NYSGA 1975
GUIDEBOOK
to
FIELD EXCURSIONS
conducted at the
47th MEETING
of the
NEW YORK STATE GEOLOGICAL ASSOCIATION
October 3l-November 2, 1975
Hanfred P. Wolff, Editor
Host
Hofstra University
Department of Geology
Hempstead, New York
ACKNOWLEDGEMENTS
This guidebook provides a permanent record of the 47th meeting of the New York State Geological Association. The papers and road logs are presented to enhance the various field trips, to allow participants to read through them at their leisure. and to later make a return visit whenever they desire. For the most part they summarize previous information and/or provide new data and concepts that reflect continuing research in the New York City-Long Island-New Jersey region.
The trips vary from bedrock geology and stratigraphy to coastal and glacial geomorphology -to excursions of areas containing earth, energy, and environmental resources -to ocean voyages. Because of time implications some trips (particularly on Long Island) cannot later be completed in the exact manner described herein. The interplay between man-made and geological influences will continue to alter these areas, for better or worse, and whenever possible, modern management techniques and environmental considerations have also been included.
The shortness of available time for preparing the guidebook has not given the authors an opportunity to see proofs of their articles, and the editor accepts any responsibility for errors that may appear. Editorial changes were kept minimal in most instances. Special acknowledgement is made to the many authors from neighboring institutions without whose help this guidebook and meeting would not have been possible. The effort can only be appreciated by those who have made similar contributions to this meeting over the years.
For individual efforts in organizing the format of the guidebook and logistics for the meeting, special thanks to Dr. Kurt E. Lowe, Professor Emeritus at City College of the City University of New York. Dr. Lowe has long been a prominent figure in the association and consented to be our guest lecturer for the banquet at this meeting.
For her assistance in preparing the guidebook, and making all the detailed arrangements for transport, food and lodging, special thanks and appreciation also go to Mrs. Margaret L. Johnson, the Geology Department secretary who took it upon herself to gather the information for organizing the field excursions.
The editor would also like to thank Ms. Christine Anderson (President), and the other geology majors and members of the Long Island Geological Society (Hofstra's Geology Club) who contributed their time and effort toward making this a successful meeting, and Dr. Usman A. Sayeed for drafting the guidebook cover.
Manfred P. Wolff Editor and President, 1975

A1: STRATIGRAPHY, STRUCTURE AND PETROLOGY
OF THE NEW YORK CITY GROUP
Simon Schaffel
Department of Earth and Planetary Sciences
City College of C.U.N.Y.

A1: STRATIGRAPHY, STRUCTURE AND PETROLOGY
OF THE NEW YORK CITY GROUP

Terminal moraine
Terminal moraine occurs directly to the right (north). The moraine is either the Ronkonkoma capped by the Harbor Hill or an undifferentiated mixture of both.

Terminal moraine, Port Washington delta
Terminal moraine on left (south) with Port Washington delta
on right (north). The latter feature formed as a result of a periglacial lake forming behind moraine and fronting the ice.

Pass onto top of moraine.
Pass onto top of moraine. Typical glacial knob and kettle,
hummocky-type topography.

Pass through valley of Little Neck Bay
Pass through valley of Little Neck Bay, which lies north-south of the expressway. This valley, although covered with a veneer of glacial till represents an initial preglacial valley. It is one of several north-south trending valleys which occur along the north shore of Long Island and undoubtedly represent obsequent valleys to the subsequent valley occupied by Long Island Sound.

Continuous exposures on both sides of expressway.
Lithology composed of mica schists with subordinate amounts of sillimanite schists and biotite-quartz gneisses. Minor folds common exhibiting chevron pattern. Fold axes and other linear elements plunge northward (15 - 50¬∞). These units have been designated as "undifferentiated schists and gneisses" on the 1961 edition of the New York State Geological Map. Hall (1968b) referred to them as Hartland-Manhattan undivided. Seyfert and Leveson (1969) placed them in their own coined "Hutchinson River Group."

Bronx River valley.
Boundary between the eastern undifferentiated schists and gneisses and the New York City Group to the west. Boundary is believed to be a major stratigraphic-structural break.

Continuous exposure of Manhattan schist
Continuous exposure of Manhattan schist on both sides of expressway forming Crotona Park synclinal ridge.

Cross Park-Webster Avenue valley.
The valley is underlain by Inwood marble. This north-south low is the former valley of the Bronx River. The stream was evicted from its original course further north into its present valley.

Anticline of amphibolite member of Manhattan schist
Anticline of amphibolite member of Manhattan schist immediately to right. This unit is approximately 20-30 feet thick and about 50-60 feet above the Inwood-Manhattan contact.

STOP 1. GRAND CONCOURSE SYNCLINAL RIDGE
Manhattan schist occurs along the north-south trending Grand Concourse forming a ridge while the lesser resistant Inwood marble forms the valleys on both sides of the ridge. Manhattan schist-Inwood marble contact is present along south side (east bound lane) of Cross-Bronx Expressway. Typical interbedding of Inwood and Manhattan along west ridge slope can be seen.
Inwood marble is a gray to buff-colored, medium to coarse textured marble and dolomitic marble. Bed thickness varies from 1/2" to 6 feet. Minor amounts of graphite, pyrite, phlogopite, tremolite and diopside have been found. Thickness of the formation varies but here it occupies the entire Jerome Avenue valley - approximately 1000 feet. Repetition of beds by folding is possible.

Continuous exposure on south and north side of expressway.
FORDHAM GNEISS forming Highbridge prong of Fordham ridge. This ridge is one of the type localities for the Fordham in New York City. The ridge is an overturned anticline to the west.
Lithologically the unit is a biotite-feldspar-quartz gneiss. The three minerals form alternating bands which vary from inches to three feet. Band is very uniform and consistent. Plagioclase feldspar is common but subordinate to the potash feldspar. Intercalated bands of granite pegmatites, amphibolites, and marbles occur. Bands (layers) are steeply dipping (60-90°) to the east. Small minor folds are common. Larger isoclinal and asymmetrical folds can be detected with axial planes overturned toward the west. All fold axes plus other linear elements plunge south at approximately 15°.

Cross Harlem River, separating Manhattan and Bronx.
The Harlem is not a river but a strait. The entire valley is underlain by steeply dipping, tightly folded beds of Inwood marble.

STOP 2. BASE OF COOGAN'S BLUFF
Carefully cross the highway to base of cliff and walk north to fresh exposure of Manhattan schist. Amphibolite (Hornblende schist), and Pegmatites.
Merrill et al. (1902) cites this as a type locality for the Manhattan schist. The principal lithology is a coarse textured light to dark-grey biotite muscovite quartz schist with sporadic high concentrations of garnet. Other minor minerals in order of abundance include plagioclase (oligoclase), potash feldspar (orthoclase), magnetite, pyrite, and sillimanite. Pods (augens) of quartz and feldspar, where quantitatively significant, may develop a gneissoid appearance. Axes of minor and major folds within the schist as well as other linear elements plunge south about 15°.
The Amphibolite (Hornblende schist) here is a dark grey to black medium texture rock. Principal minerals include hornblende and plagioclase (andesine) feldspar with local high concentrations of epidote. A rhombohedral-type jointing is the result of the dense and close parallel arrangement of the prismatic shaped hornblende crystals. This jointing contrasts with the block type peculiar to the Manhattan schist and Fordham gneiss. The Amphibolite bed here is approximately 30-60 feet from the Manhattan-Inwood contact and is believed to he the same bed viewed at Mile 26.2 earlier. This Amphibolite appears to be an excellent horizon marker for locating the Manhattan-Inwood contact in the region.
The "Pegmatites" found in the New York City Group are composed of granites, granite pegmatites, graphic granites, aplites, and quartz veins. These concordant and discordant bodies occur in all formations with varying widths up to 10 feet. Quartz, pink microcline feldspar, greenish oligoclase plus muscovite are the common principal minerals. Biotite, hornblende, magnetite, garnet, black tourmaline are some of the minor constituents.

Dyckman Street fault.
One of the few cross faults found in New York City resulting in an east-west cross valley.

STOP 3. INWOOD PARK-ISHAM PARK
Proceed west into Inwood Park. The canoe-shaped valley underlain by Inwood marble is an anticline while the two adjacent Manhattan schist ridges are synclines (Figure 3). Amphibolite exposure occurs along the path leading to the western ridge. Spuyten Duyvil, the water body immediately to the north is at present a strait connecting the Hudson River (an estuary) with the Harlem River (a strait). Prior to being modified by glaciation and subsequently by man, a true stream flowed here controlled by the existing lithology and structure. A fuller discussion will be presented.

Isham Park
The marble here and in this area is the type locality named after the village of Inwood. The marble is gray to buff-colored medium to coarse textured marble and dolomitic marble. Essentially the same lithology as the Inwood found at Stop 1. Graphite, pyrite, phlogopite, tremolite and diopside (malacolite) may be found here and elsewhere in the neighborhood. Quartzite, interbedded with the marble, indicates original sandy beds. These quartzite layers plus aplites often occur as disconnected boudins. An occasional thin schistose layer suggests original mud or limey mud sedimentation. Folding and plastic deformation are present. Possibly the only example of a residual soil in New York City is present at this stop.

STOP 4. DI RIENZO STONE QUARRY
Yonkers granite gneiss.
Please be careful in this quarry. Do not collect any specimens from the trimmed and stacked rocks. These are the finished products of this quarry and the labor of those who work here.
Merrill et al. (1902) states that the Yonkers is "technically a gneissoid granite." The rock is composed of quartz and microcline feldspar with lesser amounts of orthoclase. The feldspars are responsible for the striking pink-red color. Although not obvious, foliation caused by the presence of biotite, is present. The biotite occurs as clumps, which are usually discoidal but occasionally spindle shaped. When the latter phenomenon occurs a lineation is also present. The foliation here is at a high angle (vertical) and is normal to the close-spaced horizontal sheeting. Minor amounts of hornblende, apatite, and zircon are also found. A single amphibolite layer occurs in the quarry. The Yonkers is invariably associated with the Fordham and almost without exception occurs as central masses surrounded by the Fordham. Contacts between both are sharply defined and gradational.

STOP 5. FORDHAM GNEISS
Almost 1000 feet of Fordham is exposed on both sides of the highway. The Fordham here exhibits great variation and the lithologic divisions of this formation as advanced by Hall (1968a. 1968b) is appropriate.

Inwood marble - Manhattan schist contact
The service road follows the contact between the Inwood marble which underlies the valley to the west and the Manhattan schist which forms the ridge on the right (east). Exposures of the Manhattan can be seen periodically.

STOP 6. FORDHAM GNEISS
Three subdivisions of the Fordham were tentatively identified by Hall (1968a) at this site. The Fordham body occurs as a northward plunging anticline. Sprain Lake valley immediately to the east contains Inwood marble. Numerous exposures of the marble are found along the east side of the valley paralleling the parkway.

Manhattan schist in a north plunging anticline
The ridge Which we cross between Sprain Lake valley and NY 100 to the east is underlain by Manhattan schist which forms a north plunging anticline.

STOP 7. MANHATTAN SCHIST
Manhattan schist plus Amphibolite layer near contact with Inwood marble in valley of NY 100.
Continuous exposures of Manhattan schist on west side of road.

Exposure of Inwood marble on east side of road.

Core of Yonker granite occupying center of hill.

Continuous outcrop of Yonkers granite on crest of hill.

Fordham gneiss outcrops occupying side of hill.

STOP 8. HARRISON DIORITE
Merrill et al. (1902) lists quartz, hornblende. feldspar and biotite as the principal constituents in this unit. Feldspar includes orthoclase and plagioclase (oligoclase-andesine). An igneous origin is indicated for the unit. Merrill further suggests that the Ravenswood granodiorite found in Queens County to the south may be a correlative equivalent.

STOP 9. EASTERN UNDIFFERENTIATED SEQUENCE
Intersection of NY 125 South and US 1. Park in bank parking lot. Freshly exposed schist along rear of parking lot. The unit here is part of the larger area of undifferentiated schists and gneisses first mentioned at Mile 23.6 on the Cross-Bronx Expressway.

A2: STRUCTURE AND FORM OF THE TRIASSIC BASALTS IN NORTH CENTRAL NEW JERSEY
Michael Sichko Jr.
Nassau Community College
Introduction
The structure and form of the Triassic basalts in north central New Jersey is exposed in the First, Second, and Third Watchung Mountains, and the Palisades Sill. The First, Second, and Third Watchung Mountains are tholeiitic basalt flows that are topographically prominent ridges in northern New Jersey (Fig. 1). They strike N 40° E and have a gentle dip of approximately 17° NW. Their northeastern and southwestern sections exhibit curved terminations, thus giving the ridge system a synclinal trough appearance. They are also terminated in the northwest by a border fault that separates the Triassic basin from the Pre-Cambrian gneisses that lie to the northwest. The three extrusive sheets are interbedded with Triassic sedimentary rocks (shales, sandstones, and argillites) of the Newark Group. The extrusion of the successive lava flows took place at the time of deposition of the Newark Group (Lewis, 1908).
The Palisades Sill is emplaced in a structural and stratigraphic basin called a taphrogeosyncline by Kaye (1951). It has intruded the Newark Group and where it has concordant contacts the intrusion has a general strike of N 30 0 E., and dips between 10° and 15° NW (Walker, 1969). The Palisades Sill also has satellite intrusions above it, such as the small laccolith or sill at Granton Quarry. The Palisades Sill is probably in part concordant and in part discordant (Thompson, 1959, Lowe, 1959).
The Palisadian Igneous Province
The igneous rocks and their counterparts in the other Triassic basins record the emplacement of basic magma on an enormous scale, 1,000 miles in length and about 200 miles wide. Significantly they correlate broadly with the vast Karoo dolerites and equivalent basic rocks in the Southern Hemisphere, and like them, apparently were emplaced during an episode of tension attending the widening of the Atlantic basin (Van Houten, 1969).

A2: STRUCTURE AND FORM OF THE TRIASSIC BASALTS IN NORTH CENTRAL NEW JERSEY

STOP 1. Granton laccolith or sill
In this exposure a satellite intrusion from the Palisades Sill, the Granton sill or laccolith, can be observed. The Granton sill has intruded the Lockatong formation of the Newark Group. In the easterly section of this exposure small appendages of the sill exhibit intrusive contacts with the shales and sandstones of the Lockatong formation. At the contacts the chilled diabase has an intersertal - intergranular texture, away from the contacts the diabase has an intergranular texture. The whole outcrop dips to the west at a gentle 15° to 17°. Fossils have been found in the black shale layers , they include fish remains of coelacanths, Diplurus longicaudatus, Diplurus newarki and the common branchiopod Estheria ovata (Schuberth, 1968).

STOP 2. Basal contact of the Palisades Sill and the Mg-Olivine Layer.
Below the basal contact of the Palisades Sill a small stream has eroded through the Stockton formation which consists of arkosic sandstone and black and green shales. The alternating sandstone and shale beds attest to the changing environmental conditions during the deposition of the Stockton formation. Continuing up the trolley track right of way the concordant basal contact between the Palisades Sill and the arkosic sandstone of the Stockton formation can be observed. The contact metamorphic zone at this outcrop can be observed by noting that the shale has been metamorphosed into a hornfels and the sandstone has developed quartzitic characteristics. Columnar jointing has developed perpendicular to the basal contact at this outcrop. Further up the right of way a xenolith of shale plucked from the floor of the intrusion can be seen near the basal chilled zone. At the bend in the trolley route the Mg-Olivine layer comes into full view. The base of this layer is approximately 40 feet above the chilled diabase. The layer outcrops as a highly weathered zone due to differential weathering of the cliff face. It is believed that the Mg-Olivine layer formed at the junction between two magma phases (Walker, 1969). Columnar jointing is pronounced directly above this layer.

STOP 3. Upper contact of the Palisades Sill.
This exposure of the upper contact of the Palisades sill is concordant with the rocks of the Stockton formation (Fig. 4). The chilled diabase is fine-grained here as compared to the course-grained diabase to the east of this outcrop. Although the metamorphism is less pronounced at the upper contact than the lower contact the shale has been metamorphosed into a hornfels and the sandstone has developed quartzitic characteristics. Both the contact and strata dip gently to the west.

STOP 4: Pillow lava of 1st Watchung Lava.
The pillow lava of the 1st Watchung Mountain at this exposure represents the uppermost flow unit of a two unit system (Van Houten, 1969). Nichols (1936) defines a "flow unit" as a tongue shaped structure within a flow. The individual pillows are somewhat ellipsoidal in outline and have long dimensions of approximately 0.5 meters in length (Fig. 5). Adjacent pillows have adjusted their shape to fit together quite well. Some individual pillows exhibit vesicularity and radial jointing. The pillows lie in a matrix of tuffaceous material and weathered basalt. It appears that pillow lavas must generally form by a combination of the process of bulbous budding underwater and by the generation of an emulsion (Lewis, 1915; Fuller, 1940) in which the disperse phase consists of rounded "drops" of fluid lava and the disperse medium is water, very watery sediment, or water-saturated hyaloclastic debris. (MacDonald, 1967).

STOP 5A: Upper Surface of 1st Watchung Lava Flow
The Garret Mountain overlook allows for a spectacular view of the Triassic Lowlands of northern New Jersey. From this vantage point the more resistant Watchung lava flows are seen topographically as ridges. To the northeast beyond the Paterson water gap, which is occupied by the Passaic River, the 1st Watchung flow is easily observed. To the northwest the 2nd Watchung mountain can be seen. On the walkway at the overlook evidence for glacial movement in this area is in the form of glacial polish, striations and erratics. The hackly appearance of the unglaciated portions of the lava flow are due to the differential weathering of the tops of columns which comprise a major section of the lower flow unit of the 1st Watchung mountain.

STOP 5B: Lower Contact of the 1st Watchung Mountain.
At this exposure the lower chilled contact of the 1st Watchung mountain lies directly over the red shales and sandstones of the Brunswick formation. In this lower flow unit, the chilled zone is highly vesicular, above this zone the colonnade and entablature are clearly visible. In the talus slope below this outcrop representative samples of each zone of the basaltic lava flow can be found.

STOP 6: Lower part of the 1st Watchung mountain
In this exposure of the lower part of the 1st Watchung mountain one encounters a well-developed lower colonnade zone and a curvi-columnar zone with markedly radiating slender joints (Manspeizer, 1969).

A3: PLACER MINING AND MINERAL BENEFICIATION OF ILMENITE SAND DEPOSITS NEAR LAKEHURST, N.J.
Harold F. Roellig, Adelphi University
Dennis Radcliffe, Hofstra University
INTRODUCTION
Ilmenite (FeTiO3) is used mainly in the production of white titanium dioxide. Because of its whiteness, high refractive index and resulting light scattering ability, synthetic titanium dioxide is unequaled as a non-toxic white pigment for paints, paper, rubber, dyes and ceramics.
Ilmenite and rutile (TiO2) are used in the production of titanium metal. Titanium is one of the space age metals. One hundred years ago it was considered a vexing contaminant in magnetite deposits that often rendered the iron ore worthless. Today titanium is in demand as an alloy of aluminum to strengthen the skins of supersonic aircraft so that they can withstand the high temperatures generated by air friction. It is also used as a refractory alloy to withstand the intense heat of jet engines and rockets.
Titanium pigments were made originally by dissolving ilmenite in sulfuric acid, crystallizing to separate iron, then hydrolyzing the solution and calcining the precipitate. Newer plants utilize the Kroll process whereby titanium tetrachloride is produced in fluidized bed chlorinators. The tetrachloride is then either oxidized to the white dioxide pigment or is reacted with magnesium under an inert atmosphere to produce titanium metal.
Although titanium is the ninth most abundant element in the earth's crust, it seldom is found in concentrations rich enough to be used as an ore. Thus, natural concentration processes especially placer formation are required to form a significant ore body. The mining of ilmenite in New Jersey by Asarco, formerly the American Smelting and Refining Company, occurs in such placer deposits.
The ilmenite concentrates generated at this operation are sold under a 10 year contract to E.I. du Pont de Nemours and Co. for manufacture of pigments.
Ore reserves are approximately 15O million tons assaying 1.951 total included TiO2. The production rate is 185,000 tpy (tons per year) of ilmenite concentrates or about 20% of total U. S. production. At this mining rate ore reserves should last about 20 years.

ASARCO Manchester Plant
Turn into Asarco private road and drive South to the parking lot.
2013: The operation was expected to have a 20- to 22-year life from 1973 when production began, based on a planned initial rate of 155,000 tons and a possible ultimate rate of 185,000 tpy of ilmenite, averaging 63% TiO2. All ilmenite produced was under a sales contract to Du Pont. The mine was closed in March 1982 because of escalating costs and the prospect of long-term oversupply situation.
From: NRC Briefing with Manchester township, NJ to discuss Heritage Minerals, Inc., Lakehurst, NJ
Within this area, NRC licenses about 695 cubic yards of monazite-rich sands, because it is source material. Source material contains greater than .05% by weight of thorium and or uranium in any chemical or physical form. The physical form at heritage is monazite.
History of Facility
From 1971 until 1982 sands containing economically interesting components as well as small concentrations of uranium and thorium were dredged from about 50 to 70 feet below the site by ASARCO, the original owner.
Beginning in 1987, Heritage Minerals processed the stockpiled sands which were left behind as tailings from the previous mining operation. The sands were processed by physical means to separate the zircon and leucoxene (titanium oxide). In 1989, NRC found that heritage was producing a waste stream that met the definition of source material and directed heritage to apply for an NRC license. Heritage applied for the license and it was issued in January 1991.

A4: SHINNECOCK FLOOD TIDAL DELTA AND COASTAL STABILIZATION PROBLEMS WEST OF SHINNECOCK INLET
Larry McCormick
Department of Geology
Southampton College
INTRODUCTION
The shoreline along the south side of eastern Long Island changes regularly in character along an east-west traverse. From Montauk Point to Napeague Harbor it is characterized by cliffs up to 60 feet high overlooking narrow cobble beaches. A relatively short segment of the shore between Napeague Harbor and the village of East Hampton consists of a series of low dune ridges trending roughly parallel to the present water line. From East Hampton to Southampton Village is a sandy beach bordered landward by a single narrow dune ridge that rests on the truncated margin of a gently sloping outwash plain. Westward from Southampton the beach and dune ridge are separated from the rest of Long Island by a series of shallow bays. At one time this barrier island system was continuous to Fire Island Inlet, but is now interrupted by Shinnecock and Moriches Inlets.
Much of the shore zone from East Hampton westward is densely populated. The construction of numerous dwellings close to the water has caused much attention to be focused on the continual recession of the beaches in this area. This concern has resulted in periodic rather piecemeal beach nourishment programs as, well as construction of grain fields to trap sand from the prevailing westerly littoral drift. Shoreline recession results from both natural processes and from works of man. An understanding of the causes should be helpful in determining where beach stabilization programs are needed, and to some degree, guide the selection of the kind of remedial action necessary.
On this trip stops be visited along the segment of barrier island from Southampton to Moriches Inlet. The stops are designed to emphasize the nature of the problems facing this portion of the barrier island and the actions taken to solve these problems.

STOP 1.
STOP 1. is located at the intersection of Halsey Neck Lane and Meadow Lane in the Village of Southampton. This stop is most easily reached via Route 27A which intersects Halsey Neck Lane at the western margin of the Village of Southampton.
This portion of the shoreline has experienced rapid recession over the last four years, and is an interesting locality to examine the buried record of storm events.
The second house to the east is owned by Nelson Levings and was located immediately behind the partially destroyed bulkheading that now extends out onto the beach. The house was moved during the winter of 1971 to avoid destruction. This occurred only two years after the construction of the protective bulkheading. Slightly further east is the beach pavilion of Southampton Town, now perched at the edge of the dune line. To the west several large mansions are now-dangerously close to the front of the dune line.
During the fall of 1972 a rather unique protective device was installed in front of the large pinkish buff home located nearest the dune line to the west. A trench was excavated in the dune and plasticized bags of woven nylon were pumped full of beach sand. The filled bags were placed in the trench and stacked up to provide a riprap for the dune face. The dune was then reconstructed over the riprap to protect them from vandalism. At the time of this writing they are not exposed but might be visible by the time this field trip is taken.
Excavation of the beach at this point usually exposes thick layers (2-6 inches) of heavy minerals. These thick layers represent storm lag deposits and provide a handy reference of the beach profile under storm conditions. The location of the storm beach is of considerable importance when considering the depth to which bulkheading or riprap is to extend.
These layers are usually local, pinching out quickly along the strike of the beach, but when present are useful indicators of storm conditions.
Thin heavy mineral layers (less than 2 inches) are common and frequently represent a wind lag deposit generated on the beach berm. In Plate lB these berm layers have been truncated by a storm beach that has in its turn been buried by a wedge of light buff colored sand characteristic of rapid beach accretion.
Heavy mineral storm layers may be simple lenses rich in garnet and magnetite or they can exhibit the rather complicated scour and fill structure illustrated in Plate 2A and B. The latter are produced as a wave cut scarp which migrates up the beach face under storm conditions. Waves strike the scarp and scour out a shallow trough carrying off the lighter minerals and leaving behind a thin apron of heavy minerals. As the scarp and trough migrate up the beach the thin aprons of heavies coalesce to form the thick upper heavy mineral layer.
Layers of coarser sediment do not appear to be related to high energy conditions. Size seems to depend more on availability than energy on south shore beaches.

STOP 2. Flood tidal delta at Shinnecock Inlet.
The vehicles will proceed to the Marine Station at Southampton College where trip participants will board a boat for a trip to the tidal delta. The vehicles will then proceed to the west side of Shinnecock Inlet via Ponquogue bridge and wait for participants to return.
INTRODUCTORY STATEMENT
Prior to the first careful surveys of the Shinnecock area in 1838 an inlet existed about two miles east of the present location of Shinnecock Inlet. However, a map of the U. S. Coast and Geodetic Survey shows that it had closed by 1838. From Southampton west to Round Dune the barrier island was unbroken from 1838 until the hurricane of 1938.
During the storm of 1938 a wash-over channel developed and cut rapidly downward to produce a narrow channel that was ultimately deepened, widened and stabilized to form Shinnecock Inlet. Details of the change in the Inlet since 1939 are given in Figure 19 of Taney's publication "Geomorphology of the South Shore of Long Island." That figure is included here for the purpose of completeness. A small revetment was constructed on the west side of the Inlet in 1947, but it was not until 1952 that construction on the presently existing jetties was begun. Dredging of the channel before and after jetty construction has been carried on intermittently.
In 1938, when the Inlet was opened, some sand was carried inside the Inlet and deposited by the storm surge. Tidal currents sweeping in and out have added to that original sand mass and modified it to create the vast flood tidal delta that exists today. Similarly, sand being carried by the longshore currents was swept seaward to form a large asymmetric ebb tidal delta. The historical development of these deltas and the distribution of sediment on them is the subject of this stop.

STOP 3.
STOP 3 is reached by proceeding westward on dune road from Shinnecock Inlet. Travel 1.1 miles west of the Inlet and stop on the newly paved section of Dune Road.
This is the site of a major storm wash-over created during the storm of February 18. 1972. The actual wash-over channel has been dammed with two parallel mounds of artificial fill and the road, destroyed during that wash-over, has been repaved. A small wash-over fan extends to the north of the road. The dune ridge normally present along the barrier island is non-existent at this point.
This weakened segment of the barrier island provides an excellent setting to discuss the dynamic nature of the barrier island system on eastern Long Island and causes of that dynamism. All of the basic elements that make up the barrier system are present at this spot or are visible nearby. The beach face, berm, wash-over channel and wash-over fan are present and dune ridges are visible a short distance to the east and west.

STOP 4.
STOP 4 is located 11.0 miles west of Shinnecock Inlet on Dune Road. Any point along the road that allows access to the beach will satisfy the requirements for this stop.
The purpose of this stop is twofold: First to observe the solution that has been adopted to stem the problem of shoreline recession, and second, to allow participants an opportunity to contrast the condition of this protected segment of the barrier island with the unprotected portion downdrift of the last groin (STOP 85).
The groin field observed at this location was constructed under the authorization of the 1960 River and Harbor Act for the area from Fire Island Inlet to Montauk Point. The 1960 Act provided for the establishment of a continuous dune line to defend against flooding from storm surge and the establishment of sand bypass plants at Shinnecock and Moriches Inlets. In addition, provision was made for the construction of several groins and for a beach nourishment program. The federal government assumes the major share of the expense in construction of these groins in view of the broad protection that the hurricane protection portion of this program implies (approximately 70% federal funds). The level of federal funding is much reduced for erosion control (approximately 30% federal funds). The author is on public record as criticizing the 1960 plan for acting as an umbrella for local beachfront owners to obtain a high percentage of federal funding for what is essentially erosion control.
The piecemeal enactment of the 1960 plan which included groins almost as an afterthought, is brought about by the necessity for state and local authorization of funds prior to construction. At present none of the local governments have seen fit to provide the funding that would complete the broader aspects of the plan, and it is probably safe to assume public opinion will bar the complete enactment of the plan in the foreseeable future.
It is obvious that the structures protected by the present groins enjoy a more secure position on the barrier island than homes in unprotected areas. The abundance of shell material in the sediment of the dune ridge at this point is the result of being derived from dredged bay bottom, a practice often abhorrent to local baymen.

STOP 5. is located 13.9 miles west of Shinnecock Inlet on Dune Road immediately west of the last groin in the Westhampton Beach groin field. Here you will see evidence of recent wash-over, damage to local homes, and the absence of any substantial dune ridge. Of course all of this is directly attributable to the position of this beach with respect to the groin field. Starved for sand, it has receded at a very rapid rate.
Currently there is considerable pressure from homeowners and local government for the construction of six additional groins in this area in order to stabilize the beach to Moriches Inlet. The cost of this work will be approximately 10.5 million dollars and would be completed as part of the 1960 plan.
Consideration of how the natural system operates, the interference of man in this system, and interests of local property owners prompts a number of interesting questions.
Can local governmental units with sharp political boundaries deal intelligently with the management of natural systems that do not have the same boundaries?
Should federal projects of the type seen today be allowed to progress without any real assurance that funding will be provided to complete the project?
What will be the likely effect of the construction of six additional groins?
Can the public justify further coastal modifications on the basis of a realistic cost benefit ratio?
If the groin field were to be extended to Fire Island Inlet, would there be enough sand in the system to nourish the westernmost groin?
Does the public owe local homeowners west of the last groin for damages to their property?
To what extent is the damage produced by natural island migration and to what extent produced by the works of man?

A5: ENVIRONMENTAL GEOLOGY OF DEMOCRAT POINT, FIRE ISLAND, N.Y., AND THE JONES BEACH BARRIER ISLAND
ENVIRONMENTAL GEOLOGY OF DEMOCRAT POINT, FIRE ISLAND, N. Y., AND INFLUENCES ON ADJACENT BARRIER ISLANDS
Manfred P. (Fred) Wolff.
ENVIRONMENTAL GEOLOGY OF THE JONES BEACH BARRIER ISLAND
Coordinator:
Peter J. R. Buttner
Lecturers:
Richard A. Brady
Francis A. Hyland
Robert Johnson
Coastal marshes occur as a result of estuarine sedimentation and are now included as a class of distinct landforms. On the south shore of L. I. these marshes, originally well south of this area, are superimposed over the drowned lower coastal plain that extends seaward as the nearshore continental shelf. This region, including past and future sites of salt marsh development, is underlain by a layer of glacial outwash that has been modified into barrier beach-estuarine environments by the rising sea.
The estuary forms a partially enclosed body of water where mainland fresh-water and sea water meet to form a region of shallow brackish water with variable salinity, water temperature. and sediment load. The Great South Bay Estuary System is a 70 mile long "bar-built estuary" extending from Lawrence in Nassau County to Southampton in western Suffolk.

A5: ENVIRONMENTAL GEOLOGY OF DEMOCRAT POINT, FIRE ISLAND, N.Y., AND THE JONES BEACH BARRIER ISLAND
M.P. wolff, P.J.R. Buttner, R.A.Brady, F.A. Hyland, R. Johnson

STOP 1. -Robert Moses State Park
(Trucks will transport you along the beach for one mile to the jetty at Democrat Point. Walking time is about 35 minutes.)
INTRODUCTION
This area, located at the federal jetty on the western end of Fire Island (and Robert Moses State Park) has been mapped since 1825 when it was located at the tip of the Fire Island Lighthouse - 4.6 miles (7.4 km.) east of its present position. The growth rate now averages 212 feet (71 meters) per year (Figure 1).
The purpose of this stop is to view the effects of the accretionary processes of spit formation from littoral drift and wave refraction associated with a laterally migrating barrier island. A more detailed analysis of the features, processes, and history of this migration is presented in article B-3 of this guidebook.
Because of the necessity for beach nourishment and inlet stabilization, the area is now dredged once every 2-3 years and the accumulated sands transferred to an adjacent feeder beach (Cedar Island and Gilgo beaches) on the west side of Fire Island Inlet. It is unfortunate, that this trip follows shortly after such a period, when only a few features are present. However, participants are invited to return at other intervals during the next few years when all of the characteristic sediment features will again reappear. You are now seeing the initial growth stages of a new intertidal spit platform, but the development of the extensive primary and modified spits and their migration across embayments and lagoons will not reappear until the subtidal spit platform has been built seaward - as was the case once before (Wolff, 1972).
M.P. wolff, P.J.R. Buttner, R.A.Brady, F.A. Hyland, R. Johnson

STOP 2. Captree Beach State Park
Walk east across dunes to area of highest elevation. From this point one can see the end of the Jones-Captree Beach barrier island, remnants of an earlier extension of Fire Island (Sexton Island and the Fire Islands), and the position of the old and new inlets. All of this area was once exposed to the open ocean. The lighthouse on Fire Island indicates the western edge of that island and the wide inlet that was present over 140 years ago. The barrier beach west of the lighthouse and the now parallel inlet indicate the changes that have occurred since that time. (Wolff, Article A-5-AM.)
Captree Beach and its extensive back-barrier salt marsh (partially dredged for the state boat channel) is toe first area in western Great South Bay with this development, and this initiates the pattern that characterizes the remainder of the barrier island chain to Jamaica Bay. The extension and overlap of Fire Island has curtailed most erosion, though some modification by the ebb and flow of tidal currents continues. Note the bulkheads and the position of the dense scrub vegetation and trees on the dunes near the inlet. Though protected by Fire Island, it also receives no sediment from that source and some erosion continues to persist.
Cap tree is an important bird nesting area and, because of its proximity to the mainland and the inlet, an important area for bathing, boating, fishing and picnicking. Each morning a fleet of fishing vessels leave the boat basin for points within the bay, in the inlet, or in the ocean.
M.P. wolff, P.J.R. Buttner, R.A.Brady, F.A. Hyland, R. Johnson

STOP 3. Erosion of dunes near West Gilgo Beach.
It is normally dangerous and unlawful to stop here on the road during the summer and parking in the West Gilgo Beach Parking Lot is advisable -but for the sake of completeness there will be a "quick stop" at this point.
This area is characterized by previous beach and dune erosion to the extent that this process has almost reached the position of the Ocean Parkway. Many areas on the adjacent barrier islands - from Fire Island to Rockaway - exhibit similar effects. The sand bypassing from Fire Island Inlet7 coupled with the littoral drift, still assures the preservation of a broad, well-nourished beach at this point and indicates the positive effects of man-made intervention without the necessity of groins. However, the lack of natural sand supply for the more western barrier islands (especially the Rockaways) continues to impose a serious problem. Should attempts at stabilization continue or, considering the long-range effects, should "nature take its course?" These are questions that have important social, economic, and political as well as environmental consequences, and must be handled both on a local and on a regional basis.

STOP 4. Tobay Beach and Bird Sanctuary.
This area will illustrate the creation, development, and maturation of back-barrier tidal salt marshes.

STOP 5. Area for sewage outfall line
Area for sewage outfall line from Cedar Creek Sewage Treatment Plant.
In order to curtail estuarine pollution, a series of sewage outfall lines extending across the bay and beneath the barrier islands into the ocean have been proposed - this is one of the first to be completed (1973). While there is little that can be observed on the surface, the vegetation across the dredged zone (the pipe was 8 feet in diameter) clearly demonstrates the progressive succession of different barrier island species and the return of the native flora.

STOP 6. Parking Field #9 of Jones Beach State Park.
This area is similar to Stop 4. Note the position of the Parking Lot versus the line of the primary dunes and the successive zones of berm accretion. Originally intended to handle the overflow from neighboring Parking Lot 6, after at least two attempts to repair the area, the project has been abandoned. The collapse of the southern edge of the parking lot was due to undermining by lateral erosion. As with Stop 4, each of these areas of extensive erosion are near old inlets. (Wolff Article A5AM.)

STOP 7. Parking Field 5 and Administration Area.
The previous stops have emphasized some of the dynamic natural and man-made changes that are occurring on the barrier islands. Administrative personnel will review some of these processes and explain how the L.I. State Park Commission is trying to achieve a balance between the requirements of the natural environments and the importance of the maintenance and development of public recreational resources (Figure 1). Any man-made structure has a limited life expectancy, usually measured within 1-3 human generations. Coastal zone management with regard to public recreation cannot consider long-range (100-year) changes since the demand for recreational resources varies within 10-20 year intervals. By working within these intervals useful environmental and recreation resource management policies can be established and these can be modified to fit the long-term coastal changes.

STOP 8. West End of Jones Beach, Parking Lot 2.
As with Democrat Point (Stop 1) this area exhibits all the characteristic features of lateral and vertical sand accretion. The construction of the jetty in the 1950's now provides a very wide beach and a wide zone of dune development. Note in particular the type of vegetation associated with these recent dunes.

A6: GEOLOGICAL OCEANOGRAPHY OF A SEGMENT OF LONG ISLAND SOUND AND SEDIMENTARY DYNAMICS OF A COASTAL POND: FLAX POND, OLD FIELD, LONG ISLAND, N.Y.
GEOLOGICAL OCEANOGRAPHY OF A SEGMENT OF LONG ISLAND SOUND
J. R. Schubel
Marine Sciences Research Center
State University of New York at Stony Brook
Stony Brook, New York 11794
The field trip will be conducted aboard the Marine Sciences Research Center's new 55 foot research vessel, R/V ONRUST. The ONRUST, completed in 1974, was designed specifically for work in coastal and continental shelf waters. It is well equipped for work on biological, chemical, geological, and physical oceanographic problems of the coastal environment.
The primary objective of this cruise is to introduce the participants to some of the tools and techniques used by oceanographers in their quest to understand, interpret, and predict the processes that characterize the coastal marine environment. A secondary objective is to use some of these tools and techniques to make a cursory examination of several different sedimentary sub-environments of Long Island Sound. The shortness of the trip precludes a detailed look at any particular area and requires that the cruise be concentrated in the Sound off Port Jefferson Harbor. The actual ship track will be dictated largely by weather and sea state, and therefore no specifics are given in this brief report.
After a variety of methods and instruments have been demonstrated by MSRC staff members, participants will be encouraged to use the devices to collect their own samples, and to make their own measurements. The methods and instruments to be employed; the measurements to be made; and the samples to be collected, fall into several broad categories.
Each participant will be provided with a set of oceanographic data from Long Island Sound and a suggested reading list for possible classroom use in oceanography courses at the undergraduate and beginning graduate levels.
SEDIMENTARY DYNAMICS OF A COASTAL POND: FLAX POND, OLD FIELD, LONG ISLAND, N.Y.
Karl W. Flessa, Glenn A. Richard and Mary K. Cushman
Department of Earth and Space Sciences
Stony Brook, New York, 11794
Flax Pond is a small estuarine marsh located on the north shore of Long Island, New York (Fig. 1). Since 1966 the Flax Pond marsh has been owned by the State of New York and administered by the Department of Environmental Conservation and the Marine Sciences Center of the State University of New York. Under this administration the marsh has been utilized as a research site for studies dealing with salt marsh flora and fauna, estuarine hydrology, nutrient cycling and coastal sedimentation. The protected nature of the Flax Pond marsh and its similarity to other intertidal marshes in the northeast make it a unique scientific resource for the region. In addition to the advantages conferred by state protection, the Flax Pond marsh is situated in an area which was settled early in the history of New York. Historical records which mention Flax Pond date back well into the 18th century, maps showing the pond date from 1797, and accurate coastal charts of the region were first issued in 1852. Thus, the existence of historical records and maps provides an opportunity to study the development of man's interaction with this coastal pond and permits the documentation of the natural and manmade coastal changes of the past 200 years.
The objectives of our research on the sedimentary dynamics of the Flax Pond marsh include the understanding of the processes, rates and environmental controls of sedimentation and marsh growth. We have, to date, utilized information derived from historical records, maps and charts, the stratigraphy of the marsh sediments, and marker bed studies to arrive at estimates of the rates of marsh accretion. A summary of this work is presented in this paper and will be illustrated while in the field. Future projects will utilize radiometric techniques and suspended sediment budgets to arrive at additional estimates of the rates and environmental controls of marsh growth.

A6: GEOLOGICAL OCEANOGRAPHY OF A SEGMENT OF LONG ISLAND SOUND AND SEDIMENTARY DYNAMICS OF A COASTAL POND: FLAX POND, OLD FIELD, LONG ISLAND, N.Y.

The footbridge over the main channel provides an overview of the marsh and its geologic setting. The lighthouse to the ENE is situated atop Old Field Point, a bluff composed of the morainal sediments of the Harbor Hills moraine. The hills to the WNW, terminating in Crane Neck Point, are also composed of this glacial sediment. These bluffs are the source of the sediments on the barrier beach. Topographic, vegetation and surface sediment maps will be displayed on posters at this stop and will provide an opportunity for a description and discussion of the general features of the marsh. See also the section in the paper entitled "The Flax Pond marsh: general features".
Proceed to the northeast through a stand of Iva (the marsh elder) and Juncus (black grass), across a sandy patch which shows how the common marsh grasses spread via rhizomes, and onto a stand of Distichlis spicata and spartina patens. Note how sharply these vegetation zones are bounded. Continue SINGLE FILE (to minimize the damage to the marsh) across the Spartina alterniflora zone to the bank of a small tidal creek. The far bank exposes the stratigraphy of the marsh sediments.

Note the three distinct strata that are exposed here: the Spartina peat at the top, the reddish-brown, finely textured sedge peat, and the underlying coarse sand. Historical records indicate that the transition from sedge peat to Spartina peat took place in 1801. This datable horizon permits the calculation of sedimentation rates for the Spartina peat. Calculated estimates for vertical accretion range from 2.4 to 4.6 mm/yr. Lateral accretion proceeds at the rate of 158 m2/yr. At this site a poster which summarizes the historical information in Table 1 will supplement the discussion of the environmental significance of these strata. Additional background information for this stop is in the article sections entitled "Flax Pond: the historical record" and "Sedimentation rates determined from historical records". Proceed back along the trail toward the footbridge. Instead of crossing the bridge turn to the northwest and walk along the periphery of the wooded upland (probably a submerged kame) to Stop 3.

To the south and west of this stop are bare mudflats, hummocks of spartina alterniflora, mudflats newly colonized by S. alterniflora, and areas with well established stands of the grass. These areas include the sites of our marker bed studies. A poster showing monthly increments of sediment accretion since October, 1974 and cumulative accretion since that time will provide the basis for a discussion of the rates, environmental controls and seasonal patterns of marsh accretion. For additional information regarding this stop see the text section entitled "Sedimentation rates determined from marker bed studies".
Proceed to the east along the margin of the wooded area. We will pass through an extensive stand of Juncus and Iva. On the inner margin of the barrier beach you should note the lobate appearance of the gravel deposits. These lobes appear to be encroaching upon the marsh surface. Their movement is presumably due to extreme storm waves. The area immediately to the west of the inlet was dredged during the 1940's for sand and gravel. Present depths in this area are about 3 meters at low water.

The inlet, stabilized by jetties since 1947, has not been a stable feature of the Flax Pond marsh. Longshore drift and storms have been responsible for changes in the character and position of the inlet. The maps and charts also indicate a change in the dominant direction of longshore drift from westerly prior to 1947 to easterly since that time. A series of maps, charts and photographs dating from 1797 to 1969 will illustrate the major changes in the configuration of the inlet over the past 178 years. For further discussion see the section titled "Maps and charts".

A7: THE LATE QUATERNARY GEOLOGY OF THE MONTAUK PENINSULA: MONTAUK POINT TO SOUTHAMPTON, LONG ISLAND, N.Y.
William Nieter and Walter S. Newman
Department of Earth and Environmental Sciences
Queens College of the City University of New York
Flushing, New York 11367
Bronius Nemickas and Edward J. Koszalka
Hydrologists
U.S, Geological Survey
1505 Kellum Place
Mineola, New York 11501
ABSTRACT
The Montauk Peninsula is composed of several glacial, periglacial and interglacial units including the Gardiners Clay(?), Montauk Till Member of Manhasset Formation, late Wisconsin drift, and loess. The stratigraphy of these units is complicated by large-scale glacial tectonic structures. The occurrence of two or more drifts in several localities suggests that this area underwent multiple glaciations and that the morainal features may, in part, be diachronous. The surface of much of the late Wisconsin drift is mantled by aeolian sediments that closely resemble loess. Accumulation of the loess is believed to have occurred under true periglacial conditions which created thermokarst features such as the Scuttlehole depression.
Long Island is long and narrow, reaching east-northeastward from New York City to form a fishlike eastward extension of New York State. The island lies south of and is approximately parallel to the Connecticut shore and is separated from it by Long Island Sound. Long Island also forms a north shore of that ocean reentrant known as the "New York Bight".
Although part of the Atlantic Coastal Plain physiographic province, Long Island features a topography almost completely modified by glacial, proglacial, and periglacial processes. Two conspicuous terminal moraines extend almost continuously along the length of the island. The Harbor Hill Drift traverses the northern length of the island. The Ronkonkoma Drift traverses the central length and constitutes a major part of the south fork. The island abounds in other glacial and proglacial features, such as the coalescing outwash fans and aprons that form much of the southern part of the island.

A7: THE LATE QUATERNARY GEOLOGY OF THE MONTAUK PENINSULA: MONTAUK POINT TO SOUTHAMPTON, LONG ISLAND, N.Y.
W. Nieter, W.S. Newman, B. Nemickas, E.J. Koszalka

Enter Montauk Peninsula
Enter Montauk Peninsula and cross Shinnecock Canal connecting Great Peconic Bay (north) to Shinnecock Bay (south).
W. Nieter, W.S. Newman, B. Nemickas, E.J. Koszalka

Southampton College to your immediate right (south)
W. Nieter, W.S. Newman, B. Nemickas, E.J. Koszalka

Morainal knob and kettle topography of the Shinnecock Hills
From Southampton College to this point you are traveling through the rolling morainal knob and kettle topography of the Shinnecock Hills

Moraine bends to NE
Outcrop on north side of road showing head of outwash. The moraine at this point bends sharply to the northeast.

Southampton to south
Village of Southampton approximately 1 mile south
of the road.

Ronkonkoma Terminal Moraine
The trace of the Ronkonkoma Terminal Moraine can be seen to the north with the outwash plain abutting against it. The outwash is covered by thin loess in this area.

Entering head of Mecox Bay, Mill Creek on south.

Duck Farm
One of the numerous Long Island duck farms can be seen on immediate left on north shore of Hayground Cove which enters directly into Mecox Bay. There is considerable controversy concerning periodic eutrophication of the water mass caused by nitrogenous wastes from these farms entering the bay.

Scuttlehole depression
On north and south of road observe the southernmost extension of the Scuttlehole depression. Kellis Pond is to the south and occupies most of the depression. (See text and description of Stop 6 for details of origin.)

Village of Bridgehampton.

Sand and gravel pits
Active sand and gravel operation at north side of road. These pits have been dug deeply enough to intersect the water table, and present operations involve dredging methods.

Site of former wave cut cliff.

Leave glacial deposits
Leave glacial deposits and descend onto the Napeague beach complex. Note steep wave-cut bluff to immediate north. This is the central part of the Napeague tombolo. Napeague Harbor is to the north.

Observe wave-cut bluff in morainal deposits.

Observe dunes from north of the moraine.
Dunes have been blown inland and over the moraine for approximately 1 mile.

Ascend the moraine.
Road divides. Bear left and ascend the moraine. The western boundary of Hither Hills State Park is crossed here.

Rapid descent from moraine, entering Montauk Village.

Traveling on beach deposits
Traveling on beach deposits that have been drifted in by long-shore currents. Fort Pond to north has been isolated from the ocean by a double tombolo.

Reascend moraine.
Several overlooks on the road provide beautiful ocean views on clear days.

Oyster Pond can be seen in the distance to the northeast.

STOP 1. Montauk Air Force Station.
Here along the littoral bluffs on Long Island's southeast coast which includes the type section of the Montauk Till, we have the opportunity to examine the excruciating complexities of the island's Quaternary stratigraphy. The hoodoo topography developed on the Montauk Till provides a conspicuous marker bed which enables us to follow the till where it outcrops along the eroding bluff. However, the complicated glacial tectonics, immediately apparent in these exposures, has detached blocks of Montauk Till, and these blocks have been transported into anomalous stratigraphic positions. To our west, stratified drift beneath the Montauk Till is exposed in a large mile-wide antiform. Stratified drift including laminated silts and clay, frequently folded and in fault contact, also lie above the Montauk Till. The barely finite age obtained from a log in the lower portion of the upper stratified drift, has been previously noted while a second date on disseminated wood from the upper stratified drift dates at 12.170 ±180 years B.P. (QC-122 ). Discontinuous lenses of a younger till cap portions of the bluff. Also found in the upper part of the section are pockets of loess up to ten feet thick.

STOP 2. Ditch Plains.
The Montauk Till forms the base of the section exposed along the coastline. Close inspection of the till reveals pervasive deformation. The western end of our traverse displays well-developed hoodoo topography on the Montauk Till. The western portion of the section shows stratified drift and loess above the till. At the eastern end of the high bluff, thinly bedded fine sand dips towards the east and passes from view beneath the beach. This stratified deposit lies upon a persistent peat zone upon which rooted stumps are occasionally exposed. As noted previously, a radiocarbon date on one of these stumps shows it to be about 5500 years old. Excavation at the east end of our traverse (near where we enter upon the beach) discloses the following section:
Eolian sand
Peat
Laminated silt (lacustrine?)
Montauk Till
Since the peat appears to be mid-Holocene in age, the thinly bedded sand body appears to be the distal portion of a delta that was built into the Ditch Plains basin prior to the Holocene marine transgression of the area. We cannot explain why the late Holocene sand wedge was deposited. We suspect that it might have been deposited because the vegetation cover was temporarily destroyed allowing the mobilization of considerable amount of sand.

STOP 3. Montauk Sanitary landfill.
This section reveals at least 100 feet of stratified sand in the middle of the Ronkonkoma kame-moraine complex. The topographic maps of the area as well as air photos (figure 5) display a series of northeast striding ridges superimposed upon the moraine. These ridges appear to be push moraines. The deposit exhibits both folding and faulting, including several large thrust faults. The section is capped with a bouldery deposit that is probably till. The high percentage of boulders suggests the till has been washed and the boulders at least in part, represent a lag deposit. (Perhaps the term "flowtill" is appropriate here.)

Overlook on right side of road
Overlook on right side of road shows numerous beach and littoral features on north side of Montauk Peninsula. The Atlantic Ocean is to the immediate south.

Lunch Stop and Rest Rooms

A prominent wave cut bluff is directly to the north.

Magnificent dunes
Magnificent dunes can be seen on both sides of the highway. They are presently stabilized by vegetation.

Napeague Harbor can been seen on the right.
Beach ridges, dunes and lagoonal sediments typify this area.

STOP 4. Gravel pit at Amagansett.
Here is the last easternmost exposure of the Late Wisconsin drift to he seen before its termination at Bluff Road sea cliff and its reappearance 4 miles east-northeast at Hither Hills. The till at this stop has a sandier texture, fewer boulders, a lower clay content, and fewer glacial tectonic structures than the Montauk Till. The stratified drift underlying the till is postulated to be either an Early Wisconsin drift that was overridden and deformed by the Late Wisconsin advance or a Late Wisconsin proglacial outwash that was overridden by the advance. The lower stratified drift exhibits many glacial tectonic structures such as thrust faults and folds. This same unit also has preserved depositional structures such as cross bedding and graded bedding. A third unit of wind-blown sediments overlies the till.

STOP 5. Easthampton Bus Company
This stop is included to illustrate the late-glacial loess deposit and the surficial sands that have blown in and partially covered the loess in the Easthampton area. The flat bulldozed surface is near the top of the loess deposit. It is possible to dig down through some 62 inches of wind blown silt and enter coarse stratified sands and gravels below. The contact between the loess and the underlying glaciofluvial deposits is erosional and a lag gravel concentrate has been developed with many wind-abraded clasts and ventifacts which were left behind during a period of aeolian deflation. Frost action (cryoturbation), probably in late glacial times, disturbed much of the section and introduced the erratic pebbles into the loess from below. After deposition of the loess and some soil formation on the loess, dune sand was blown in from the south shore and heaped into 10-foot dunes in this area. The sands are now stabilized by a soil profile and by a mature forest cover. A minor paleosoil can be seen within the dune sands. The dune sands have stripped much of the A soil horizon from the top of the loess but the B horizon is still present here.
The dune sands are traceable on topographic maps and aerial photographs to the south shore and have blown inland at least 2.2 miles (3.5 km). The sequence of events determined from this and other similar outcrops in this area include: 1. deposition of the last glacial outwash sands and gravels 2. widespread aeolian deflation and the formation of lag-gravel concentrate and ventifacts 3. deposition of the loess on a cold barren surface devoid of vegetative cover and intense cryoturbation of the deposits. 4. indeterminate length of time during which a soil formed on top of the loess. 5. deposition of dune sand from the south shore, probably shortly after sea level reached near its present level. 6. stabilization of the dunes by soils and forest.

In this area, the outwash plain is blanketed with loess.
The trace of the Ronkonkoma Terminal Moraine can be seen directly ahead.

STOP 6. The Scuttlehole Depression.
The Scuttlehole depression is a large topographic feature some 2.5 miles (4 kilometers) in length. It is impossible to observe the entire structure from anyone point on the ground. Therefore, reference to a topographic map (Sag Harbor quadrangle) is recommended.
Our bus stop is on Scuttlehole Road just south of Shorts Pd. and just north of Haines Pd. To the north and south you can observe a topography that is strange for Long Island, reminiscent of karst topography. The elevation of the outwash plain (out of view from this point) on both sides of the depression is approximately 70 feet and the plain is amazingly level considering the nearness of the Ronkonkoma Terminal Moraine which is about 1 mile to the northeast. In this area, only glaciofluvial deposits and aeolian loess are known on the outwash plain. No till or ice-contact deposits or erratics are found on the outwash plain so the presence of glacial ice far south of the Ronkonkoma front is doubtful. The Scuttlehole depression heads near the moraine and extends southeast about 2.5 miles (4 kilometers) and consists of more than a dozen semi-isolated basins identical in size and shape with the two that can be observed here. The basins are steep-sided and flat-bottomed and are isolated from one another by shallow divides.
Several characteristics have led us to conclude that this feature is a collapse structure of thermokarst origin:
1. linearity of trend approximately 2.5 miles (4 kilometers) N25W.
2. beaded drainage system, an often observed phenomena in present-day periglacial areas.
3. size and shape of the individual basins are almost identical to present-day regions of active thermokarst.
4. lack of evidence for the existence of glacial ice in the area of the out-wash plain.
5. association with small scale periglacial features such as cryoturbated loess and a single ice wedge cast of the Scuttlehole depression.
Although not conclusive, we feel the evidence merits consideration and any discussion of the interpretation would be welcomed by the authors.

Outwash grades into kame and kettle topography
Note here how outwash abruptly grades into the kame and kettle topography of the moraine.

STOP 7. Southampton Sanitary Landfill Site.
At this stop one sees a contrast in morainal morphology between here and the previous sites. Here kame and kettle topography predominates as compared to the "push" topography seen earlier. At this site one sees mostly primary sedimentary structures, although secondary structures formed by glacial tectonic activity are present. Geophysical investigations have indicated a finer till-like material at a lower level of the pit, possible equivalent to the Late Wisconsin till.

A8: GEOTECHNICAL CONSIDERATIONS AT SHOREHAM NUCLEAR POWER STATION
Douglas S. Pierce and Peter K. Taylor
Stone &. Webster Engineering Corporation
Boston, Massachusetts
Long Island Lighting Company's Shoreham Nuclear Power Station is one of the largest engineering projects ever undertaken in eastern Long Island. It has required geotechnical considerations of a scope unique to nuclear-fueled electric generating facilities, and has been scrutinized closely by the general public and by various governmental regulatory agencies. This field trip will provide an opportunity to discuss the geotechnical investigations and decisions that are a part of nuclear power plant siting, design, licensing, and construction, and will include a tour of the facility itself, which is scheduled for completion in 1977.
GEOLOGIC SETTING
Shoreham Nuclear Power Station is located on the north shore of central Long Island, at the approximate landward edge of the Atlantic Coastal Plain (Figures 1 and 2). The crystalline rocks of the New England Piedmont slope gently seaward an estimated 1100 ft beneath the site. Overlying this deeply weathered remnant of the Fall Zone peneplain (Suter and others, 1949) is a thick sequence of unconsolidated coastal plain sediments of Upper Cretaceous to possibly Tertiary age. Long Island itself owes its existence to a somewhat linear accumulation of glacial debris unconformably overlying the coastal plain deposits. The island is separated from New England by a glacially over-deepened channel.
SITE VISIT
Due to the nature of this particular field excursion, a detailed road log will not be presented here. Instead, a lecture with slides will precede a walking tour of Shoreham Nuclear Power Station.

B1: LOWER PALEOZOIC METAMORPHIC STRATIGRAPHY AND STRUCTURE OF THE MAMARONECK AREA, NEW YORK
Thomas L. Pellegrini
SUNY at Buffalo
The rocks of southwestern Connecticut and southeastern New York can conveniently be divided into two northeast-southwest trending belts. The easterly strike belt is a metamorphosed eugeosynclinal assemblage of mixed clastic and volcanic rock (Hartland Formation and Harrisen Gneiss). The Mamaroneck area is located within this belt on Long Island Sound (figure 1). The strike belt to the west is a Cambrian-Ordovician quartzite-carbonate sequence (predominantly Lowerre Quartzite and Inwood Marble) deposited on a Precambrian basement complex of the Fordham and Yonker's Gneisses. Overlying this miogeosynclinal sequence are the syntectonic and overthrust members of the Manhattan Formation (Hall, 1968a). From the Berkshire Highlands to the Manhattan Prong. these two belts meet along a sharp discontinuity known informally as Cameron's line. Cameron's line is interpreted by many (Clarke, 1958; Gates and Christensen, 1965) as a thrust fault. Locally. in the Manhattan Prong, however. subsequent deformations may have obscured any local discontinuity.

B1: LOWER PALEOZOIC METAMORPHIC STRATIGRAPHY AND STRUCTURE OF THE MAMARONECK AREA, NEW YORK

The Granitic Gneiss outcrops on the west side of the road.

Axial region of the later stage fold
After entering the Mamaroneck Quadrangle, continue down Larchmont Avenue through the axial region of the later stage fold.

STOP 1. Larchmont Manor Park.
NO HAMMERING PLEASE! Enter the park along the paved path at the intersection of Prospect and Park Avenues. Proceed southeast (left) towards a small shelter on a promontory on Long Island Sound. The rocks here have been assigned to an amphibolite unit of the Schist and Granulite Member of the Hartland Formation. As the path continues before the clubhouse, it crosses a broad fold in interbedded schists and granulites which formed during the later stage of folding.
Generally, however, the minor folds related to this episode of folding are tight isoclinal folds. The parallel lithologic layering seen throughout this member is believed to be primary in origin. Although metasomatism may have accentuated this layering in the original S0 plane, these gross compositional differences are considered bedding, reflecting a sedimentary or volcanic origin. The early stage of isoclinal folding produced a foliation (S1) generally parallel to the S0. The later stage of folding refolded this early foliation. The S2 foliation produced clearly cross-cuts the S1 here.
Continue down the path towards the shelter past a glacially grooved and striated amphibolite. The numerous interbedded amphibolites to the east of the shelter occupy a persistent stratigraphic position and are believed to be of volcanic origin. Similar rocks have been described at Pelham Bay to the south (Seyfert and Leveson, 1968). Greenish calc-silicate lenses composed primarily of epidote and diopside with calcite are common here and often prominent in the crestal regions of folds. The numerous northerly plunging folds are related to the later stage of deformation. The variation in the angle and direction of plunge of the L2 axes may be due to an additional deformation, or it may be the reflection of the development of L2 on a curvilinear surface. Crosscutting, undeformed pegmatites can be seen throughout the park. These pegmatites probably correspond to the Acadian thermal event.
Across the inlet northeast of the shelter, the interbedded schists and granulites are typical of the rocks of the Schist and Granulite Member although to the north schist may be more abundant. The rhythmic interlayering of these rocks may represent graded bedding.

Outcrops on the west side of the road
The outcrops on the west side of the road near the playing fields behind the Administrative Offices of the Mamaroneck School District contain amphibolites very similar to those seen at STOP 1. Here, however, they are apparently a small isolated lens.

Contact of the Granitic Gneiss and the Schist and Granulite Member.
After crossing the bridge over the railroad tracks, turn left (west) onto Calvert Street across the contact of the Granitic Gneiss and the Schist and Granulite Member.

STOP 2. Pettijohn Park.
These outcrops of Granitic Gneiss lie near the center of this sill-like pluton. Typically this rock is a brown or brownish tan weathering, light bluish gray, fine to medium-grained, biotite-muscovite-quartz-feldspar gneiss. Microcline is the dominant feldspar; garnet is rare and occurs as small scattered grains. Biotite, although relatively sparse, gives the rock a distinct foliation which here trends northeast in accord with the major structures. The more typical fine-to-medium-grained gneiss at this exposure is commonly associated elsewhere with a white, foliated and lineated pegmatite. Although the contacts between the two types of rock tend to be sharp, the lineations and foliations pass without interruption into the more typical granitic gneiss. The pegmatites are therefore mapped as part of this unit.
Smaller bodies of this rock have been mapped throughout this area and the larger ones have been indicated on figure 1. Some crosscutting dikes have been observed within the Harrison Gneiss, however, the other bodies are all concordant. Although the smaller bodies tend to have sharp contacts, a zone of migmatite occurs along the contacts of this large body.

Contact of the Granitic Gneiss with the Schist and Granulite Member
Proceed down Crystal Street across the west contact of the Granitic Gneiss with the Schist and Granulite Member.

STOP 3. Veteran's Memorial Park.
Scattered throughout the park are excellent exposures of the Garnet Gneiss Member of the Harrison Gneiss. These exposures are on the west limb of the later-stage antiform. This member apparently pinches out further north and is not present on the east limb of the same fold (figure 1). The flat glaciated outcrops within and around the parking area expose a distinctly porphyroblastic zone within this member. The rock is more granitic than most of this member and the porphyroblasts are microcline commonly exhibiting Carlsbad twinning. This zone parallels the contact of this member with the Schist and Granulite Member of the Hartland Formation for at least two miles and appears as a distinct unit or units within the Garnet Gneiss Member. Intensely deformed metasedimentary layers are also present in these outcrops.
From the restrooms at the southern end of the parking area, proceed southwest (bearing 250°) across the recently filled valley to a dirt road and then up the east valley wall. PROCEED WITH CAUTION OVER THE CONSTRUCTION DEBRIS FILL! Total distance to the top of the ridge from the restrooms is about one thousand feet. These exposures contain some of the evidence for the volcanic origin of the Harrison Gneiss. The contact of both members of the Harrison Gneiss with the Schist and Granulite Member is always conformably interlayered with that member. As shown here, thin distinct metasedimentary layers, often only an inch or two thick, can be traced for tens of feet without interruption through the Harrison Gneiss. This interbedded contact can be up to 150 feet thick. The interlayering is suggestive of alternating sedimentary and possibly pyroclastic deposition rather than an intrusive or tectonic mechanism. The Prospect Gneiss, a possible western Connecticut correlative, has a similar contact. Crowley (1968, p. 39) believes that the Prospect Gneiss is a metamorphosed volcanic sequence. The Ravenswood Gneiss to the south also has an interbedded contact although Blank (1973, p. 656) considers it to be sedimentary.
Additional exposures of the contact, although quite deformed, can be seen west of the playing fields adjacent to the entrance to the park. The Schist and Granulite Member is exposed in the stream flowing by the nearby Louis M. Klein Middle School. As can be easily seen at this stop, topographic differences usually facilitate the location of the contact.

Recross contact
Recross the contact of the Schist and Granulite Member with the Garnet Gneiss Member.

Axial plane and contact
Cross the axial plane of the early stage fold and the contact of the Garnet Gneiss Member of the Harrison Gneiss with the Quartz Feldspar Gneiss Member. Here the two members of the Harrison Gneiss have been folded against each other (figures 1 and 2).

Quartz Feldspar Gneiss Member
The outcrops in front of the Harrison High School are of the Quartz Feldspar Gneiss Member.

Contact of the Harrison Gneiss with the Schist and Granulite Member
After crossing the west contact of the Harrison Gneiss with the Schist and Granulite Member, turn left (south) onto Mamaroneck Avenue.

STOP 4. Parking lot cuts off Mamaroneck Avenue.
NO CLIMBING ON THE ROCKS PLEASE! These extensive cuts are in the Quartz Feldspar Gneiss Member of the Harrison Gneiss. Large irregularly shaped segregations of quartz and feldspar and the lack of megascopic garnet easily distinguish this member from the Garnet Gneiss Member. Although biotite commonly exceeds hornblende in both members, the great abundance of biotite here accounts for their somewhat slabby appearance. Present throughout both members and evident in these outcrops are small lenses or streaks of fine-grained hornblende, biotite and feldspar usually measuring a few inches by a foot or more. Similar lenses have been interpreted as relict volcanic bombs in the Prospect Gneiss (Crowley, 1968, p. 39) and in the high grade metavolcanics of the Southern Appalachians (Tobisch and Glover, 1971, p. 2212). At the north end of these cuts and along Union Avenue, the contact with the Schist and Granulite Member is exposed. Here the Hartland Formation, on the limb of a small fold (figure 1), contains rusty weathering, sulphidic looking schists. The contact of this member of the Harrison Gneiss with the continuous but folded contact of the Schist and Granulite Member is also interbedded.
Most of the exposures across the Mamaroneck River in the northern part of Saxon Woods Park are of the Quartz Feldspar Gneiss Member. To the southwest, near the Hutchinson River Parkway, the Garnet Gneiss Member is exposed. There it apparently wraps around the nose of the refolded early stage fold (figures 1 and 2) but pinches out before reaching this location.

Recross the folded contact
Recross the folded contact of the Quartz Feldspar Gneiss and Garnet Gneiss Members.

Garnet Gneiss Member
Enter the southbound entrance ramp of the New England Thruway (I-95) passing exposures of the Garnet Gneiss Member and return to the Throgs Neck Bridge.

B2: GEOLOGICAL ASPECTS OF STATEN ISLAND, N.Y
A. Ohan, A. Kureshy and E. Kaarsberg
Staten Island Community College of the City University of New York
The purpose of this Staten Island field trip is to illustrate some of the major aspects of the island's geology. As shown in Figure 1, the geology of this area can be subdivided into four main units as follows :
1. A lower Paleozoic serpentine body that is exposed in the north central part of the island and which displays a northeast-southwest trend.
2. The late Triassic aged Stockton Formation of the Newark Group which overlays the serpentinite unconformably on the northwest. Its beds dip to the northwest and are generally arkosic in character. The southern extension of the Palisades diabasic sill is intrusive into the Stockton Formation.
3. The late Cretaceous aged Raritan Formation. which overlays the Triassic aged unit unconformably, is part of the Coastal Plain sedimentary deposits that outcrop on the southern and eastern part of Staten Island. It dips gently to the southeast and lithologically is composed of sand and clay interbeds.
4. Pleistocene deposits unconformably overlaying the older units almost everywhere on the island.

B2: GEOLOGICAL ASPECTS OF STATEN ISLAND, N.Y

STOP 1. Serpentinite Outcrop
This outcrop represents the largest continuous exposure of the Central Zone Serpentinite on Staten Island. The rock is a foliated serpentinized peridotite. The dominant mineral is antigorite which has replaced in varying degrees the original olivine and enstatite. The minor constituents are magnetite, brucite, picotite (chrome spinel), picrolite (sheared antigorite) and graphite. Numerous veins are filled with talc, chrysotile or carbonates. Note:
1. The foliation has been deformed into small folds displaying axial planes which are almost vertical and trending in a general northeast-southwest direction.
2. A number of folds are cut by an axial plane oriented slip cleavage.
3. Several small, high angle, northeast-southwest trending faults and associated fault zones.

STOP 2. Serpentinite Outcrop
(This outcrop is in the locality for a housing development and may be eliminated in the near future. If this occurs an alternative exposure will be visited.)
This exposure is located within the Border Zone of the Serpentinite body and is in close proximity to the near vertical Spring Street Fault. The rock is essentially fine grained, foliated and extensively sheared. The principal mineral is antigorite with small amounts of magnetite and brucite. Some porphyritic serpentinite is present with phenocrysts of olivine and magnetite in a matrix of antigorite. Talc, hydromagnesite, aragonite and artinite exist in veins or along shear planes. Note:
1. Topographic expression of the northeast-southwest trending Spring Street Fault Zone.
2. Small folds with axial planes oriented in a northeast-southwest direction.
3. Fault breccia with fragments of serpentinite and Triassic sedimentary rocks.
4. Near-source glacial erratics with fragments of serpentinite, Triassic sedimentary rocks and gneisses (possibly fanglomerates?).
2013: No outcrops appear to be present

Road follows contact of Serpentinite body
This road follows the almost vertical contact of the Serpentinite body and outcrops of this rock can be seen on the right in many places.

Hummocky terrain with poorly developed drainage
Open areas here begin to show hummocky terrain with poorly developed drainage so typical of glaciated areas to the north.

STOP 3. Terminal Moraine Glacial Deposit
Along the beach at the south end of Hylan Boulevard a Wisconsin aged terminal moraine has been clearly exposed by beach erosion. It shows the typical unsorted nature of this kind of glacial deposit with large boulders intermingled with finer rock debris. On the beach itself these boulders are left stranded after wave action and near-shore currents have removed the finer material. The great variety of composition that these boulders show bespeaks the great variety and far flung distribution of their source areas. For example the dark diabase boulders probably came from the Palisades Sill structure only a few miles to the north whereas many sedimentary boulders found on Staten Island often contain marine fossils which indicate that they probably came from rock exposures in east-central New York or northwest New Jersey.
In places further along the beach remnants of stratified glacial outwash deposits may be found.

STOP 4. Raritan Formation Outcrop
The outcrops in the quarries in this area represent largest continuous exposures of Cretaceous sedimentary deposits found on Staten Island. Two members of the Raritan Formation belonging to the Gray consolidated clays and the Red consolidated clays are represented at these exposures. The Gray colored clay deposits are characterized by the presence of lignite fragments and pyrite. The Red colored clays apparently do not contain any of these materials. These deposits are also characterized by various sedimentary structures of which cross stratification in the sands is one.
Samples of these deposits were processed for the study of any microfossil fauna, but none were recorded. Neither were any plant fossil remains found.

B3: NATURAL AND MAN-MADE EROSIONAL AND DEPOSITIONAL FEATURES ASSOCIATED WITH THE STABILIZATION OF MIGRATING BARRIER ISLANDS, FIRE ISLAND INLET, N.Y. AND A MAJOR BEACH EROSIONAL CYCLE AT ROBERT MOSES STATE PARK, FIRE ISLAND
NATURAL AND MAN-MADE EROSIONAL AND DEPOSITIONAL FEATURES ASSOCIATED WITH THE STABILIZATION OF MIGRATING BARRIER ISLANDS, FIRE ISLAND INLET, NY
Manfred P. (Fred) Wolff
A MAJOR BEACH EROSIONAL CYCLE AT ROBERT MOSES STATE PARK, FIRE ISLAND, NY
Imre v.Baumgaertner
Columbia University, Department of Geology, N.Y.
Fairleigh Dickinson University, Rutherford, N.J.
A major beach erosional cycle at Robert Moses state park, Fire Island, NY, during the storm of 1-2 December 1974: The confirmation of "Grazing-Swash Undercutting" as a major beach erosional mechanism.
At the present time the beaches around the world's coastlines, in general, are undergoing erosion (Tanner and Stapor, 1972). This applies not only to beaches "stabilized" by man, but also to areas where man's influence has not as yet disturbed the natural dynamic balance of the coastal zone. Where man has interfered directly with the natural movement of littoral drift by "improving" the shoreline or where large areas of the coastal plain have been altered for the sake of human progress, beach erosion has been more pronounced.
The quasi-universal problem of beach erosion may result from or is complicated by the many parameters that determine beach and shore dynamics, but the basic cause is the shortage of sand on and around the beaches.
Our problem at the present is further burdened by the fact that the "state of the art" in beach-erosion research has not as yet progressed to such perfection. We are unable to predict the kind of processes and the magnitude of transport on or off the beach for a set of approximate energy-input parameters, and we are far from describing the expected short- or long-term geomorphic changes.
Progress has been slow mainly, because hydraulic engineers (who alone possess the large and expensive apparatus needed for controlled experiments) are less interested in discovering the underlying principles of nature than finding an approximate empirical formula of limited scope. "None of the many empirical theories have either been confirmed or rejected by critical experiments designed to test the various arbitrary assumptions made" (Bagnold, 1968, p. 45).
In this report an explanation is offered for one of the hitherto-unexplained problems in beach-erosion studies - namely the origin of berm scarps, vertical scarps up to 2 m or more in height encountered in the berm and sometimes in the primary dunes. Scarps of various magnitude have often been described in passing (Thompson, 1937, Rosalsky, 1944. Ruzyla. 1972 among others). They have often been encountered by the author along the southern shore of Long Island - but no satisfactory explanation for their origin has ever been postulated.
The clue to the origin of these scarps was documented about 4 years ago when a scarp formation was observed and first recorded in detail by the author while in this area. Additional data resulted from the clear definition of events and the identification of the causes associated with the formation of these berm scarps. Finally, the storm of 1-2 December 1974 demonstrated the close-to-maximum erosional capability of this process in detail.
The following section describes the general wave and wind regime for the Fire Island area. Details of the weather pattern before and during the storm are also documented. A description of the subsequent loss of sand from the beach during the storm is followed by a brief explanation as to the nature of the erosional mechanism. The process of erosion, initially called "swash undercutting" (Baumgaertner, 1973) has been changed to "grazing swash undercutting" (Sanders and Baumgaertner, 1975) because of its sporadic nature on the beach foreshore.

B3: NATURAL AND MAN-MADE EROSIONAL AND DEPOSITIONAL FEATURES ASSOCIATED WITH THE STABILIZATION OF MIGRATING BARRIER ISLANDS, FIRE ISLAND INLET, N.Y. AND A MAJOR BEACH EROSIONAL CYCLE AT ROBERT MOSES STATE PARK, FIRE ISLAND

STOP 1. Gilgo Beach
This area has been designated as one of the western feeder beaches used to disperse sands dredged and pumped from Democrat Point and Fire Island Inlet by the Army Corps of Engineers. Located on a barrier island between Jones Beach and Fire Island Inlet (Figure 1) it has undergone numerous natural and man-made changes during the past 150 years principally related to sand migration by longshore drift and a rising sea. Numerous inlets were present some years ago, but all of them have since been closed by the construction of the Ocean Parkway and the littoral drift.
The purpose of this stop is to view the erosional and depositional features of a feeder beach. With a horizontal shoreward rate of erosion of 3 feet (1 meter)/year during the past 15 years (Everets, 1973), nearly 10 million cubic yards of sand have been artificially added to the beaches between here and Fire Island Inlet since 1959. The beach now has its nearly maximum seaward and vertical extent because of recently completed sand bypassing operations terminated in April. 1975. The oceanographic information for this area is in article A-5 of this guidebook. Additional data and reference sources for this area are in the study by Everets.

STOP 2. Democrat Point
This area, known locally as Democrat Point, has been mapped by the U.S. Coast and Geodetic Survey since 1834, and has been recognized as a classic area of rapid, complex spit growth adjacent to a man-modified parallel inlet (Shepard and Wanless, 1971). During the period of 1834-1940 it has grown westward 4.6 miles (7.4 km.) from the Fire Island Lighthouse to the federal jetty at an average rate of 229 feet (76 m.)/year (see Figure 9).
The purpose of this stop is to view the complex spits and other sediment features, to explain their origin and migration patterns, provide some data on flow conditions and grain size parameters, and to examine the surface and subsurface sediment features.
Because of the present necessity for sediment bypassing across Fire Island Inlet to the western feeder beaches at Cedar Island and Gilgo (as noted at Stop 1) the area is dredged periodically. It is unfortunate that this trip follows after such a period -the last dredging operation ceased in April, 1975 and only remnants of the intertidal spit platform are currently preserved. However, participants are invited to return at other intervals during the next few years when some of the features described for this stop will again be more evident. A single trip to Democrat Point and Robert Moses State Park has always been more meaningful if it is followed by another excursion within a few months to note the rapid changes.

STOP 3. Beach foreshore and berm
Beach foreshore and berm at Robert Moses State Park (Figure 1). Since the trip to Democrat Point is timed to coincide with low-tide, grazing swash undercutting, even if operating, cannot be observed. A trench across the berm will be examined to reveal details of the very recent history of the beach.

B4: JAMAICA BAY: A CASE STUDY OF GEO-ENVIRONMENTAL STRESS
Steven Englebright
Department of Earth and Space Sciences
State University of New York at Stony Brook
Stony Brook, New York, 11794
Jamaica Bay is the westernmost of the estuarine marshes which lie behind a system of barrier beaches along the south shore of Long Island (Figure 1). Horseshoe shaped, the bay is encircled by a gently sloping glacial outwash plain along its northern perimeter and by the elongate Rockaway barrier beach to the south. Human activities have fundamentally changed the surface character of the region and disrupted the natural geologic processes. The purpose of this paper is to examine the historic relationship between the natural geological environment and human activities.

B4: JAMAICA BAY: A CASE STUDY OF GEO-ENVIRONMENTAL STRESS

STOP 1. Early boundary of the Bay
This street corner is approximately on the boundary of what was, at the turn of the century, the shore of Jamaica Bay. Stretching out before you to the south was one of the great salt marshes of the northeast. Its 16,000 acres were penetrated by shallow meandering channels bordered by smooth chord grass, Spartina alterniflora. A broad belt of high marsh, the outer edge of which was approximately where we stand, was covered by Spartina patens. Notice that today you cannot even see the bay from here. The urban development that is apparent everywhere in this vicinity is typical of almost all of the former upland margins of Jamaica Bay.

STOP 2. The building on your left is the South Shore Incinerator.
In 1960 there were 2.5 million people living in New York within 5 miles of Jamaica Bay. The solid waste this large population produces is a serious disposal problem. By burning solid refuse, its volume can be reduced by as much as 90% and make its ultimate disposal considerably more efficient. As urban growth took place around the bay, solid refuse was used as landfill. This plant is built on filled marshland.
The South Shore Incinerator receives solid wastes from western Queens and most of Brooklyn. Collection trucks dump material into a waiting bin until it can be placed directly into one of four furnaces. The refuse is its own fuel unless it has rained, in which case oil is sometimes added to keep the furnace hot. The standard temperature is 1500-1600°F and the plant is kept operative 24 hours per day, Monday through Saturday. (On Sunday the furnaces are cleaned which explains the quiet, inactive atmosphere here today.) After incineration the residue is carted to a landfill. Before boarding the bus again, examine some of the ash (refuse) where it is piled outside the south end of the plant. After burial in a sanitary landfill these ashes will cause groundwater percolating through the fill to become highly acidic. Because of leaching, sanitary landfill sites, especially those immediately adjacent to the bay, can be expected to be a continuous pollution source.

STOP 3. Fountain Ave Landfill
As New York City grew around Jamaica Bay, it used the bay waters for disposal of liquid waste and the fringing marshlands for the disposal of solid waste. We are at the Fountain Avenue landfill. Some six thousand tons of solid refuse are brought here each day. There are two kinds of solid waste disposal sites: 1) a sanitary landfill consists of refuse which is sprayed with a germicide and periodically covered with a sand or earth cover; and 2) a garbage dump, which is simply an open disposal site. Before 1933 the City dumped most of its solid waste into the ocean, but it was forced to stop this practice after a Supreme Court ruling specifically prohibited it. Partly as a result of this, the deposit of solid wastes around the periphery of the bay increased in the 1930's just as sewage treatment programs were getting under way. Between 1938 and 1971, 10 million cubic yards of sand was dredged from the bay for sanitary landfills along the north shore of Jamaica Bay. In 1965, Brooklyn and Queens each produced 1.7 million tons of solid waste of which 947,000 tons were deposited in Queens, much of it on the Jamaica Bay marshes. This 300 acre landfill was begun in November of 1961. It is scheduled to operate until 1985 at which time it will become a park.

STOP 4. Beach Restoration
Walk up the stairs and go to the ocean side of the boardwalk. Sand trapped in artificially maintained inlets further west has been denied to the Rockaway barrier beach and portions of it have become so severely sand starved as to require artificial beach nourishment. By 1974 the berm in this area was completely gone, erosion of the boardwalk was occurring, and in places the shore parkway was threatened. The wide beach we see today is the result of a current ten million dollar beach restoration project begun in April and administered by the Army Corps of Engineers. By the time this project, the first of three between Jones and Rockaway inlets, is completed in November, 4,950,000 cubic yards of sand will have been placed along the shore between 110th and 45th Streets. The sand is obtained by dredging from a huge accumulation known as the "East Bank" some two miles off of Breezy Point. There it is loaded onto barges which transport it to a "booster" dredge-pump on the bay side of Rockaway Beach. Mixed with water it is then pumped under pressure through steel pipes across the barrier to the ocean side. Sand placement is progressing, steplike fashion in an updrift, i.e., easterly direction. By early September, under the influence of the prevailing westerly drift the area was acting as a feeder for the beaches further west.

STOP 5. Jamaica Bay Wildlife Preserve
We are in a National Park. Please read and obey the posted rules and regulations. Despite its natural look, this too is a man-made environment. Dikes around the two fresh ponds have been landscaped with abundant varied vegetation to attract wildfowl. Besides being a major nesting area, the Jamaica Bay Wildlife Preserve lies on the Atlantic Flyway. Over 300 species of birds have been seen here.
However, our main purpose in stopping here is to collect, not objects, but rather ideas, concepts, and impressions. This is a place of contrasts. Evidences of both positive and negative human interactions with nature are apparent everywhere; on the horizon and under your feet.
The guide for this part of the trip is yourself. Be sure to "synchronize watches" with everyone else before leaving the bus. Your challenge is to discover, observe, and reflect upon what you have seen today, as well as what you are about to explore. Stay on the trails and be sure to return by the appointed time.

B5: WISCONSINAN GLACIAL STRATIGRAPHY AND STRUCTURE OF NORTHWESTERN LONG ISLAND
Les Sirkin
Adelphi University
Herb Mills
Museum Supervisor
Nassau County Department of Parks
The most detailed report on the geology of Long Island is that of Fuller (1914). In this work, Fuller developed a detailed stratigraphy which incorporated the Pleistocene sediments of Long Island into the classical stratigraphy of 4 glacials and interglacials recognized in the midwest. Fuller's work, built on such preceding studies as Woodworth (1901) and others, contains many excellent stratigraphic sections, but it is restricted to the "state of the art" for that time. More recent contributions such as Fleming (1935), MacClintock and Richards (1936), deLaguna and Perlmutter (1949), Swarzinski (1963), Donner (1964), and Sirkin (1967, 1968, 1971, 1972, and 1975, and Sirkin and Stuckenrath, 1975) began to revise the stratigraphic interpretations, mainly in limiting the number of glaciations to mappable drift sheets. With the aid of palynology and radiometric dating, recent authors have been able to place the rock units into a more refined time scale.
Pollen analysis has shown that at least two cold episodes, corresponding to glacials, and possibly three warm intervals, an interglacial (?), and interstadial, and the postglacial, have taken place here (Sirkin, 1967, 1971, 1968, 1972, and 1975, and Sirkin and Stuckenrath, 1975). Additional information about glacial deformation has provided a better understanding of the complications observed in the stratigraphy (Mills and Wells, 1974). The recent discovery of interstadial deposits has also brought about a change in the interpretation of the stratigraphy of only a few years ago in which the trend seemed to be toward monoglaciation (Sirkin, 1968, and Connally and Sirkin, 1973). Prior to this discovery much of the confusion was centered around the incorporation of morainal terminology with stratigraphic units. This fostered a sort of morphostratigraphy in which drifts were named and associated with moraines. The observation that the moraines were constructed of superposed drifts (Sirkin, 1968) and the introduction of the new data (Sirkin, 1975, and Sirkin and Stuckenrath, 1975) has made it possible to distinguish between geomorphology and stratigraphy.

B5: WISCONSINAN GLACIAL STRATIGRAPHY AND STRUCTURE OF NORTHWESTERN LONG ISLAND

STOP 1A. Remanent area, known as Billy Goat Hill (Fig.3A).
2013: Google Earth imagery from 1994 shows some active mining, but much of the area was already being reclaimed. All locations of the stops are guesses.
This location has an apparently undisturbed 2 till - 2 outwash sequence (outwash-till-outwash-till). There is a 5-6 m layer of tan gravelly sand at the base of the cliff, which rests on clayey Cretaceous sands not far below the surface. A compact gray-brown till of fairly uniform thickness (about 2m) overlies the outwash. Abundant cobble and small boulder sized erratics can be seen in this till, and at one point a prominent boulder lag occurs at the top of the till. If this lower outwash and till are attributed to the early Wisconsinan glaciation, the till would be the Montauk Till equivalent on western Long Island. Above this till is another thick (8-10 m) outwash similar to the lower outwash, except with more prominent oxidization zones due probably to groundwater movement. A second till, well cemented and of variable thickness (2-4 m) overlies the upper outwash. The upper outwash and till represent late-Wisconsinan drift commonly observed in western Long Island.
In both cycles outwash and lodgement till were deposited. The lag boulder zone on the Montauk (?) Till may represent a mid-Wisconsinan erosion interval. Large boulders resting on the Roslyn Till (Sirkin, 1971) and numerous kames and minor kame-like moraines on the Necks north of the Harbor Hill terminal moraine are products of late Wisconsinan deglaciation.
It might be noted that Fuller (1914) placed the top of his Manhasset Formation (of Illinoian age in his time scale) above the upper outwash (his Hempstead Gravel). As will be seen at later stops, an angular unconformity often occurs at this horizon due to late-Wisconsinan deformation. No significant depositional hiatus can be justified between the upper till and outwash.
Proceeding to Stop 1B notice the persistent thickness and elevation of Montauk (?) Till. The late-Wisconsinan drift has been largely removed at several points by the sand mining. Other features of note are the well formed and sorted talus cones, mud cracks, and quicksand (BEWARE) if conditions are right.

STOP 1B. 1/4 mile west of Stop 1A (Fig. 3B).
The Montauk(?) Till is dramatically thicker at this location due to ice-shove deformation associated with the late Wisconsinan advance. A light reddish iron stain marks a folded thrust plane indicating that the relatively thin, undisturbed lower till of Stop 1A has been increased in thickness due to folding, faulting and probable flow. Dramatic changes in the thickness and position of the Montauk(?) Till have been described by Mills and Wells (1974) and can be seen at Stop 2 of this trip.
The thick till at Stop 1B is well cemented, contains many cobble and boulder-sized erratics, and exhibits the sharp ridge and pinnacle "hoodoos" also seen in the Montauk Till at Montauk Point. A till fabric in this till revealed a northeasterly source direction. When traced along the outcrop to the west, this till again thins and assumes an apparently undisturbed horizontal altitude. Above the disturbed section of Montauk (?) Till, there is an unusually thin deposit of late-Wisconsinan drift capped by about 2 meters of loess. A gravelly zone in the Roslyn Till may indicate a local flow till or outwash. To the west, the upper outwash thickens and the section looks much as it does at Stop 1A. Across the landfill site, a lighter area in the cliffs marks the site of an ice transported clay lens of probably mid-Wisconsinan age. This localized deformation is typical of the glacial stratigraphy north of the terminal moraine.

STOP 2A. North end of sand pits (Fig. 3C).
This section described by Sirkin (1968) and redefined by Mills and Wells (1974) exhibits several meters of gravelly outwash at the base, a large thrust block of ice-shoved Cretaceous sands, clays and gravels, and unusually thick, bouldery layer of Roslyn till. The Cretaceous thrust block, one of several (Fig. 4), is about 15 meters thick with a gravelly zone of rotted quartz pebbles near the top. The basal thrust plane is marked by a thin purplish clay and occasional small folds. There is also a less obvious thrust plane within the Cretaceous which is noticed by an offset in the gravel zone. The brown silt that covers the cliffs just south of Stop 2-A is sediment from an old settling pond that was placed on the cliff to slow the erosion.

STOP 2B. about 500 meters south of 2-A (Fig. 30).
A prominent erosion pinnacle of thick Montauk (?) Till with ice-shoved Cretaceous draped over the top is the highlight of this stop. The till dips steeply and pinches out less than 100 m to the north. To the south, it dips below thick talus and reappears at a lower elevation in the bluffs. The till then enters a large, almost 50 m high fold, swelling in thickness in the synclines and pinching out over the crest of the anticline (Fig. 4). Rising at a steep angle on the south limb of the fold, the till is truncated by the flat lying Roslyn Till at the surface.
The Cretaceous thrust block draped over the till pinnacle thickens rapidly just to the south and then tapers to a long wedge and pinches out above the large fold. The northerly, butt end of another Cretaceous thrust block is in contact with the steeply rising Montauk (?) till on the south limb of the fold. Thick, deformed outwash units (early-Wisconsinan below and late-Wisconsinan above theMontauk (?) Till) complete the deposits seen in this section, except that presumably in place Cretaceous beds are exposed in the lower elevations of the mining pits.
Other features of note in this vicinity include: a spectacular boulder field with erratics collected from source areas as far away as the southern Adirondacks, numerous Cretaceous iron-oxide and pyrite concretions, a deformed Cretaceous clay and lignite, containing pollen of Raritan age (Sirkin, 1974a); many crystalline quartz ventifact cobbles located on the Cretaceous surface suggesting strong periglacial winds (Mills and Wells, 1974); and a cobble filled stream channel cut into the Cretaceous thrust block beneath the Roslyn Till, just to the left of the Montauk (?) Till pinnacle.

STOP 3. Mid point on west wall
Approximate mid-point of the sand pits, along the west wall, northwest of STOP 1.
The section of peat, clay and oyster reef stacked in the late Wisconsinan drift has provided important new information on the late Pleistocene stratigraphy of Long Island. The dark layers in the cliff (Fig. 3E) are peat and clay layers. The structure of the section is similar to those already observed to the north. The beds have been recumbently folded and somewhat thrusted. The axes of the folds are nearly horizontal, and the peat and clay beds are often over thickened (doubled) or telescoped into greater thicknesses. The two main shell bearing horizons on the north side of the section represent the same unit with the underlying sequence overturned. Both have been folded into small synclines and are over thickened along the axes of the fold. They consist mainly of peat, marine clay, oyster reef, and thin interbedded till and outwash. A series of over 20 radiocarbon ages have been determined by Bob Stuckenrath of the Smithsonian Radiation Biology Laboratory. The dates represent a sampling of all of the units and of different materials from each layer including peat,shell and wood. The ages range from > 43,800 to 23,000 years B.P. and with the pollen data have made it possible to reconstruct the sequence of environments and vegetation during the mid-Wisconsinan interstadial and high stand of the sea. The brown peats lower in the section represent fresh and salt marsh deposits formed over 35,000 years ago in the western end of what is now Long Island Sound. These peats contain pollen of pine, spruce, birch, alder and non-arboreal pollen (NAP). These pollen spectra suggest boreal vegetation, like the northern needle leaf forest or taiga in northern Canada, and cold climatic conditions at the end of the early Wisconsinan glaciation. The shell beds, dated around 31,000 years B.P., contain pollen of pine, hickory, black gum, oak, birch, and minor hemlock and NAP. This assemblage indicates a much warmer climatic regime and a regional forest composed of pine, oak, and hickory. The black gum suggests a coastal setting. These sediments also contain foraminifera similar to those of the Sound today. Overall, the climate and vegetation are similar to the modern climate and vegetation in this area. Evidence of cooling is seen in the pollen from the peats and clays dated at 28,150 years B.P., found above the shell zones. These sediments contain pine, alder, birch, hemlock, oak, and NAP; the indicators of warm temperate conditions have dropped out of the record or are only minor elements. Within the next few hundred years rather cold climate developed in this region as seen in the pollen record. Pollen of pine, birch, spruce, and alder suggest a return to boreal forests and cold, moist conditions by 27,900 years B.P. This evidence heralds the onset of the late Wisconsinan glaciation. The last radiocarbon date in this sequence, an age of about 23,000 on spruce wood may be the maximum age for the arrival of the late Wisconsinan glacier on Long Island, and for the deformation of the interstadial and subsequent deposits.

STOP 4. Northerly facing bluffs at south end of pits (Fig. 3F).
Although only 1 mile south of Stop 1, the section here appears markedly different. Instead of the two distinct tills of Billy Goat Hill, the Montauk (?) Till is represented by a series of thin tills interbedded with thin layers of orange , oxidized outwash. The Roslyn Till at the surface is much less pronounced here and in places may be absent completely. Fuller (1914) noted lateral changes in the Montauk (?) Till, and Mills and Wells (1974) found an orange outwash phase of this till at the north end of the sand pits. Facing the main section of slopes and looking eastward, the Montauk (?) shows a facies change from the thin interbedded till and outwash to a single thicker till with outwash above and below. Since this outcrop is located at the foot of the proximal slope of the Harbor Hill terminal moraine, we may be observing lateral facies changes associated with glacial deposition.
At the low outcrop near West Shore Road, a thin bedded deposit probably of lacustrine origin covers the Montauk (?) Till. The late-Wisconsinan drift is very thin with no till, and the section is capped with loess.

STOP 5. About 100 m northwest of the stairway.
STOP 1. About 100 m northwest of the stairway.
The cliff section reveals a sequence of outwash, till, outwash, and loess. At the base, from the level of the beach upward are approximately 5 m of glacial outwash composed of stratified sand and gravel. A compact, brown till (a sandy loam with abundant cobbles and boulders) about 1 m thick overlies the outwash. Above the till another unit of stratified sand and gravel (outwash?) forms a lens pinching out to the southeast and thickening to about 2 m to the northwest. The height of the cliff diminishes southward as this unit pinches out. The section is capped by about 1 m of loess. On the beach there is an abundance of cobbles and boulders. Diabase and purple-red puddingstone conglomerate erratics, along with till fabrics and other rock compositions suggest a northwesterly source area for the till. The diabase may be derived from the Palisades and the puddingstone from lower or middle Paleozoic conglomerates such as the Green Pond Conglomerate found near the New York-New Jersey border northwest of the Palisades.

STOP 6. At the actively slumped section in the topographic high in the bluffs.
The increased elevation of the bluffs is due to the thickening to about 8 m of the fine grained bedded sediments above the till. These stratified layers exhibit small scale cross bedding and bedding rippled by translational waves overturned to the southeast. This unit is characterized by clay, silt, and fine sand at the base which is somewhat obscured by slumping. It coarsens upward into fine and medium sized sand. Overall this unit probably represents sedimentation in a proglacial lake that formed between the ice just to the north and the upland to the south. Eastward across the bay in Eatons Neck, a well defined, horizontal band is visible in the bluffs. This dark layer also consists of proglacial lake sediment that overlies Cretaceous sand, but at a somewhat higher elevation than the lake beds at Lloyd Neck. The proglacial lake deposits are seen as evidence of the "Necks" stillstand during the recession of the late Wisconsinan glacier. A marked increase in cobbles in the loess layer and a thin stone layer on the stratified sands also appears in this section. Between Stops 2 and 3 the elevation of the bluffs decreases and the lake sequence becomes thinner. Also, the dark silty base of the lake deposits becomes visible and minor deformational features begin to appear in the overlying sediments. The surface unit has coarsened and also shows evidence of deformation, mainly small thrusts displaced southward. At one point a sizable granitic boulder in this unit has been rotated to the southeast. This evidence suggests southeastward movement of ice that overrode and deformed this section. On the beach a number of predominantly dark colored erratics of mafic composition have been eroded from the till. Some of these rocks resemble the Harrison Gneiss found to the north and northwest in southern Westchester and Connecticut.

Stop 7.
This stop is separated into two parts, 7A and 7B. Stop 7A (Fig. 5B) is in the low cliff where well exposed lake silts may be observed. Here the basal unit of interbedded, fine grained silts and sands are well exposed. These beds are somewhat disturbed and have small folds that are overturned to the southeast, and represent additional evidence of minor glacial deformation due to overriding by the ice.
STOP 7B is just to the northwest of Stop 7A.
The lake beds pinch out between these stops and the coarsened cobble unit rests directly on the compact (lodgment?) till. The rapidly changing nature of the upper unit is apparently the result of changing levels of energy of nearby ice and meltwater from the ice. It may have been emplaced as a till or ground moraine or as a head of outwash. Alternatively, this layer could be a colluvium or a lag deposit developed after the ice receded. Thus this unit seems to exhibit a combination of glacial, glacio-fluvial, or postglacial erosional characteristics. Clearly, deposition occurred near the glacial margin and some glacial overriding is indicated in the minor deformational features. When the ice stood along the northern edge of Lloyd Neck, tongues of ice may have extended southward into Huntington Bay. Till was deposited at the ice front, and outwash, colluvium and lacustrine sediments accumulated on the upland south of the ice and in and around proglacial lakes. Minor fluctuations of the ice resulted in the minor deformational features and in the sorting of the gravel layer.

STOP 8. The low cliff at the northern point of the beach.
The till-like character of the upper unit is more apparent in this section where it rests directly on the lower till. Pronounced thrusts and complex folds or convolutions occur along the contact between the beds. The more felsic nature of the erratics seen on the beach is in marked contrast to the rocks on the beach to the south.
This upper till is of limited extent and seems to grade southward into proglacial deposits. It was probably deposited during the "Necks" stillstand, with a different source area than the underlying till. While correlation with other local tills has not been resolved, the lower till at Lloyd Neck may be the equivalent of the upper or late Wisconsinan till (the Roslyn Till) in Port Washington. The differing source areas between the two (possible) late Wisconsinan tills may be due to their interlobate position and the stacking of Hudson Valley and Connecticut lobe deposits as the ice front fluctuated.
The following sequence of events is postulated for deglaciation in this region.
1. Late Wisconsinan ice downwasted, thinned and gradually receded northward from the terminal moraine.
2. As the ice receded minor lineations of surficial deposits and meltwater channels developed, marking ice marginal positions.
3. When the ice reached the northern margin of the necks, a major stillstand occurred. Meltwater cut east-west drainage channels such as Lloyd Harbor.
4. Ice tongues expanded into and excavated U-shaped valleys where the bays are today. Kames on the proximal slope of the Harbor Hill moraine mark the southward extent of this re-advance.
5. As the ice receded, proglacial sediments, outwash and colluvium were deposited. Lacustrine sediments accumulated in proglacial lakes dammed between the ice and the upland. Minor fluctuation of the ice deformed these sediments but on a much smaller scale than the deformation observed at Port Washington which was related to the main advance of the Late Wisconsinan glacier.
6. Recession of the ice from the "Necks" position formed other minor lineations observed in the position of small islands of glacial deposits in the Sound and minor moraines in Westchester and Connecticut.