneiss. There are several areas where diopside-epidote amphibolite can be traced along strike into plagioclase-biotite gneiss suggesting that the plagioclase-biotite gneiss was produced by metasomatism of diopside-epidote amphibolite. Steps involved are:
(a) feldspathization of diopside-epidote amphibolite;
(b) conversion to feldspathic amphibolite; and
(c) replacement of hornblende by biotite, forming plagioclase-biotite gneiss.
Calcite-rich layers and pods are present within diopside-epidote amphibolite boudins. Calcite-rich layers are also abundant at the ends of the diopside-epidote amphibolite layers which have been separated by boudinage (STOP 10-A). The zone containing calcite rich layers is 25 feet wide, but it grades along strike (to the south) into diopside-epidote amphibolite containing no calcite-rich layers. This suggests that the calcite-rich layers were produced by metasomatism of diopside-epidote amphibolite.
Note the curved mineral lineations and curved fold axes within the boudins (STOP 10-B). The rotation of lineations and fold axes occurred during "necking" prior to separation of the boudins.
Return to South Twin Island and follow the western shoreline to a gravel road near the center of the western shoreline of the island.
1000'    Take gravel road westward across the bridge to Hunter Island.
900'     Turn right (north) along the east shore of Hunter Island to a small outcrop of felsic gneiss and sillimanite schist just south of a thick amphibolite layer (Figure 2).
1000'   STOP 11. Open fold. Felsic gneiss, sillimanite schist, and biotite amphibolite show evidence of 3 phases of deformation because in this area the last phase of deformation was not intense enough to obliterate signs of the earlier deformations. Biotite and amphibole crystals are oriented parallel to compositional layers within the biotite amphibolite. This foliation (S1) is probably an axial plane foliation formed during an early period of intense deformation. This foliation has been folded about a set of fold axes (L,z) which plunge steeply to the southeast. Large amphibole crystals are oriented parallel to these fold axes. A second foliation (S2) is defined by biotite crystals oriented parallel to the axial planes of the F2 folds within the felsic gneiss. Within sillimanite schist, biotite and sillimanite are oriented parallel to the axial plane (S3) of the latest set of folds. Axes of these folds plunge steeply to the northeast in this area. The relation between the folds and foliations is shown in Figure 5.
Return to the gravel road by taking path southward along the shoreline.
1000'   Take gravel road south to fork in the road.
800'     Take right hand fork and return to the parking lot. We will eat LUNCH on the tables just north of the parking lot.

H: STRATIGRAPHIC AND STRUCTURAL RELATIONS ALONG THE WESTERN BORDER OF THE CORTLANDT INTRUSIVES
Nicholas M. Ratcliffe
City College of New York
INTRODUCTION AND PURPOSE OF TRIP
The New York State Geological Association as recently as 1958 dealt specifically with the problem and areas outlined in this discussion. Recent discoveries by Hall (1965, and this volume), however, have brought the stratigraphic problems of the New York City Group much more clearly to light and have encouraged re-evaluation of the field evidence in this critical area.
The stratigraphic age and correlation of the rocks surrounding the western edge of the Cortlandt intrusives has been clouded by the personal prejudices of individual workers for many years. Because definitive evidence of a stratigraphic kind is difficult to come by in an area as complexly deformed as this, this correlation problem of regional importance is not resolved at the present time.
This trip will focus on one major problem: are the rocks called Manhattan Schist and Inwood Marble south of the Cortlandt intrusives correlative with fossiliferous rocks at Tomkins Cove and Verplanck Point? Lithic and structural arguments will be presented to support this correlation. As in all metamorphosed areas, we must rely primarily on lithic characteristics and stratigraphic succession as well as on structural continuity to solve this kind of problem. The answer is to be found in the rocks; all we must do is look for it.
The purpose of this field trip is to present new stratigraphic and structural data from the western border of the Cortlandt intrusives. This area is critical because it is the locality where correlation of Manhattan Schist and Inwood Marble with the low-rank carbonate rocks and phyllites at Tomkins Cove can best be accomplished. Bucher (1951) demonstrated the lower Paleozoic age of the Tomkins Cove section on the basis of pelmatozoan fragments in a calcareous zone at the base of the phyllite section there (STOP 7-A).
A similar fossiliferous zone rich in pelmatozoan remains has been discovered at Verplanck Point Quarry, on the east side of the Hudson River, demonstrating a Lower Paleozoic age for these rocks (Ratcliffe and Knowles, 1968) (STOP 5). A very similar "crinoidal" limestone is interbedded with the base of the type Annsville Phyllite in the Peekskill Hollow Creek at Van Cortlandtville 1-3/4 miles north of Peekskill. Identifiable fragments of pelmatozoan columnals were found in this rock by participants in the NYSGA excursion of 1958, thus supporting the correlation of Annsyille Phyllite with the phyllites at Tomkins Cove proposed on lithic grounds by Bucher (1951). It is here suggested that the lower unit of the Manhattan formation is correlative with the combined Balmville Limestone and Annsville Phyllite and that both are Mid-Ordovician in age.

H: STRATIGRAPHIC AND STRUCTURAL RELATIONS ALONG THE WESTERN BORDER OF THE CORTLANDT INTRUSIVES

Large outcrops of Yonkers-type gneiss
Note large outcrops of Yonkers-type gneiss with large apparently folded pegmatites.

Numerous exposures of Xma
Continue north along 9A around west end of Prickly Pear Hill. Numerous exposures of Xma (Upper Manhattan, here staurolite grade). Just entering map, Figure 1.

STOP 1. Brinton Bird Sanctuary.
North flank Prickly Pear Hill, NE 1/9 Haverstraw Quad.
This stop is located on the southeast flank of the Tomkins Cove Crugers F1 anticline (Figures 1 and 3), and exposes granitic gneisses of the Fordham Gneiss in near contact with the Lower Manhattan (Oma).
Walk northeast up the path into the bird sanctuary approximately 800 feet to large glaciated exposure of Manhattan schist.
Garnet-quartz-biotite-muscovite-schist and garnet-biotite-muscovite-plagioclase-quartz granulites are the dominant lithologies. Staurolite is a diagnostic mineral in much of Unit B of the Manhattan in this area. This is typical of the Upper Manhattan exposed to the southeast on Prickly Pear Hill and resembles the type Manhattan of New York City despite the lower metamorphic grade.
Closures of F1 folds may be seen in the outcrop with the F1 axial surfaces (with bedding parallel in most cases) trending N45°-50° E and dipping steeply to the east. Late F2 folds with a related crenulation cleavage trend S75°-80°E and have near vertical axial planes and fold the F1 axial surfaces.
An F3 fold system is weakly developed in the north-central portion of the outcrop with axial planes trending S45°-50° E.
Note the several generations of quartz veins, parallel to S1, S2, and S3. S3 quartz is located in short gash-like fractures, suggesting the brittle behavior of the late F3 structure. Note the habit of the large post-kinematic metacrysts of biotite (plates are not oriented in S1, S2, or S3), S1 foliation is developed largely by the orientation of the white mica and lenticular quartz grains.
Walk north into open field to small outcrops of Lower Manhattan. Black, sooty appearance is typical of the Lower Manhattan. Minor dark siliceous layers are common.
Continue north across field noting scattered small outcrops of Lower Manhattan.
Near the edge of the field to north and by stone wall are outcrops of granitic gneiss of the Fordham. Foliation having the orientation of S1 in the schist is present in the gneiss. Compositional layering is difficult to see in the gneiss at this locality, but it commonly is not parallel to S1 (i.e., S1 is superposed on an earlier, probably Precambrian, foliation in the gneiss). There is little room here for the Inwood formation. This gneiss - Lower Manhattan contact has been mapped along the north side of Prickly Pear Hill to a point east of the lake where compositional layering in the gneiss demonstrates the anticlinal closure (see Figure 3).

Outcrops of layered gneisses of Fordham Gneiss
Overpass to Oscawanna on left (roadcut N. Y. 9) outcrops of layered gneisses of Fordham Gneiss dips are north at moderate angles. Granitic gneiss of Fordham can be seen at north end of cut. Underpass for N.Y. 9. Pass exposures on right (east) of layered norite.

Pass outcrops of Manhattan (Xmb) in woods above road.

STOP 2. Maiden Lane Sand Pit.
This stop is located on the opposite (north) limb of the major F1 fold from STOP 1 (Figure 3). Walk into the sand pit starting from the intersection of Maiden Lane and Cortlandt Street.
Layered biotite, plagioclase gneiss is exposed at corner. Foliation and compositional layering dip steeply to the north. Granitic gneiss of the Fordham is exposed in stream bed and on the hill to the south of the stream.
Enter sand pit east of house. The sand pit exposes a section that is a maximum of 50 feet thick, from Fordham Gneiss to the base of the Manhattan Formation.
Walking north into pit, one encounters the various rock units.
Biotite-plagioclase-quartz-gneiss (Fordham)
Lowerre quartzite (right-side-up) 15 ft.
Unit A Inwood white dolomitic marble 10-15 ft.
Unit B Inwood - impure siliceous dolostone with phyllitic layers 20 ft.
Manhattan (Oma) - calcareous, siliceous black metagraywacke, biotite-quartz-plagioclase schist, and lustrous garnet-staurolite-muscovite, biotite quartz schist.
The lower units of Oma are characterized here by concentrations of pale green tourmaline with khaki green overgrowths. Similar zoned tourmalines are present in Oma at STOP 3 and again at Verplanck Quarry (STOP 5).
The dominant foliation S1, sub-parallel to bedding, varies from N80&deg-90 °E and dips 70°-80° to the north. S2, here a well developed foliation (N80°E, 85°S), folds S1 producing east-plunging folds of S1 and S0.
A locally well-developed S3 crenulation cleavage, (N45°-50°E, 90°) cuts S2 and S1 surfaces on a small exposure of Lower Manhattan above the sand pit.
Typical Upper Manhattan (Xmb) can be seen above the sand pit to the northeast. Note abundant refolded F1 folds; east plunging F2 folds dominate the structure. Staurolite-garnet-muscovite-biotite-quartz-plagioclase schists and typical garnet-muscovite-biotite-plagioclase-quartz granulites of the Upper Manhattan are exposed. Kyanite has been found with staurolite in exposures of this unit 300 feet east of this outcrop.

STOP 3. Crugers.
The purpose of this stop is to visit excellent exposures of B type Inwood and to see the Manhattan - Inwood contact.
Begin by walking down to Hudson River behind houses to sandy dolostones of Unit B. Compound folding is common here. Thin orange weathered quartzites are common in the dolostone. Rocks similar to this will be seen at Stony Point on STOP 7. Dolostones of Unit B are best exposed in the railroad cut.
Walk north to the FDR Hospital grounds and northwest along Hudson River to small point.
Here is an excellent exposure of the Inwood formation and Lower Manhattan (Oma) contact. Note the lithic characteristics diagnostic of Lower Manhattan seen on STOPS 1 and 2. A thin 2 to 3 inch coarsely crystalline calcareous marble occurs at the contact with the schist. Beneath this a zone of interlayered gray and white, crystalline, calcitic dolostone and calcite marble is exposed before massive, beige-weathered dolostones at the waters edge. Thin orange quartzites in the beige-weathered dolostones suggest this is Unit B. A thick section (200-300 ft.) of Unit C mapped to the east is not present here.
Walk east along contact. Note minor transverse faults and tectonic breccias filling fault planes (late state effects of Cortlandt intrusions, perhaps). Isoclinal F1 folds are common along the contact zone to the east.
Walk up section to foot path. Note here black and white striped calcitic schists of Manhattan Unit A. This is a very distinctive lithology seen in many places just above the base of Unit A . An excellent exposure of this can be seen at the north end of a roadcut on new Route 9 at Prickly Pear Hill (NE 1/9 Haverstraw Quad. ). Common mineral assemblages and texture in Oma at this locality are lepidoblastic muscovite and biotite (parallel to S1)-quartz-plagioclase-calcite-garnet.
Upper Manhattan is exposed above on a hill. Note change in color of the rock and in bedding characteristics. Lepidoblastic biotite and muscovite are common along with garnet, quartz, and plagioclase. Staurolite is present in some layers.

STOP 4. George's Point.
Excellent exposures of Upper Manhattan (Omb) granulites and schists. F1 folds are well exposed and dip steeply to the northeast and are mildly folded by late northeast plunging F2 folds.
This point is located between a large dioritic mass to the east and a pyroxenitic-noritic mass to the northwest (Montrose Point). The late F2 folds may be a result of shouldering aside of the country rocks by one or both plutons. These schists belonging to the Upper Manhattan will be seen at Verplanck on STOP 5 and again at Stony Point on STOP 7.
Garnet-biotite-muscovite-plagioclase-quartz is the common mineral association. No staurolite has been found here.

STOP 5. Verplanck Point Quarry (for location see Figure 1).
The contact between Unit A of the Mmhattan Formation (compare with STOPS 1, 2, and 3) and the Inwood Formation is exposed in the east wall of the quarry.
Climb over the wall carefully. a few at a time. Pelmatozoan fragments are abundant in a blue-gray crystalline limestone at the base of the Manhattan. Abundant isoclinal (F1) folding repeats this zone several times. One excellent stem plate is preserved in the crest of a small S1 isocline beneath the overhang. NO HAMMERING PLEASE! F1 axial planes strike N35°-40°E and dip 50°-60° SE. F1 plunges are moderately steep to the southwest. F2 crenulation cleavage is incipient and weakly folds the F1 axial planes. Axes of F2 plunge S25°-30° E at 45°-50°.
The intensity of F2 folds increases toward the complex.
Note the distinctly phyllitic texture of the rock. Biotite-muscovite-quartz- calcite-plagioclase-garnet is the common assemblage. Biotite usually predominates over muscovite. Both are perfectly oriented in S1 and folded by S2. An interesting bed two feet from the marble contains abundant red-brown biotite, garnet, and minor amounts of staurolite. Very distinctive green tourmaline with khaki overgrowths is an accessory mineral in most specimens of Oma here.
Walk north along rim. Excellently exposed F1 folds are shown by limy interbeds in the Lower Manhattan.
The north face of the quarry exposes white dolostone closest to the schist, assigned tentatively to Unit C of the Inwood Formation. The main layered dolostone in the quarry is characterized by dark dolostones with black phyllitic partings and thin quartzite stringers. Weathered surfaces are cream or beige. These rocks are assigned to Unit B of the Inwood Formation.
If time allows, we will walk west to the Hudson River down cliffs of sandy dolostones of Unit B to white crystalline dolostones exposed at the river's edge that probably belong to Unit A of the Inwood Formation.
A change from the staurolite-almandine subfacies of the almandine-amphibolite facies (at Verplanck quarry) to the quartz-albite-epidote-biotite subfacies of the greenschist facies (Tomkins Cove) takes place over a distance of 1.5 miles. This is a rather steep metamorphic gradient in regionally metamorphosed areas. For example, from biotite to staurolite isograds in Dutchess Co. is three miles (Balk, 1936).
Staurolite generally is ascribed to regional metamorphism because of the relatively high pressures thought to be necessary for its formation (Winkler, 1965). However, staurolite has been reported from the aureole of a shallow level granitic pluton (Rastall, 1910). Moreover, Winkler (1965, p. 109) believes staurolite with almandine might be expected in restricted areas bordering deep level plutons.
Metacrysts of staurolite and almandine in the Lower Manhattan Formation at Verplanck Point Quarry have textures indicative of post F1 crystallization and may have formed synchronous with or later than the F2 fold system. These observations are consistent with an hypothesis attributing the garnet and staurolite to contact effects induced by intrusion of the Cortlandt intrusives. Contact metamorphism under high confining pressure might be the cause of the steep metamorphic gradient seen here.
LUNCH STOP

STOP 6 (end of road). (Beware of dogs.)
Small outcrop of Upper Manhattan (Omb) - typical granulites very similar to George's Point (STOP 4). Note folded F1 folds and strong development of F2 structures. Fracture fillings in S2 probably are related to increased grade of contact metamorphism as Cortlandt intrusives are approached. Compare intensity of F2 structures with STOP 5, and note the similar orientation.

STOP 7. Tompkins Cove - Stony Point (see Figure 4 for location).
A. Railroad cut by DarkSeaGreen and Rockland plant north of quarry. Exposed on west wall is interbedded Lower Manhattan (Oma) and "crinoidal" limestone unit seen at STOP 5. Isoclinal F1 folding is common. Note refolded F1 fold and steep plunges of F1 folds.
B. Walk into main quarry. The contact of the "crinoidal" limestone unit with underlying (stratigraphically) white dolostones is exposed on the west slope of the quarry. Adventurous ones may climb up to see a truncation of S0 in the dolostone by the limestone. Is this sedimentary, or tectonic and the result of flowage? Be very careful of those following you; do not dislodge loose blocks.
From the quarry walk east to the railroad tracks and walk south toward Stony Point. Exposures of sandy dolostones, perhaps Unit B of the Inwood Formation (tops east?).
C. First outcrops are biotite diorite of the Cortlandt Complex. Climb up hill to exposure of contact with Lower Manhattan. Note discordant contact and non-foliated igneous rock and apophyses.
D. Walk south along ridge toward Cortlandtite pluton to contact with Oma. Note brecciated rock close to Cortlandtite. Fragments of foliated biotite schist float now in a matrix of K-feldspar-sillimanite-garnet and quartz. This sillimanite zone is very thin, perhaps 10 feet thick. Closest to schist is a green hornblende-rich contact phase developed around the pluton at the contact with either diorite or schist.
E. Walk down to road to west. Follow road south. Note small outcrops of limestone. Exposures of calcitic marble and Lower Manhattan (Unit B) on slopes above pond. This is metamorphosed equivalent of the crinoidal zone exposed on the west flank of the anticline. The very distinctive Oma here is a biotite-muscovite-quartz-plagioclase phyllite.
F. Continue to the south to road. Cross swamp to base of ridge to south. Exposures of carbonate rock on hillside. Probably Unit B of the Inwood Formation. Note the position south of the intrusives and its relation to STOP 3 at Crugers. The carbonate rocks close around the south side of the Cortlandt rock at Stony Point.
Walk east along carbonate outcrop to railroad tracks. Then head north along railroad toward intrusives.
G. Railroad cut in Upper Manhattan (Unit B). Shown here are dikes cross-cutting F1 and F2 folds. The contact with Cortlandtite pluton is exposed at the north end. Follow cross-section, Figure 6, for location on east wall. If a train comes, you will be warned. Please move promptly to the west side of the cut where there is plenty of room. Don't panic!
Continue north to see near vertical contact of the Cortlandtite with the schist. Note contact zone with minor drags, indicating north-up rotation sense. The hornblendite zone seen at STOP 7-D passes into typical north-dipping layered Cortlandtite 20 feet from the contact. Immediately above to the east on the slopes (see light colored soil zone) are exposures of calc-silicates of the basal Manhattan, exposed in an F1 isoclinal fold that is truncated by the Cortlandtite pluton. F2 folds are E-W perpendicular to Cortlandtite contact. The type locality of Cortlandtite (Williams, 1886) is located on the north shore of Stony Point near the swimming pier.
In the time remaining feel free to wander into the Park where there are excellent exposures of the biotite diorite with late cross-cutting lamprophyres and still later aplitic dikes. Flow structure and xenoliths can be seen in the biotite diorite. No hammering on exposed surfaces in the Park, please.
Meet bus at Stony Point Park.

I: DEEP-WELL INJECTION OF TREATED WASTE WATER--AN EXPERIMENT IN RE-USE OF GROUND-WATER IN WESTERN LONG ISLAND, N. Y.
By N. M. Perlmutter, F.J. Pearson, and G.D. Bennett
U. S. Geological Survey, Mineola and Albany, N.Y.
Publication authorized by Director, U.S. Geological Survey
Work done in cooperation with the Nassau County Department of Public Works.
No Road Log

J: GEOLOGY, GEOMORPHOLOGY, AND LATE-GLACIAL ENVIRONMENTS OF WESTERN LONG ISLAND, NEW YORK
OR
SUBURBAN PLEISTOCENE GEOLOGY: WHO BUILT A PARKWAY ON MY BOG?
By Leslie A. Sirkin, Adelphi University.
The glacial geology and geomorphology of western Long Island were first studied in detail by Woodworth (1901) and Fuller (1914). Supplementary and more recent work has been contributed by de Laguna and Perlmutter (1949), Swarzenski (1963) and Perlmutter and Geraghty (1963), among others. The reconstruction of late-Wisconsin and postglacial environments in western Long Island is based mainly on the relationships between the glacial deposits, geomorphology, and radiocarbon dated pollen stratigraphy. The pollen stratigraphy and chronology for this region (Sirkin, 1965) show consistent similarities to the late-glacial and postglacial pollen stratigraphy and chronology of southern New England (Deevey, 1958) with notable exceptions: (1) a longer and presumably more nearly complete late-glacial record is found in the vicinity of the terminal moraine (i. e., near the southern limit of late-Wisconsin glaciation), (2) deglaciation began earlier in the terminal moraine region than to the north in New York and New England, (3) the pollen record-begins with pollen spectra indicative of park-tundra vegetation, rather than the high Arctic tundra suggested in southern New England (Leopold, 1956; Ogden, 1959), and (4) the pollen zones, at least through subzone B2 (pine, oak), begin earlier in western Long Island and are time transgressive into southern New England. Finally, correlation between the pollen record, glacial geology, and geomorphology provides a means of interpreting the late-glacial physical environment.

J: GEOLOGY, GEOMORPHOLOGY, AND LATE-GLACIAL ENVIRONMENTS OF WESTERN LONG ISLAND, NEW YORK

Flushing Bay
Note crossing Flushing Bay, a glacial trough which may be linked to the Bronx River valley on the Bronx side of the East River.

STOP 1. Alley Pond Borrow Pit.
This exposure provides an opportunity to observe the lithology and structure of the Harbor Hill Moraine, (Plate 1, figure 1), the till (upper 5+ feet), the Little Neck Bay trough, and from the top of the cut, the New York skyline. Long axes of pebbles from the till point generally NNW, Note: The extension of Little Neck Bay with Eastchester Bay and the Hutchinson River in the Bronx to the north; the drumlinoid hills - Fort Totten on the west side and Douglaston on the east side of Little Neck Bay. Occassionally, the stratified drift below the till is exposed in gullies. A section is also exposed at the northeastern corner of the Korvette shopping center, below 251st st. North of the L.I.E. a small lobe projecting from the valley wall on the east side was dissected in construction. It may have been a small kame. Alley Pond bog is on top of the moraine on the west side of the valley.

LOOK STOP. Lake Success.
A kettle lake about 0.4 miles across and about 75 feet deep; several small kettles are located on the west and south sides of Lake Success.

STOP 2. Lakeville Road - Northern State Parkway.
A recent cut for widening of the parkway has exposed a section of the Harbor Hill Moraine comprised of about 5 feet of Harbor Hill till overlying 20+ feet of stratified lacustrine sands with thin clay partings (Plate 1, figures 2,3 and 4). A lake history is suggested since the results of examination for marine microfossils was negative. No other evidence for a high marine stand effecting deposition along the moraine has been found, other than the suggested wave cut cliff along the distal slope of the moraine (Woodworth, 1901). The kettle topography north and east of this site suggests that the stratified fine grained section was deposited in an ice dammed lake on the distal slope of the moraine at the junction of the outwash plain. Other large kettles developed on the pitted outwash just south of the moraine. This section is located near the junction of the Harbor Hill and Ronkonkoma moraines which may have some relationship to the stratigraphy if ice movement pivoted at this point, calving-off large ice blocks.

STOP 3. Willis Avenue - Northern State Parkway.
In this cut, northeast of the intersection, a section of 4 to 8 feet of till overlies 10+ feet of cross bedded sands and gravels and very coarse cobbles. (Plate 1, figure 5) This section is in the Ronkonkoma moraine and demonstrates the superposed till (cf.the Harbor Hill Till) over outwash and the kame like nature of the moraine.

STOP 4. Roslyn Road - Northern State Parkway.
Another cut into the Ronkonkoma Moraine, on the northeast side of the road, has exposed the lower till (cf. the Montauk Till). Approximately 10 to 15 feet of till are overlain by 25 to 30 feet of coarse cobbly, outwash (or Kame) deposits (Plate 2, figures 1 and 2). The till when exposed in a drainage trench appeared to grade downward and southward into sandy lenses.

STOP 5, Harbor Hill, Roslyn.
Harbor Hill is the type locality of the Harbor Hill Moraine and the Harbor Hill Till. The contact between the till and the outwash may be examined here (Plate 1, figure 6). The hillside just northeast of Route 25A (on the east side of the bridge) is underlain by a kame (Swarzenski, 1963). Observe the Hempstead Harbor trough and the borrow pits along the west side of the Harbor in Port Washington. Flower Hill bog is above the borrow pits and is being cut into at this

ALTERNATE STOP 6. Garvies Point.
Described at STOP 6, ahead, and in text.
The Preserve, a Nassau County facility, is set aside for archaeologic studies, and in addition to exposures of Cretaceous and Pleistocene deposits in the cliff sections, contains paleo-Indian shell middens and a possible Indian fishing site in the Cove. Typically, red, gray, and white clay with lignite lenses, marcasite nodules, and fossiliferous (plants) siderite nodules are exposed at the base of the cliffs. The plant fossils include woody fragments and leaves of fig and magnolia. Preliminary pollen and spore analysis of the clays indicates Raritan or possibly Magothy age. The clays are overlain by a white sand section and/or outwash and/or till (Harbor Hill ground moraine or recessional till) (Plat8 2, figures 3 and 4). The attitude of the slump blocks is evident here.

STOP 6. Police Rifle Range, Port Washington.
A stratigraphic section, measured in detail by students of Dr. David Krinsley, Queens College (Dr. Krinsley, personal communication) include from the base: 14 feet 2 inches of poorly sorted, pebbly, medium grained sands, 40 feet 10 inches of white sands, which are often pebbly and streaked with iron and manganese oxide stain, and about 15.5 feet of alternating light and dark sands and gravels. The age of the "white sand" layer is questionable, since it is reportedly unfossiliferous (although Dr. Walter S. Newman reports one Cretaceous spore from this horizon).
Observe Mosquito Cove - Glen Cove Creek to the ENE across the Harbor. This inlet and the low break in the cliffs north of the Rifle Range constitute a portion of the east-west drainage along the glacial stillstand referred to in the text. The Cretaceous crops out at Garvies Point on Mosquito Cove and in the Morgan Park north of that site, but it is not exposed north of the borrow pit. The cliffs to the north in Sands Point are composed of 20 to 40 feet of outwash overlain by a thin layer (5+feet) ground moraine.

STOP 7. Manhasset Valley Park - Manhasset.
At this stop, one, or possibly two, separate kames (or kame deltas) are found mantling the moraine consisting of thin till over outwash. The outwash is apparently folded or has flowed (Plate 2, figure 5) and is occasionally exposed in building excavations on Northern Boulevard (Route 25A). The till is probably recessional or ground moraine of late-Harbor Hill age. The kames exhibit striking ice contact structures (Plate 2, figure 6) and indicate a late Harbor Hill glacial advance which sent tongues of ice up the troughs. This advance is supported by several lines of evidence:
(1) the presence of kames at the valley heads.
(2) sculpturing of peripheral deposits (i.e. the drumlinoid hills) and deformation of cliff sections (although the outwash may also have been deformed during the initial Harbor Hill advance).
(3) Oscillation in the pollen record: The subzones W2 - W3 sequence indicating the stillstand and the return of cold indicators in subzone T1.
(4) the stillstand evidence including the "deltas" of Woodworth (1901) and the E-W drainage lineation (Figure 1).
Tracing the deposits clockwise around the exposure, observe the kame, next (above the wall) outwash (thin till at top) and kame (fronting on 25A behind gas station).

Note the drumlin (possible) south of lake on east side of road.

Note cuts into the moraine
Note cuts into the moraine while ascending the trough on the proximal slope of the Harbor Hill Moraine.