121 pages · Run: Sunday, 25 September 1988; Sunday, 17 September 1989

Objectives

1. To understand the general geologic relationships of Long Island and the occurrence of ground water in various geologic units.
2. To be duly impressed by the evidence for the rapid westward growth of the west end of Fire Island as a result of inlet migration (average rate of 1 meter per week in the interval 1834-1940).
3. To become familiar with the composition of the beach sediment (including at least three populations of particles: a. well-sorted white medium sand; b. well-sorted dark-colored, esp. dark reddish, medium sand; and c. poorly sorted coarse brown sand, gravel, and shell debris.
4. To recognize the various parts of an ocean beach, including the shore-parallel ridges of sand (are they dunes?), berm, beach face (and/or beach scarp), and the three morphodynamic zones of an ocean beach: supratidal, intertidal, and subtidal.
5. To study the relationship between deposition of new layers of sediment and sediment surfaces, including both small-scale bed forms and large-scale depositional "slopes;" and to recognize plane, parallel strata and cross strata.
6. To understand how distinctive sequences of strata are formed by shifting of depositional slopes and the significance of prograding parallel to shore and of prograding normal to shore.
7. To understand the dynamic effects of processes such as waves and tides at modern sea level and to consider the long-term history of sea-level changes, as related both to movements of the lithosphere and to world-wide (eustatic) effects, particularly with respect to climate.
8. To realize how the effects of the operation of the geologic cycle through time create a geologic record of sediments and of sedimentary bedrock.

113 pages · Run: Saturday, 22 October 1988; Sunday, 28 October 1990; Saturday, 21 May 1994

Objectives

1. To get to our third "new" van rental garage before they go out of business.
2. To enjoy the spectacular scenery of the southern Hudson Valley, New York, during its finest viewing season.
3. To examine the geologic evidence which proves that the mafic- and ultramafic rocks, including cumulates, of the Cortlandt Complex, are parts of a pluton intruded into the continental crust as magma and later cooled in place, and were not thrust upon it (as are ophiolitic sequences from the deep-sea floor).
4. To study the contact between the Inwood Marble and the stratigraphically overlying pelitic unit (lower schist of CM's revisions of the geology of the Manhattan schist, and/or Annsville Phyllite) and the contact metamorphic effects on both within the contact metamorphic aureole of the Cortlandt plutons and in xenoliths within the pluton.
5. To examine the effects on the bedrock surface of glaciers that flowed across the region at different times and from different directions, with particular emphasis on the crescentic marks made on the Proterozoic granitoid rocks of Bear Mountain.
6. To compare the composition of the clasts from near the base of the Newark Supergroup with the composition of bedrock now exposed nearby.

Field stops (6)

1. 1 - Igneous flow layering in norite, Pluton V of Cortlandt Complex. [UTM Coordinates: 588.94E / 4568.78N, Peekskill quadrangle.] Situated at the western edge of the Central Funnel of Balk (1927), we here examine northeast-dipping coarse- to medium-grained norite with an igneous flow lamination composed of plagioclase laths (reddish tint) and hypersthene (an orthopyroxene).
2. 2 - Glaciated Inwood Marble and Manhattan Schist? [UTM Coordinates: 587.29E / 4567.44N, Peekskill quadrangle.] Low outcrop on the north side of 11th Street of dolomitic- and calcitic Cambro-Ordovician marble exhibiting glacial grooves and scratches. On the south side of the street occurs marble plus phyllite also showing glacial striae and grooves. We think it's the Annsville Phyllite.
3. 3 - Glaciated Manhattan-Inwood contact and the Cortlandt Complex, Franklin Delano Roosevelt Veterans Hospital. [UTM Coordinates: Traverse from 589.55E / 4565.1N to 589.1E / 4565.1N, Haverstraw quadrangle.] Four areas of interest are here covered in a traverse. The traverse starts with a rounded knoll has been sculpted by glacial ice coming from two directions. We then examine the Sauk/Tippecanoe unconformity at the edge of the Hudson River, contact metamorphic effects in the Manhattan Schist (Unit Om), and the pegmatitic Cortlandt diorite.
4. 4 - Poikilitic, flow-layered Cortlandt norite (Pluton V) with spectacular xenolith of contact-metamorphosed Inwood Marble. [UTM Coordinates: 589.65E / 4570.3N, Peekskill quadrangle.] Orthopyroxene-bearing gabbro (norite) of Pluton V of the Cortlandt Complex here exhibits poikiloblasts of primary igneous kaersutitic amphibole ranging from 1-4 cm and averaging 2 cm in size. Within the norite occurs an elongate xenolith of tightly folded, contact metamorphosed Inwood (Wappinger equivalent) Marble.
5. 5 - Perkins Observatory, crest of Bear Mountain: Proterozoic granitic gneiss with crescentic glacial gouges. [UTM Coordinates: 583.15E / 4573.5N, Popolopen Lake quadrangle.] Here, we examine glacial grooves and crescentic gouges on rounded knolls of Proterozoic gneiss that have been sculpted by glaciers that flowed across the Hudson Highlands. The usual two directions are indicated: from NNE to SSW and from NW to SE.
6. 6 - Stony Point Battlefield and west edge of Cortlandt intrusives (Optional). [UTM Coordinates: 585.62E / 4565.8N, Haverstraw quadrangle.] At this stop we make three small traverses at Stony Point State Park; one south of along the railroad cut to see conglomerate of the Newark Basin, one along the railroad cut that exposes intrusive rocks of the Stony Point-Cortlandt Complex and, a walk through the famous Stony Point battleground.

141 pages · Run: Sunday, 20 November 1988; Sunday, 21 April 1991

Objectives

1. To study the effects of extreme folding, faulting, and metamorphism of the Lower Paleozoic strata of New York City.
2. To examine lithologic variations in the three schist units of New York City formerly "lumped" together into the Manhattan Formation.
3. To examine the evidence for Cameron's Line and the St. Nicholas thrust.
4. To get up close and personal with mylonitic rocks.
5. To examine the effects of multiple glaciations.
6. To get in the groove, glacial-, that is!
7. To find sufficient restrooms to keep field trip participants happy, and,
8. To try to visit all of our planned stops (Fat Chance!)

Field stops (7)

1. 1 - Hartland exposures near West 90th to 91st streets [UTM Coordinates: 586.22E / 4516.00N, Central Park quadrangle] and between West 82nd to 85th streets [UTM Coordinates: 585.95E / 4515.50N, Central Park quadrangle], Riverside Park, Manhattan. The Hartland Formation or upper schist unit (C-Oh) crops out in Riverside Park from West 116th Street southward to West 75th Street. Exposures near West 90-91st Streets and from West 82-85 Streets are examined for metamorphic and glacial features.
2. 2 - Middle schist unit (C-Om) exposed at West 165th Street, Manhattan. [UTM Coordinates: 588.78E / 4521.44N, Central Park quadrangle.] The middle schist unit (C-Om), is here exposed in a large outcrop west of Riverside Drive. We describe the structural and metamorphic geology of the rusty- to gray-weathering, coarse,biotite-muscovite-plagioclase-quartz-kyanite-sillimanite-garnet-tourmaline gneiss and schist with 2-15 cm interlayers of quartz-biotite-garnet-kyanite-sillimanite granofels. Several types of glacial features are also found here.
3. 3 - Inwood Marble and Inwood-Manhattan contact, Isham and Inwood Hill Parks, Inwood section of Manhattan. [UTM Coordinates: 590.97E / 4524.72N, Central Park quadrangle and 590.66E / 4525.40N, Yonkers quadrangle, respectively.] A few areas are examined in the traverse including facies of the Inwood Marble (C-Oi; originally called the Inwood Limestone by Merrill l890) in Isham Park. In entering Inwood Hill Park , the first prominent ridge is composed of kyanite gneiss and schist of the middle schist unit (C-Om). From there we examine a south-plunging F3 antiform which exposes tan weathering, gray-white Inwood Marble. The contact between the middle and lower schist units (the St. Nicholas thrust) is exposed in a 20 m zone from beneath the Henry Hudson Bridge abutment to river level. Directly beneath the bridge, where a dirt trail leads down to the river, a coarse-grained gray-white calcite marble with differentially eroded calc-silicate nodules is exposed at low tide. It is unknown whether the marble exposed at the low-tide mark is an interlayer in the lower schist unit (Om) or the Inwood Marble.
4. 4 - St. Nicholas Park, west of St. Nicholas Avenue between West 129th and West 141st Streets. [UTM Coordinates centered on: 588.58E / 4518.74N, Central Park quadrangle.] The St. Nicholas thrust here separates the middle schist unit from the Inwood Marble along the east edge of St. Nicholas Park. Excellent outcrops of the schist form the steep ridge of the park. The Inwood Marble is not exposed but, based on drill core data, underlies the lowland immediately east of the park.
5. 5 - Mount Morris Park at West 122nd Street and Fifth Avenue. [UTM Coordinates centered on: 589.15E / 4517.28N, Central Park quadrangle.] Another traverse stop to examine the mylonitic contact of the middle schist unit (C-Om) from the Inwood Marble (C-Oi) and overlying lower schist unit (Om).
6. 6 - Grand Concourse and the Cross Bronx Expressway, The Bronx. [UTM Coordinates: 591.70E / 4521.95N, Central Park quadrangle.] An excellent exposure of the lower schist unit (Om) occurs west of the Grand Concourse in an overpass above the Cross Bronx Expressway (I-95). Massive Inwood Marble occurs in the roadcut forming the south wall of I-95 beneath the overpass. This locality, together with exposures described earlier in Inwood Hill Park (STOP 3) are interpreted as the autochthonous essentially in place) portions of the Manhattan Schist.
7. 7 - St. Nicholas thrust and Cameron's Line, Cross Bronx Expressway, The Bronx. [UTM Coordinates: 592.94E / 4521.75N, Central Park quadrangle.] Most of the Paleozoic rock units of the NYC area converge in and around Boro Hall and Crotona Parks in The Bronx according to our previous and ongoing research efforts. In these small parks, separated by I-95, marble, calc-schist, granofels, gneiss, and mica schist are all exposed from west to east in NE-striking, imbricated ductile-fault bounded tectonostratigraphic units.

152 pages · Run: Saturday, 15 April 1989; Sunday, 29 September 1991; Sunday, 16 October 1994

Objectives

1. To study the four major units that are in contact on Staten Island (from the top downward, Layer VII, Quaternary sediments; Layer VI, Coastal-plain strata; Layer V, Newark strata; and IIAE, Paleozoic deep-water metamorphosed strata, and included Staten Island serpentinite). We will start with the oldest unit and study progressively younger units.
2. To examine the serpentinite of Todt Hill in light of W. O. Crosby's (1914) idea that the serpentinite body which we see now has resulted from two notable modifications to the original rock, or protolith. As a second topic, we shall consider the possible age and origin of the associated breccia that contains clasts of both serpentinite (and relatated talc "schist") and red siltstones from the Newark Supergroup.
3. To examine the petrologic relationships in the Palisades intrusive sheet; to see the effects of high-temperature reaction between the mafic magma of the sill and a xenolith of Lockatong Argillite of the Newark Supergroup, which forms the country rock into which the "city rock" of the Palisades was intruded. The argillite that became engulfed in the mafic magma was not only heated, it actually was melted and the small bit of felsic magma that formed did not mix into the mafic magma, but cooled to form a felsic igneous rock unlike that formed by solidification of the mafic magma. We shall also study the morphologic relationships of the sill and discuss our new model designating Staten Island as a potential magma feeder for the Palisades intrusive sheet.
4. To see what happens to a beach when its supply of sand is cut off.
5. To study Pleistocene sediments (tills and outwash); soil-forming reactions; mineralogic immaturity; provenance of erratics; sedimentary characteristics of braided-stream deposits; state of decomposition/preservation of stones as basis for relative ages of units; hematite-cemented sandstones and /or conglomerates.
6. To find out the current status of the continuous interaction between the beach whose predominant direction of longshore transport is toward the SW and the mouth of a small stream.
7. To examine a stratigraphic succession (possibly not needing to be converted by us into an SSF) in which a much-decayed immature Quaternary braided-stream outwash deposit rests unconformably on mineralogically mature Upper Cretaceous sands and clays.
8. To examine the contrasting kinds of strata in the coastal-plain Cretaceous, notably the effects of marine transgression whereby open-shelf sediments came to overlie sediments deposited on an intertidal flat.

Field stops (4)

1. 3 - Great Kills (Oakwood Beach) Park - Modern beach rapidly advancing landward by marine erosion. [UTM Coordinates: 574.15E / 4488.30N, The Narrows quadrangle.] The Oakwood Beach is undergoing rapid erosion that has intensified during the last 14 years. In 1989, the year of our first trip to this area, the main bathhouse and building that is the office for the Park Police were in great jeopardy. A scarp, 2 to 3 meters high, had formed by the undercutting action at water level. This edge is an active slope subject to collapse and is marked by a snow/sand fence. Only a few years ago, the water's edge was 100 feet or more from this building and in April 1989 the water's edge was beneath the building (which is built on piles). By 1994, the building was condemned and by the late 1990's had collapsed. This area is the only place on Staten Island underlain by a large body of outwash. Elsewhere, the Pleistocene deposits consist mainly of till. (This is the opposite of the relationships on Long Island, where outwash predominates and till is very localized.)
2. 5 - AKR Excavating Co., 4288 Arthur Kill Road, Kreischerville, Staten Island, about 1 mile N of Outerbridge Crossing. Red-brown till overlying decayed-pebble outwash, which rests on white, charcoal-bearing Cretaceous micaceous sands and gray clays. [UTM coordinates: 564.68E / 4487.42N, Arthur Kill quadrangle.] At this stop we examine geologic relationships that are nowhere else exposed in the New York metropolitan area. These include Pleistocene outwash with spectacular examples of trough cross strata. Among the clasts in this outwash are abundant recycled sedimentary strata including many Newark red-brown siltstones, white quartz, and pieces of the Cretaceous ironstone sandstone and -conglomerate; and rare granitic rocks. The siltstones have been decomposed; they can be easily broken by hand and the feldspars in the granites have been completely decomposed. This decayed-pebble outwash overlies light gray- to white, cross-stratified sand containing lignitic plant debris and interbedded layers of light gray clay (Raritan Formation, Upper Cretaceous, the oldest exposed part of the coastal-plain succession).
3. 6 - Park at Atlantic Highlands, New Jersey, with view into Lower New York Bay from a local park. [UTM Coordinates: 581.75E / 4474.31N, Sandy Hook quadrangle.] Cross-stratified Cretaceous sands are exposed near the parking lot. Depending on the time situation, we may carry out a short dig to show the cross strata.
4. 7 - Cretaceous sand pits behind new furniture store south of Matawan, New Jersey. [UTM Coordinates: 566.38E / 4470.91N, Keyport quadrangle.] The upper parts of the face consist of marine sands, and the lower parts, of sediments from intertidal flats. In the coarse debris at the base of the marine strata are pebbles of ironstone conglomerate.

120 pages · Run: Sunday, 21 May 1989; Saturday, 26 October 1991; Saturday, 29 April 1995

Objectives

1. To study the minerals-, structure, and contact relationships of the Palisades Intrusive Sheet and the Lockatong Formation it has intruded.
2. To learn to distinguish an intrusive sheet from sheet of extrusive igneous rock solidified from an ancient lava flow.
3. To examine the evidence indicating that the paleoflow direction of the Palisades magma was from SW to NE and not from NW to SE.
4. To evaluate the evidence bearing on the state of lithification (or lack of it!) of the sandstones in the Lockatong Formation at the time the Palisades sheet was intruded and from this evidence to estimate the depth of intrusion.
5. To examine pillows--the products of the extrusion of hot lava under a cover of water.
6. To examine the characteristics of the Newark sedimentary strata and to notice the contrast between sediments deposited well away from the Ramapo fault at the northwest basin margin and those deposited close to this basin-marginal fault.
7. To study the composition of boulders in the basin-marginal rudites (general name for any coarse sediment composed chiefly of gravel-size debris, i. e., coarser than 2 mm).
8. To study the evidence for postdepositional faults.

Field stops (4)

1. 2 - Pillow basalt of Orange Mountain Formation ("First Watchung Basalt"). East side of McBride Avenue ~0.7 mile NE of intersection of Glover Avenue and McBride Avenue. [UTM Coordinates: 568.1E / 4528.9N, Paterson quadrangle.] The McBride Avenue exposures are about in the middle of the outcrop belt of the Orange Mountain Formation here. Geologists exploring the sea floor in research submarines been photographed modern pillows forming where lava oozing out of a fissure reacts with the water in such a way that individual pillows are squeezed out, expand, and then separate. The large pillowed part of the Orange Mountain Formation is inferred to have resulted from the extrusion of lava on the bottom of a large lake.
2. 3 - Lower contact of the Orange Mountain Formation ("First Watchung Basalt") and underlying sedimentary strata of the Passaic Formation. [UTM Coordinates: 569.00E / 4529.45N, Paterson quadrangle.] In the low cuts in the parking lot one can see the contact between an overlying mafic extrusive igneous rock (Orange Mountain Formation) and a sedimentary rock (top of Passaic Formation). The contact is not a planar surface but displays considerable irregularity. The direction of in which a sheet of ancient lava flowed can be determined from cylindrical (="pipe") vesicles and -amygdales. Typically these are bent over in the direction toward which the lava flowed. According to Manspeizer (1980), pipe amgydales here are bent over toward the NE. (See Figure 38.) This is the opposite to the direction inferred for the paleoslope of the land surface (based on directions of flow of streams that deposited the cross strata). As a result, the lava here onlapped the regional paleoslope.
3. 4 - The Great Falls of Paterson, Orange Mountain and Passaic formations. [UTM Coordinates: 568.9E / 4529.5N, hillside exposures E and N of stadium: 569.05E / 4529.75N for contact and 569.15E / 4529.85N for cliff face near dog pound, glacial erratic at 568.95E / 4529.65 N, Paterson quadrangle.] The waterfall here drops about 75 feet (from the 120-ft contour at the lip to about 45 ft below). The Passaic River, flowing northeastward (more or less parallel to the strike of the tilted strata), pours into a fracture that trends N-S. The water tumbles over the lip on the rock forming the W side of the fracture, and then flows southward along the fracture, then makes a U-turn and continues flowing NE. No gorge has formed downstream, as has been eroded, for example, by the upstream retreat of the lip of Niagara Falls. In its flow along a fracture and absence of a gorge, Great Falls are a miniature version of the mighty Victoria Falls on the Zambezi River in southeastern Africa (Zambia/Zimbabwe). This stop includes a walk northward beyond the falls to examine sandstones of the Passaic Formation and a large glacial erratic.
4. 5 - Upper, glaciated contact of the Orange Mountain Formation ("First Watchung basalt") at Garrett Mountain Reservation. [UTM Coordinates of old house: 569.50E / 4577.75N, Paterson quadrangle, altitude: 500 feet.] From the crest of the ridge enjoy the splendid view eastward toward Manhattan (atmospheric conditions permitting). Notice the two clusters of skyscrapers: at the Battery and in midtown Manhattan. This is a function of the depth of bedrock. Where the tall buildings have been built, solid bedrock is close to the surface. In between, where no tall buildings have been built, the depth to bedrock becomes several hundred feet. Along the trail, look for vesicles in the basalt (we are near the top of a flow unit where vesicles are to be expected) and the glacial features. Present here are glacial grooves trending NE-SW, about parallel to the trend of Garrett Mountain, and a miniature roche moutonée structure.

46 pages · Run: Saturday, 03 June 1989

Objectives

1. To examine the Hartland Formation of western Connecticut.
2. To locate and discuss glacial features.
3. To discuss the history of mining in western Connecticut.
4. To collect minerals and rocks from famous localities in western Connecticut.
5. Not to get bitten by ticks or mosquitos.

Field stops (4)

1. 1 - Hartland Formation (upper member), Route 8 cuts, Torrington, Connecticut. [UTM Coordinates: 657.0E / 4624.9N, Torrington quadrangle.] The outcrops forming the cliffs across from the commuter lot were originally described by Martin (1970) and subsequently detailed by Merguerian (1985). Here, 2-15 cm-scale very well-layered muscovite-biotite-plagioclase-quartz-(hornblende)-garnet) granofels occurs with interlayered schist of similar mineral composition. The abundance of muscovite in the rocks creates a lustrous sheen from foliation surfaces reflecting sunlight, a hallmark of aluminous Hartland lithologies. The pervasive interlayering of granofels and schist, high muscovite and plagioclase content, and presence of amphibolite suggests that protoliths of these rocks were volcaniclastic graywackes and interlayered shale with subordinate basalt flows.
2. 2 - Harwinton Pegmatite, Harwinton, Connecticut. [UTM Coordinates: 659.1E / 4625.2N, Torrington quadrangle.] Back from the road a quarry was opened in a pegmatite in order to mine for feldspar. Luckily for mineral collectors, the quarry operators selected pure specimens of feldspar and left behind minerals that would interfere with the processing of feldspar. Here, these minerals include whitish to greenish beryl forming six-sided prismatic crystals and groupings up to 20 cm long and 30 cm long black tourmaline (schorl). Permission to collect must be sought from local landowners. Happy hunting !
3. 3 - Thomaston Dam Site, Thomaston, Connecticut. [UTM Coordinates: 660.4E / 4617.4N, Thomaston quadrangle.] The Thomaston dam, a dry dam to hold back flood waters, was built by the U.S. Army Corps of Engineers in 1957 in the aftermath of disastrous flooding of the Naugatuck River valley in 1955. Fractured granite pegmatites and mica schist were exposed in a new railroad cut was made to relocate the rail line west of it's former location. Mineral collectors try to identify veins peripheral to the granite that cut, commonly along joints or faults, across the foliation of the Hartland. During the late stages of magmatic crystallization, large, typically incompatible elements complex with the fluoride and chloride ions and, driven by high vapor pressure, purge through the surrounding country rock leaving well-crystallized mineral samples as vug- and fracture fillings. The common minerals found at Thomaston include fluorite (in various colors), quartz, kyanite, galena, pyromorphite, wulfenite, pyrite, wurtzite (a polymorph of sphalerite), and a host of zeolite minerals including stilbite, harmotone, heulandite, and chabazite. This site is closed to collectors!
4. 5 - Roxbury Garnet Mine, Roxbury Falls, Connecticut. [UTM Coordinates: 641.62E / 4595.95N, Roxbury quadrangle.] The Roxbury garnet mines were operated as small prospect pits in the 1800s(?) and were a major source of garnet abrasive material until the huge discoveries in the Adirondacks near North Creek, New York. The garnets occur as perfect 1-3 cm dodecahedral (twelve-sided) crystals embedded in a crumbly, muscovite-quartz schist and granofels of the Hartland Formation. In some rocks, 1-2 cm tabular brown staurolite crystals coexist with garnet. Mapping by Gates (1959) indicates that the mines occur along the west edge of 1.5-mile lense of similar porphyritic rocks within more typical Hartland occurring on Mine Hill (Stop 4). This site is closed to collectors!

107 pages

Objectives

1. Examine the stratigraphy of southeastern New York.
2. Understand the complex structure and history of faulting in southeastern New York.
3. Discuss the "Taconic controversy".
4. Examine and compare correlative bedrock units northward from New York City.
5. Discuss olistostromes, mélanges, and turbidites with particular reference to the Poughkeepsie mélange.
6. Identify and examine the Taconic unconformity.
7. To appreciate the change in metamorphic grade across the Taconide zone.
8. To discuss plate models for the development of the Taconic range, and identify the probable source area of the Taconic strata.

Field stops (6)

1. 2 - Sauk Sequence of central shelf: Wappinger Group (Cambrian - Ordovician) carbonates. [UTM Coordinates: N/A, Newburgh quadrangle.] Across from the parking areas of Perkins and Burger King occur large cuts of Wappinger carbonates of Cambrian to Ordovician age. These essentially non-metamorphosed rocks are similar to age equivalent rocks of the Inwood Marble of New York City, the Woodville Marble belt of western Connecticut, and the Stockbridge Marble of western Massachusetts. Taken together, these carbonate units constitute the shallow-water Cambrian to Ordovician North American passive-margin carbonate-shelf strata that overlie the Lower Cambrian clastics. Here, the Wappinger carbonates form a well-layered, east-dipping sequence with meter-scale interbedding of dolostone, oolite, and chert with dark-colored ribbony solution residue (stylolites) generally parallel to bedding.
2. 4 - Sauk Sequence: Pine Plains Formation on Lime Kiln Road. [UTM Coordinates: 598.88E / 4500.13N, Hopewell Junction quadrangle.] The Pine Plains Formation was named by E. B. Knopf (1946) when she subdivided the Wappinger Group. Here, the cyclicity of alternating A-B-A-B facies patterns shows up as light- and dark layers(s) which strike NE and dip NW. Similar to Stop 2 (earlier today), the light-colored layers were carbonate sand and the darker layers consisted of carbonate mud. Layers of chert (siliceous ooze), sandstone, and intraformational breccia are common along the length of the exposure. Symmetrical wave-generated ripples occur with ripple crests roughly parallel to the strike direction. Finely laminated layers are the result of carbonate deposition during the formation of algal stromatolites. In addition, evaporite nodules have dissolved to form micro-geodes now filled with calcite, silica, pyrite, and chalcopyrite (the result of burial and dissolution). Burial has also prompted the development of stylolites as branching layer-parallel dark "injections" (cross-cutting dissolution residues) at all scales.
3. 5 - Tippecanoe Sequence: black shale and interbedded graywacke in Mesier Park, Route 9D, Wappingers Falls, New York. [UTM Coordinates: 590.17E / 4605.48N, Wappingers Falls quadrangle.] This will be a brief stop at a convenient place for viewing the weathered massive graywacke layers in the Tippecanoe Sequence (M. Ord.). Here, the graywackes form highly jointed, massive outcrops with approximately north-south strikes and steep easterly to vertical dips. Sedimentary structures include local shaly interbeds, large-scale cross beds, rolling ripple laminae, and amalgamated ripple bedding. These rocks were deposited in the foreland basin that replaced the shallow-water carbonate shelf on which the Sauk Sequence was deposited.
4. 6 - Tippecanoe Sequence: black shale and interbedded graywacke exposed in Wappinger Creek, beneath bridge on Route 9D, Wappingers Falls, New York. [UTM Coordinates: 589.94E / 4605.67N, Wappingers Falls quadrangle.] A short stop (time permitting) to look over the edge of the bridge and examine graywackes differentially eroded by Wappinger Creek. Here, the creek has deeply eroded the shaly interbeds and the massive graywackes form prominent outcrops in the creek bed. Note the potholes formed by swirling waters. With a strike essentially parallel to the south-flowing creek, these beds are oriented steeply eastward to vertical in dip and control the orientation of Wappinger Creek. Also note the building stones used along the bridge. These are potassium feldspar-rich sandstones (arkose) probably from the Newark Basin.
5. 13 - Evidence of progressive metamorphism in the Paleozoic Everett Phyllite, Bashbish Falls, Copake, New York and Massachusetts. [UTM Coordinates: N/A, Bashbish Falls quadrangle.] Be prepared for a half-hour eastward stroll along the north side of Bashbish Creek. Note the nature of the rocks on the trail. These are Taconic slates and phyllites described by Zen and Hartshorn (1966). Near the trailhead the rocks are greenish slates and phyllites rich in chlorite mica. Near Bashbish Falls, the rocks are decidedly of higher metamorphic grade with porphyroblasts of garnet and staurolite sticking up out of the foliation surface and forming a spotted schist. Thus the complete metamorphic lithologic transition from slate to phyllite to schist can be observed along our walk. By the time you reach Bashbish Falls, you have crossed the New York-Massachusetts state line. At the falls, note the foliation on the steeply dipping Everett Schist. The Everett is considered to be of Cambrian to Ordovician age and part of the Taconic allochthon. It rests structurally upon the bedrock of the autochthon consisting of the Walloomsac (=Egremont Phyllite), and underlying Stockbridge Marble.
6. 14 - The Walloomsac Formation (Tippecanoe Sequence, mid Ordovician), NY Route 55. [UTM Coordinates: 613.40E / 4602.51N, Poughquag quadrangle.] The rocks in these long roadcuts have been mapped as Walloomsac Schist by Bence and McLelland (1976; Stop 6 NYSGA) but in their own words, "whether they are, or not, is open to question." The rocks include quartzite, quartz-feldspar gneiss, and biotite-rich schist which contain garnet and kyanite, indicators of amphibolite-facies metamorphism. The kyanite occurs as bluish blades, 3 mm to 2 cm long, particularly concentrated within more-micaceous layers.

111 pages · Run: Saturday, 11 November 1989; Sunday, 24 September 1995

Objectives

1. To study the four major bedrock units exposed in the trip area. From top downward, these are: Layer V, Newark strata; Layer III, Silurian and Devonian; Layer II, where not metamorphosed; and Layer I, Proterozoic of the Ramapo block-Reading Prong. We will start with the oldest unit and study progressively younger units, but see Layer V only in passing.
2. To study the geologic structure, on scales both large and small, with particular emphasis on features found in the post-Taconian strata.
3. To examine the geologic relationships of the local valley-and-ridge type morphology associated with the downdropped Silurian and Devonian strata of the Green Pond-Bellvale-Schunnemunk belt.
4. To understand the relationship between slaty cleavage and bedding in folds.
5. To learn how to use slickensides to infer direction of relative movement on faults.
6. To note any flow-direction features made by glaciers or left in the glacial sediments.

Field stops (8)

1. 2 - Middle Devonian Strata, eastern crest of Bellvale Mountain. [UTM Coordinates: 560.2E / 4566.3N, Greenwood Lake quadrangle]. Our interpretation of the relationships at STOP 2 are based on the results of the 1981 "ad-hoc" Barnard summer geologic "field camp," during which JES instructed a hardy band of 6 (including 3 Barnard junior geology majors) in the fundamentals of field observations and geologic mapping and an advanced undergraduate mapping course in 1997 at Hofstra University conducted by JES and CM. The mapping projects started at STOP 2 and progressed northeastward along the crest of Bellvale Mountain, with emphasis on three units: the graded graywackes of the lower Bellvale, the coarsely cross-bedded graywackes of the Upper Bellvale, and the quartzose, pebbly Schunnemunk Conglomerate. Topics discussed in the guidebook include characteristics of steeply dipping graywackes of the lower Bellvale and coarse, quartzose Schunnemunk Conglomerate; plant debris in the graywackes; upward-fining cycles in the Schunnemunk; evidence for original top direction of steeply dipping strata; "technicolor" slickensides; and inferred direction of fault movement.
2. 3 - Schunnemunk Conglomertae and Upper Bellvale Formation, NY 17A, western crest of Bellvale Mountain. [UTM Coordinates: 559.6E / 4565.9N, Greenwood Lake quadrangle.] In view of the scenic panorama to the NW are isolated knobs composed of Proterozoic rocks (klippen), the Appalachian Great Valley, Schunnemunk Mountain (to the NE), and the Shawangunk-Kittatinny ridge in the far distance. In exposures behind us the rocks here are typical Schunnemunk, with upward-fining cycles starting with pebbles at the base and grading up into shale. Notice the irregular bases of the pebbly layers, the clasts of red slate (as well as of white quartz), and the cross strata. Two cleavages are present here. As usual, the slaty cleavage is best developed in the fine-textured strata. Notice what becomes of the cleavage in the coarser layers.
3. 4 - Tippecanoe Sequence (Martinsburg Slate), County Route 1, west of Warwick, New York. [UTM Coordinates: 592.8E / 4568.3N, Warwick quadrangle.] The purpose of this stop is to demonstrate the relationship between slaty cleavage that is parallel to the axial plane of a fold and the bedding, and also to examine the Bushkill Member of the Martinsburg Formation. Notice that in the axial part of the fold (crest of an anticline or trough of a syncline), the slaty cleavage cuts the bedding at a high angle.
4. 6 - Coarse-textured Tippecanoe Sequence - either the Ramseyburg (M. Ord.) or the High Point (U. Ord.) Members of the Martinsburg Formation. Cuts in Ramps at I-84 interchange at Mountain Road and Smith Corners. [UTM Coordinates: 532.3E / 4579.1N, Unionville quadrangle.] Here we approach the NW side of the Appalachian Great Valley and its bounding strike ridge underlain by NW-dipping Lower Silurian conglomerate/sandstone. Along this side of the Great Valley, the dips of Ordovician and Silurian strata typically are the same; we are outside the belt of Taconian folds. The coarse Martinsburg strata here display the features of what geologists refer to as a "flysch." The coarse layers commonly show grading; their bases are sharp and may display indications that the current which deposited the coarse sediment interacted with the muddy bottom over which it flowed. See how many features you can find that were made by currents, either now preserved as counterparts on the bases of the sandstone beds or within them, and what conclusions you can draw about the direction of flow of the currents on the Ordovician sea floor.
5. 7 - Shawangunk Formation, High Point State Park, New Jersey. [UTM Coordinates: 528.35E / 4574.25N, Port Jervis quadrangle.]
6. 7 is another rocks-plus-scenic-vista locality. The Shawangunk and underlying Martinsburg here have been closely folded together, an arrangement that is not typical of the monoclinal strike ridge to the NE and SW. Our purpose is to examine the massive sandstone/conglomerate, look for sedimentary structures to indicate tops, and to relate this resistant formation to its topographic expression.
7. 8 - Upper Cambrian part of the Sauk Sequence (Cambro-Ordovician carbonates). Roadcut along NJ Route 94, Hamburg, New Jersey. [UTM Coordinates: 534.30E / 4455.45N, Hamburg quadrangle.] The features to see here include the alternating coarse-fine layers and the characteristics of each, plus their mutual interpenetration along stylolite seams and the chert. Layers that consist of original sand-size sediment contain quartz, intraclasts of the former lime mud, and ooids. Cross laminae are common. The finer-textured layers are well laminated. Algal stromatolites characterize certain layers. The repeated pattern of couplets of coarse- and fine layers has been interpreted as being the result of upward shoaling from a subtidal environment to an intertidal/supratidal environment.
8. 9 - SE-vergent anticline in the Green Pond Formation, SE of Newfoundland, NJ. Roadcut in the median of NJ Route 23. [UTM Coordinates: 547.4E / 4542.7N, Newfoundland quadrangle.] This splendid exposure enables one to examine the crest of an anticline that is totally accessible. Trace the layers carefully and see if they are as continuous as they might seem to be. Notice the direction of asymmetry of the folds; the steep limbs are on the SE and the gentler limbs on the NW, just the opposite of most Appalachian folds. This area is part of the Green Pond outlier where the width of the outcrop of the Green Pond belt increases so that all the strata from the Green Pond to the Schunnemunk are present. The wider outcrop belt also coincides with the localities in which the basal Silurian cuts across the older Paleozoic strata to rest on the basement.

Run: Saturday, 12 May 1990; Saturday, 21 November 1992

Objectives

1. To examine the depositional features in the deltaic sediments at Croton Point Park.
2. To compare and contrast the red-brown tills with those having colors other than red-brown.
3. To study the gray varved clays that were deposited in the same lake into which the delta grew, but that were protected by higher-standing parts of the former lake bottom (underlain by till) from the influx of sand from the east.
4. To relate the modern depositional setting (intertidal marsh, beach, and boulder-strewn flats) to the Pleistocene sediments.
5. To infer a chronology of events that took place during the Pleistocene glacial age(s) and the Holocene.
6. To study the boulders washed out of the till(s) as indicators of provenance. In this respect, we will concentrate on the kinds of mafic rocks derived from the Cortlandt Complex, a pluton near Peekskill, and the surrounding country rocks, and,
7. To examine the bedrock geology in the vicinity of Peekskill Hollow, a source for many of the boulders in the NNE-derived tills exposed to the south.

Field stops (4)

1. 5 - Igneous flow layering in norite, Pluton V of Cortlandt Complex. [UTM Coordinates: 588.94E / 4568.78N, Peekskill quadrangle.] The purpose of this stop is to examine flow layering in igneous rocks of Pluton V (norite) of the Cortlandt Complex. We are situated at the western edge of the Central Basin of Balk (1927). Here notice the well-developed, northeast-dipping coarse- to medium-textured norite with an igneous flow layering. The layers consist of plagioclase laths (reddish tint) and hypersthene (an orthopyroxene). Note the northeast-dipping lithologic contact between texturally and mineralogically different phases within the igneous rock, the presence of schlieren (mafic clots), and the compact, dense mafic rock here. Are you convinced that bedrock such as some of the coarse layers exposed here could have supplied some of boulders we have just examined at Croton Point?
2. 6 - Glaciated Inwood Marble and Manhattan Schist? [UTM Coordinates: 587.29E / 4567.44N, Peekskill quadrangle.] Low outcrop on the north side of 11th Street of dolomitic- and calcitic Cambro-Ordovician marble exhibiting glacial grooves and scratches. On the south side of the street occurs marble plus phyllite also showing glacial striae and grooves. We think it's the Annsville Phyllite.
3. 7 - Poikilitic flow-layered norite (Pluton V) with xenolith of isoclinally folded, contact-metamorphosed Inwood marble. [UTM Coordinates: 589.65E / 4570.3N, Peekskill quadrangle.] Orthopyroxene-bearing gabbro (norite) of Pluton V of the Cortlandt Complex here exhibits poikiloblasts of primary igneous kaersutitic amphibole ranging from 1-4 cm and averaging 2 cm in size. Within the norite occurs an elongate xenolith of tightly folded, contact metamorphosed Inwood (Wappinger equivalent) Marble.
4. 9 - Poughquag Quartzite. (Optional, time permitting). [UTM Coordinates: 589.82E / 4559.9N, Peekskill quadrangle.] Here, hopefully up-wind from the sewage treatment plant on the day of our trip, note the gently east-dipping thinly laminated bedding and sub-parallel foliation of the Poughquag Quartzite. The quartzite is of Early Cambrian age; it represents the basal part of the Sauk Sequence (deposits of former Early Paleozoic shelf). The Poughquag is a dense, hard, fine- to medium-textured quartzite that ranges in color from white to tan and brown to reddish (Schaffel, 1958). Local conglomeratic facies contain distinctive bluish quartz pebbles. As such, this outcrop belt of the Poughquag (and perhaps its northern correlative--the Cheshire Quartzite) are the probable parents for many of the resistant quartzite (+/- hematite stained) boulders that we found had been eroded from the tills at Croton Point Park.

103 pages

Objectives

1. To familiarize you with the variety and depositional history of the Silurian and Devonian strata of Layer III in New York State.
2. To examine and understand the northeasterly stratigraphic thinning and ultimate pinchout of these units in comparison to their temporal equivalents toward the southwest.
3. To get close and personal with anticlines, synclines, faults, and other geologic structures.
4. To examine and use in the determination of topping direction, sedimentary structures such as graded beds, ripple marks, cross beds, etc.
5. To examine and marvel at the Taconic unconformity at a number of places.
6. To observe and hopefully, collect fossils from the Siluro-Devonian strata.
7. To perform a series of exercises in geologic mapping and compass techniques.
8. To test, in the field, the application of the PAC hypothesis in understanding sedimentation.
9. To witness, in a 350-million-year flashback, the depositional history of the Lower Paleozoic strata and to note the change from marine- to non-marine sedimentary successions, and,
10. To visit all of our intended field trip stops (Fat Chance! But 9 out of 10 isn't bad).

Field stops (8)

1. 6 - Binnewater Sandstone and High Falls Shale in east-vergent monoclinal flexure, High Falls hydroelectric station. [UTM Coordinates: 571.91E / 4630.95N, Mohonk Lake quadrangle.] Walk through fence maze to the fence nearest the falls. This area has been restored and made available by Central Hudson Gas and Electric Corp and the High Falls Civic Association. At the upper Falls, the lip is composed of the Rosendale Dolostone with Binnewater Sandstone just below, both dipping NW (upstream). Beneath the Binnewater is the High Falls Shale with cuts here on the N side of creek marking the type locality. Walk down blacktop path to lower level. Exposed on R is cliff of Binnewater Sandstone, with dip to NW. Near the bottom is the contact with the High Falls Shale. A noteworthy feature of the asymmetric fold on opposite bank of creek is that the fold axial surface dips NW (opposite to the SE dip of most Appalachian folds). CM and JES suggest that this anticline has developed over a ramp up to a bedding-plane thrust that duplicates the Rosendale-Binnewater-High Falls succession here.
2. 7 - Williams Lake Hotel transect through plunging folds. [UTM Coordinates: 576.3E / 4535.0N, Rosendale quadrangle.] This is a free-form stop with no notes, but we will traverse the old railroad bed to map the lithology and structure of the rocks exposed here. The section starts with Shawangunk Conglomerate and proceeds upward through the High Falls Shale, Binnewater Sandstone, Rosendale Dolostone, Glasco Limestone, Whiteport Dolostone, and Manlius Formation. Note that this area marks the northernmost exposure of the Shawangunk which pinches out somewhere between the Fifth and Fourth Binnewater Lakes. We will examine many geologic features, including sedimentary structures, bedding-plane thrusts, bedding-cleavage relationships, and folds and you will be rewarded with a lovely trip through the plunging folds (literally). We will walk up section into the Helderbergian limestones which you will see in more detail tomorrow. This site is currently private property though the public Rail Trail will take you through the area.
3. 10 - Taconic Unconformity and bedding-plane thrusts in Helderbergian carbonates, NY 32, East Kingston. [UTM Coordinates: 585.1E / 4646.82N, Kingston East quadrangle.] At Stop 10, we see all parts of the Rondout Formation, with base resting on the Taconian unconformity, as at Stop 9, but with the added factor of repetition of the Siluro-Devonian strata along a number of bedding-plane thrusts. We will work our way along the large rock face beginning at the N end with the Ordovician strata. Steeply north-dipping extension fractures (related to the ramp-like thrusts) are lined with calcite. We note minor normal reactivation of some of the bedding plane thrusts based on left-lateral offset of steep, post-thrust calcite veins.
4. 11 - Helderberg Strata on N side NY Route 199, on W approach to Kingston-Rhinecliff Bridge. [UTM Coordinates: 585.05E / 4647.5N, Kingston East quadrangle.] At this stop, the bottom of the Helderberg carbonates is not visible, but we can see the upper part of the Manlius (Thacher Member) and all three units of the lower fining-upward cycle of Coeymans (Ravena Member)-Kalkberg (lower Hannacroix and upper Broncks Lake members)-New Scotland. See what you can find in the way of fossils here. The best specimens may not be in the fresh bedrock, that breaks so irregularly, but in the weathered blocks at the top of the ridge. Study of the molds and casts in fine-textured rocks can yield nearly as much detail as study of fossils in which the original skeletal material is intact.
5. 12 - Anticlinal Fold of Helderberg Strata, on N side of NY Route 199, W approach to Kingston-Rhinecliff Bridge. [UTM Coordinates: 584.75E / 4647.38N, Kingston East quadrangle.] This small anticline brings up the strata of the upper fining-upward cycle, the Becraft-Alsen-Port Ewen beds. The anticline is separated from the strata at Stop 11 by a fault that follows the low covered interval between the two ridges where rock is exposed along the highway. Notice the comparable relationships of a coarse, gray, skeletal limestone without much silt and lacking chert in the basal unit (Coeymans and Becraft). This grades upward into a siltier rock containing chert (Kalkberg and Alsen). At the top, the chert vanishes and the rock is a shaly calcareous siltstone (New Scotland-Port Ewen).
6. 13 - Mount Marion Formation, New Cut on NY Route 32, Quarryville (N of Mt. Airy). [UTM Coordinates: 584.0E / 4363.15N, Saugerties quadrangle.] This cut exposes the same formation we examined at Stop 8, a deep-water marine deposit consisting of dark gray to black shale, siltstone, and sandstone somewhat resembling the Ordovician flysch. Very little shale is exposed at the W end of the exposure. Rather, non-graded and non-laminated massive sandstone and siltstone occurs. Note the rounded, dense concretions which consist of pyrite, siderite, and possibly barite. Look for Devonian brachiopods in the sandy layers. Check closely to see if any bedding-plane thrust faults repeat any layers, as observed at Stop 8.
7. 14 - Ashokan Formation, NY Route 32, W of Quarryville. [UTM Coordinates: 583.13E / 4663.6N, Saugerties quadrangle.] The Ashokan Formation is the formation quarried as New York blue stone and is used for paving slabs on sidewalks. Notice the well-developed large-scale cross strata that show stream flow toward the west. JES thinks that the Mount Marion-Ashokan combination is equivalent to the Bellvale Formation of the Schunnemunk-Green Pond belt, with lower Bellvale equal to Mount Marion and upper Bellvale, to the Ashokan.
8. 16 - Taconic Unconformity and overlying Rondout and Helderbergian carbonates, N side of exit ramp from new location of NY Route 23 from Rip Van Winkle Bridge to old NY Route 23, Jefferson Heights, Catskill. [UTM Coordinates: 591.9E / 4676.6N, Cementon quadrangle.] Here, the Rondout Formation and Helderbergian carbonate succession are in marked steeply-dipping unconformity with underlying Ordovician graywackes. The Rondout Formation consists of about 1 m of Rosendale Dolostone with a thin basal sandstone (Binnewater?) resting on the steeply dipping Ordovician Tippecanoe sequence. Overlying the Rosendale is roughly 10 cm of limestone that is probably the feather edge of the Glasco Limestone, followed by the Whiteport Dolostone. Thrust faults occur above the Whiteport in a chaotic zone with right-lateral shear sense, characterized by intrafolial isoclinal folds and then the chaotic sequence is capped by the highly laminated Manlius (Helderbergian) Limestone follwed by the Coeymans and Kalkberg limestones. Note that the Shawangunk, High Falls, Binnewater, Wilbur sequence is absent and that what is left of the Silurian is exceedingly thin.

139 pages · Run: Sunday, 17 June 1990; Sunday, 29 October 1995

Objectives

1. To drive across and observe the Mesozoic rocks of the Newark Basin at 55 mph.
2. To examine the Cambro-Ordovician shelf deposits Kittitinny dolomitic carbonates of Passive Margin I.
3. To examine evidence for glaciation and glacial deposition in the Wallkill valley and discuss the drainage history of the region.
4. To contrast and compare the Paleozoic and Proterozoic marble units and to discuss their paleoenvironments.
5. To examine the Proterozoic rocks paying particular attention to the host rock for the Franklin-Sterling Hill orebodies and to discuss their genesis.
6. To visit the world-famous Sterling Hill Mine site and the Franklin Mineral Museum for guided tours and, time permitting collecting, and,
7. To get close and personal with folds, faults, and surfaces of unconformity.

Field stops (3)

1. 3 - Sterling Hill Mine, Ogdensburg. [UTM Coordinates: 532.9E / 4547.9N, Franklin quadrangle.] Mr. Richard Houck, owner of the Sterling Hill Mining Company and tour guide/lecturer, re-opened the mine as a tourist attraction on 01 July 1990, about two years after it was closed in September of 1988. Of further benefit, Dr. Bob Metsger, former Chief Geologist (in the years 1949 to 1988) for the New Jersey Zinc Company at Sterling Hill and currently geologist for the New Jersey Geological Survey, has agreed to meet us at the mine and provide a guided tour of the mine area. As such, CM and JES have little to say here and will allow the area experts to provide the details. This is a great place for an outing with family and friends where a world-class mineral deposit is on display!
2. 6 - Franklin Mineral Museum Lecture, Tour, and (Time-Permitting) Collecting at Buckwheat Dump. [UTM Coordinates: 534.58E / 4551.26N, Franklin quadrangle.] We have made an arrangement with Mrs. Carol Hunsinger (Manager) and Steve Sanford, curator of the Franklin Mineral Museum, to enjoy a guided tour and lecture of the museum. There are specimens for sale in his shop and a phenomenal collection of Franklin/Sterling Hill mineral specimens on view in the museum including the Bill Welsh collection. Time permitting (and for a $3.00 fee) you will be permitted to collect fluorescent minerals from the Buckwheat Dump immediately west of the museum. Just behind here is the old open pit of the Franklin Mine. The underground workings of the mine (which form a labyrinth beneath the town of Franklin) were closed in 1954. In the distance is a narrow cut beyond which occurs a subvertical lamprophyre dike 20 ft thick, which encloses xenoliths of Franklin ore. Strangely, the willemite-bearing xenoliths still fluoresce despite the fact that high heat typically destroys the fluoresence of willemite.
3. 8 - Ramapo Border Fault, Exposed in New Cuts, I-287. [UTM Coordinates: 558.0E / 4537.6N, Pompton Plains quadrangle.] This is a free-form stop where we will examine new exposures of the Ramapo Fault. Here, the Proterozoic gneisses consist of quarto-feldspathic, amphibolitic, and granitoid gneisses that are strongly retrograded to epidote-rich rocks. The exposure is cut by surprisingly few brittle faults. Thus, despite the fact that we are within the Ramapo fault zone only a few faults have been observed. These faults dip steeply toward the east and contain slickensides that plunge toward the northeast. We have not examined these rocks in detail, however, and will discover and discuss our findings On-The-Rocks.

115 pages · Run: Saturday, 23 September 1990

Objectives

1. To examine the Hartland and Waramaug formations of western Connecticut.
2. To study mafic- and ultramafic rocks of the Hodges Complex and the younger Tyler Lake Granite.
3. To establish the contact relationships of these plutons to each other and to Cameron's Line.
4. To identify slivers of ophiolite and to compare them to the mafic- to ultramafic igneous rocks of the plutons.
5. To illustrate methods of analyzing geologic structures in rock that have been complexly deformed.
6. To locate and discuss glacial features.
7. Not to get bitten by ticks or mosquitos, and,
8. To visit all of our field trip stops (Fat Chance!).

Field stops (6)

1. 1 - Hartland Formation (upper member) granofels, schist, and amphibolite. [UTM Coordinates: 656.80E / 4624.88N, Torrington quadrangle.] The outcrops forming the cliffs across from the commuter lot were originally described by Martin (1970) and subsequently detailed by Merguerian (1985). Here, 2-15 cm-scale very well-layered muscovite-biotite-plagioclase-quartz-(hornblende)-garnet) granofels occurs with interlayered schist of similar mineral composition. The abundance of muscovite in the rocks creates a lustrous sheen from foliation surfaces reflecting sunlight, a hallmark of aluminous Hartland lithologies. The pervasive interlayering of granofels and schist, high muscovite and plagioclase content, and presence of amphibolite suggests that protoliths of these rocks were volcaniclastic graywackes and interlayered shale with subordinate basalt flows.
2. 2 - Hartland Formation (lower member) amphibolite and subsidiary D2 shear zone. [UTM Coordinates: 651.75E / 4629.13N, West Torrington quadrangle.] The roadside exposures consist of fine- to medium-textured, dark-green hornblende-plagioclase-biotite-(quartz)-(epidote)-(chlorite)-(garnet) amphibolite with lineated prismatic hornblende. Elliptical quartz segregations up to 4 cm thick lie within the S2 foliation. Elsewhere, felsic granofelsñhornblende, +/- biotite, +/- chlorite in layers 1 to 2 m thick, are interlayered with the amphibolite and the muscovitic schist. Walk 110 m west on Soapstone Hill Road where amphibolite exposures exhibit S2 mylonitic layering. Between these exposures, the muscovite schist is phyllonitic and thin. The mylonitic textures may mark a subsidiary D2 shear zone that imbricates the Hartland amphibolite. Alternatively, shearing could simply have been the result of ductility contrasts developed across the amphibolite-schist contact.
3. 2a (Optional) - Soapstone Quarry. [UTM Coordinates: 653.63E / 4629.55N, West Torrington quadrangle.] Walk north on a dirt trail immediately west of the parking area for Stop 2. Along the way, ridges are composed of amphibolite and the intervening valleys are underlain by muscovitic schist. Roughly 700 m north, the trail ends at a pit, of a former soapstone quarry, that is 90 m long by 20 m wide. (They don't call it Soapstone Hill Road for nothing, you know!). The excavation, which is oriented parallel to S2 in the bounding muscovite-chlorite schist, produced commercial quantities of soapstone. Blocks from the tailings pile include talc-tremolite schist, chlorite schist, and very coarse amphibolite rich in opaque minerals.
4. 3 - Hartland Formation (lower member) muscovite-kyanite-staurolite schist. [UTM Coordinates: 651.10E / 4629.12N, West Torrington quadrangle.] The lower-member Hartland schist crops out less than 50 m north of the road. The rocks are highly lustrous, gray-weathering, medium- to coarse quartz-muscovite-plagioclase-biotite-opaque-(garnet)-(chlorite)-(apatite) schists often containing 1-to 10-cm porphyroblasts of kyanite, staurolite, and garnet, and more rarely, plagioclase and biotite. The proportions of quartz and muscovite are roughly equal. Together, these two minerals constitute more than half the rock. Granular, clear- to smoky-gray quartz pods are conspicuous and have been flattened into S2. The rocks are lithically correlative with the Rowe Schist of western Massachusetts.
5. 6 (Optional) - Mafic and ultramafic rocks of the Hodges Complex. [UTM Coordinates: 652.15E / 4632.64N, West Torrington quadrangle.] As we walk up the overgrown trail westward from Weed Road, notice that the hill to the west is primarily composed of hornblende gabbro. Locally, this rock is melanocratic and its texture, porphyritic. Concentrations of mafic minerals and oriented hornblendes define a west-dipping flow layering. Near the top of the hill and in a small pod to the south, coarse pyroxenite and hornblendite crop out. Here, the intrusives mask Cameron's Line. But based on detailed tracing of screens and xenoliths, CM infers that Cameron's Line crosses the top of the hill in a SSW direction. The Hodges rocks are in contact with both the Waramaug and Hartland to the west and east, respectively. To the west, near exposures of the Waramaug, flow-layered diorite trends NE and dips vertical to steep. The Waramaug consists of a dense hornfels peppered with garnet. Despite these contact-mineral changes, the characteristic nubby weathering is still preserved. Along the western slope of the 1320' hill, the Waramaug contains white tremolitic calc-silicate layers.
6. 8 - Tyler Lake Granite. [UTM Coordinates: 653.00E / 4631.34N, West Torrington quadrangle.] Near the creek bed is exposed tan-weathering, medium-grained, foliated quartz-microcline-plagioclase-muscovite-biotite-garnet-(chlorite)-(apatite) granite. An X-ray- fluorescence analysis by Dr. D. Radcliffe of Hofstra University produced the following result: SiO2 = 73.0, Al2O3 = 14.2, Fe2O3 = 1.4, MgO = 0.6, CaO = 0.8, K2O = 5.5, Na2O = 3.1, TiO2 = 0.2, MnO = 0.1, loss on ignition = 0.7 (total = 99.6). The granite has been foliated by cm-spaced micaceous layering (S4). The Tyler Lake Granite contains xenoliths of the Hodges rocks and is in direct contact with all major metamorphic units in the area (except C-Ohmk and C-Oha). This suggests a young intrusive age. Widely separated sample suites from the granite yield a well defined 466 +/- 12 Ma Rb-Sr isochron with initial Sr 87/86 = 0.7082 +/- 0.0011 (Merguerian and others, 1984). Because the Hodges was intruded following or nearly synchronously with D2, this mid-Ordovician age is proof of a Taconian or possibly older age for Cameron's Line.

133 pages

Objectives

1. To examine the Cretaceous strata of northern Long Island. To study the relationships of the Quaternary sediments to the modern landscape.
2. To study the provenance of glacial erratics, especially of stones found on Long Island's north-shore beaches and facies changes in the Quaternary sediments.
3. To demonstrate the importance of lacustrine-deltaic strata in Fuller's Manhasset Formation.
4. To emphasize the general correctness of Fuller's interpretation of the stratigraphy compared with those who have cast Fuller aside, and,
5. To understand the general geologic relationships of the geologic units on Long Island and the occurrence of ground water in various geologic units.

Field stops (2)

1. 5 - Target Rock National Wildlife Refuge, West Neck Road, Lloyd Neck. [UTM Coordinates: 632.0E / 4531.8N, Lloyd Harbor quadrangle.] En route, the trail crosses the loess, which forms the topmost layer of the cliff exposures (as seen at the N end of the Preserve). The Target Rock exposures were described in Sirkin and Mills (1975, p. 319-323), who illustrated two tills and some laminated silts/clays in between. We have interpreted these laminated fine sediments as deposits of Lake Long Island (Sanders and Merguerian, 1994a; Sanders, Merguerian, and Mills, 1993). The beach here contains abundant green pebbles featuring porphyritic volcanic rocks that we think came from W of New Haven, CT (Maltby volcanics). They are definitely not trap rocks from the Palisades, as suggested by Sirkin and Mills. They imply glacial flow from NNE to SSW, not NNW to SSE. The lower half of the cliff exposed after the storms of December 1992 consists of till containing green porphyritic mafic erratics, so common on the beach. We correlate this till with the oldest till at Croton Point Park (the gray till containing decayed granite stones; Merguerian and Sanders, 1992b; Sanders and Merguerian, 1994b).
2. 7 - Jacobs Hill, Southold. [UTM Coordinates: 702.2E / 4540.5N, Mattituck quadrangle.] Assemble at the SE corner of the parking lot for a walk down the trail to the beach. Assemble by the van for a brief look at the topographic map of the Mattituck- and Mattituck Hills quadrangles. Notice that the houses shown on the Mattituck quadrangle map dated 1955? are no longer present. They probably disappeared during the big storms of December 1992, but we do not know this for certain. Geologic descriptions of the locality referred to simply as "Jacob Hill" have been published by Fuller (1914) and by J. E. Upson (1970) of the U. S. Geological Survey. Fuller made this the type locality of the Jacob Sand, which overlies the Gardiners Clay. (Both of these formations underlie the Manhasset Formation.) A notable feature of the cliff here is the till at the top that contains large boulders, many of which now litter the beach. This is the Montauk Till of Fuller's Manhasset Formation. This till is overlain by the ubiquitous loess.

118 pages · Run: Sunday, 21 May 1991; Saturday, 20 May 1995

Objectives

1. Examining the regional stratigraphy and structure of the Appalachians in the vicinity of northwestern New Jersey.
2. Identifying evidence for Late Paleozoic (terminal-stage Appalachian) deformation in both the Great Valley and Valley and Ridge Province.
3. Taking a leisurely walk through a part of Stokes State Forest for a detailed look at folds, faults, and superposed cleavage.
4. Pointing out evidence for large-scale overthrusts of Paleozoic and older strata during protracted Phanerozoic orogeny.
5. Looking for glacial features and indicator stones to develop ideas on superposed glaciation for this part of northwestern New Jersey, and,
6. To get to all of our intended stops for the day (we think we have a good chance at this one, for a change!)

Field stops (2)

1. 4 - Martinsburg slates, Hampton Township. [UTM Coordinates: 523.05E / 4550.55N, Newton East quadrangle.] Before you is a marvelous example of an anticline in dark- colored slates of the Martinbsburg Formation. Note the very prominent "pencil" structure here because the bedding and the cleavages break the rock into extremely long pieces. Let's look for evidence for another (third?) slaty cleavage or two and try to find some nice slate specimens showing a high angle bedding/cleavage relationship.
2. 5 - Sauk Sequence (Cambro-Ordovician) carbonates thrust over Martinsburg slates ("Jenny Jump thrust"), Newton County Mall. [UTM Coordinates: 521.60E / 4546.60N, Newton East quadrangle.] The area of this stop was described in detail by Drake and Lyttle (1980; Stop 9) and we borrow liberally from their discussion. Here a small slab of Allentown Dolostone (Upper Cambrian part of the Sauk Sequence) lies structurally above slates of the Tippecanoe Sequence [Ramseyburg Member of the Martinsburg Formation (part of our Layer IIB)]. The contact is a thrust fault (the Jenny Jump thrust of Lewis and Kummel (1915), and Kummel (1940), and renamed the Grand Union thrust by Drake and Lyttle 1980). This marvelous, but somewhat non-picturesque, exposure was created during excavation for the shopping center. The thrust is marked by 2 to 8 cm of gouge consisting of crushed, slickensided dolostone.

111 pages · Run: Sunday, 16 June 1991; Sunday, 18 June 1994

Objectives

1. To collect minerals from the Case beryl prospects in Portland, Connecticut.
2. To examine the stratigraphy of the Hartford Basin of central Connecticut.
3. To discuss the structure of the Hartford Basin.
4. To locate and discuss glacial features, and,
5. To avoid being bitten by ticks or mosquitos.

Field stops (2)

1. 2 - Dinosaur State Park at Rocky Hill. [UTM Coordinates: 695.3E / 4613.6N, Hartford South quadrangle.] During the Jurassic Period, roughly 185 Ma, mudflats extended over much of the flat floor of the Hartford basin. Fault-related uplifts along the eastern basin-marginal fault of this basin provided intermittent supplies of coarse clastic sediments eroded from the pre-Triassic crystalline rocks of the persistently elevated Eastern Highland block. Into the Hartford basin poured many sediments that we now see as interbedded red sandstones, shales, conglomerates and non-red-colored lacustrine deposits. Many dinosaurs traversed these muddy plains searching for food (not mineral specimens as had been commonly thought!) and left tracks in their wake. Fossil bones of these dinosaurs have never been found as the conditions that preserve tracks are not the best for preserving bone, but the search continues. The geodesic dome constructed here preserves a multitude of tracks for the public to see and admire. We will stop here for lunch and, time permitting a brief visit to the dinosaur footprint area where you may create a plaster cast of a Eubrontes footprint.
2. 4 - Hampden Basalt and East Berlin Formation, East Berlin. [UTM Coordinates: 688.5E/ 4610.2N, Middletown quadrangle.] Exposed here are the upper layers of the East Berlin Formation (this is the type locality so designated by E. P. Lehmann in 1959) and contact with overlying Hampden Basalt (the same units as at Stop 3, but repeated here by being relatively downdropped about 2000 feet on a normal fault). Some large and splendid glacial grooves are visible at top of knoll on NE side of the road. The lower part of the Hampden Basalt contains bent-over pipestem vesicles that indicate the direction of flow of the lava before final cooling. We will use a compass to record the direction implied. Notice the "vesicles" in the underlying siltstone!

126 pages · Run: Sunday, 24 November 1991; Saturday, 08 May 1993

Objectives

1. To study the effects of extreme folding, faulting and metamorphism of the Lower Paleozoic strata of the Bronx.
2. To examine lithologic variations in the three schist units of the Bronx formerly "lumped" together into the Manhattan Formation.
3. To examine the evidence for Cameron's Line.
4. To get up close and personal with mylonitic rocks.
5. To examine the effects of multiple glaciations.
6. To get in the groove, glacial-, that is!
7. To find sufficient restrooms to keep field trip participants happy, and,
8. To try to visit all of our planned stops.

Field stops (13)

1. 2 - Cameron's Line or the St. Nicholas Thrust - Boro Hall and Crotona Parks, Cross Bronx Expressway, The Bronx. [UTM Coordinates: 592.94E / 4521.75N, Central Park quadrangle.] Most of the Paleozoic rock units of the NYC area converge in and around Boro Hall and Crotona Parks in The Bronx according to our previous and ongoing research efforts. In these small parks, separated by I-95, marble, calc-schist, granofels, gneiss, and mica schist are all exposed from west to east in NE-striking, imbricated ductile-fault bounded tectonostratigraphic units.
2. 3.1 - Hartland Formation on the east side of Bronx River beneath Hester Bridge.
3. 3.2 - Migmatitic Hartland Formation on east side of Bronx River at waterfall area.
4. 3.3 - Roche-moutonée structure in the Hartland Formation.
5. 3.4 - Stratigraphy of the Hartland Formation and evidence for glaciation.
6. 3.5 - Shallow early structures in the Hartland Formation and evidence for two glaciations.
7. 3.6 - Elephant Rock--a trunkful of crescentic- and lunate gouges, erratics, and striae in deformed Hartland rocks.
8. 3.7 - Lincoln Rock - Two glacial directions and local flow divergence.
9. 3.8 - Well layered (mylonitic?) Hartland cut by a prominent joint set.
10. 3.9 - Dolerite erratics.
11. 3.10 - Manhattan Schist Formation.
12. 3.11 - Hartland Formation and amphibolite float.
13. 3.12 - Mylonitic Manhattan Formation and the elusive Inwood Marble.

109 pages · Run: Saturday, 20 June 1992

Objectives

1. Examining the regional stratigraphy and structure of the Appalachians in the vicinity of northwestern New Jersey.
2. Identify evidence for Late Paleozoic (terminal-stage Appalachian) deformation in the Great Valley and Valley and Ridge Province.
3. Taking a leisurely walk through a part of the Delaware Water Gap National Recreation Area for a detailed look at folds and superposed cleavage.
4. Pointing out evidence for large-scale overthrusts of Paleozoic and older strata during protracted Phanerozoic orogeny.
5. Looking for glacial features along the walls of the Delaware Water Gap, and,
6. To get to all of our intended stops for the day.

Field stops (11)

1. 1 - Proterozoic rock cuts on exit ramp from rest area/truck-parking area on I-80 westbound, Town of Allamuchy, NJ. [UTM Coordinates: 518.0E / 4530.3N, Tranquility quadrangle.] The rocks here are part of the Allamuchy nappe of Drake and Lyttle (1980, p. 98), of which they wrote: "The Allamuchy nappe is typical of the other crystalline-cored nappes de recouvrement of the Reading Prong nappe megasystem as described to the west. Exposed here is a coarse felsic gneiss displaying effects of extensive brittle deformation. Almost all rock faces are limonite-lined fractures (probably a result of oxidation of original pyrite films). Near the E end of the cuts are steep normal faults, that strike parallel to I-80 (NE-SW) and dip steeply SE on which dip-slip slickensides are well developed. By the guard rail, the gneissic foliation is clear; its strike is roughly perpendicular to I-80 and its dip is to the NE. Near the drain pipe at the end of the cut is a splendid example of a fault-mirror slickenside displaying right-lateral strike slip offset.
2. 2 (Optional) - Scenic Overlook on I-80 westbound. [UTM Coordinates: 516.0E / 4530.2N, Town of Allamuchy, NJ, Tranquility quadrangle.] At the breathtaking elevation of 1100' above sea level, we may be able see through gaps in the trees a panoramic vista toward the NW across the Great Valley (here named the Kittatinny Valley; it is underlain by the Sauk Sequence carbonates and limestones/slates of the Tippecanoe Sequence) to the Delaware Water Gap, which cuts through the otherwise-unbroken ridge along the NW side of the Appalachian Great Valley. This ridge is underlain by massive Lower Silurian conglomerate and sandstone units that generally dip to the NW. Note that the elevations of the tops of the local mountain ridges are all approximately the same height. Such summit accordance is indicative of prolonged erosion and development of a planation surface.
3. 3 - Cuts on County Route 519, NE of Hope, Warren Co., NJ (carbonate-pebble conglomerate (the Jacksonburg Limestone) at base of Tippecanoe Sequence, beneath the Jenny Jump thrust. [UTM Coordinates: 504.0E / 4529.3N, Blairstown quadrangle.] Exposed on L is limestone-pebble conglomerate at base of Tippecanoe Sequence (Jacksonburg Limestone in these parts; the rocks here are equivalent to the Balmville of the central Hudson Valley, New York). We have crossed the Jenny Jump thrust and these are the rocks below this fault.
4. 4 (Optional): Scenic Overlook, I-80, Columbia, NJ. [UTM Coordinates: N/A, Portland quadrangle.] Â We quote the following from the caption of a photograph taken from this spot (Epstein, 1980, fig. 4, p. 77): "...Kittatinny Mountain underlain by resistant quartzite and lesser siltstone and shale of the Shawangunk Formation. The Shawangunk generally dips moderately to the northwest, such as at Delaware Water Gap (2), but is overturned to the southeast in places. The dark laminated slates exposed along Interstate 80 below (3) are in the lower (Bushkill) member of the Martinsburg Formation. Paulins Kill Valley (4) is underlain by carbonate rocks of the Allentown Dolomite, Beekmantown Group, and Jacksonburg Limestone that are in a window and are separated from the Martisnburg by the Portland Fault. The hills in the middleground (sic) beyond the Paulins Kill (5) are underlain by the Bushkill and Ramseyburg Members of the Martinsburg Formation. The upper (Pen Argyl) Member of the Martinsburg first appears across the Delaware River in Pennsylvania, coming out from under the Taconic unconformity with the overlying Shawangunk Formation (6)..."
5. 5 - Northwest slope of Delaware Water Gap (Lower Silurian red quartzites and siltstones) under I-80 bridge. [UTM Coordinates: 488.4E / 4535.9N, Stroudsburg quadrangle.] The rocks exposed alongside I-80 consist of reddish sandstones, shales, and siltstones of the Silurian Bloomsburg Formation (equivalent to the High Falls Formation of previous On-The-Rocks trips). The sediments composing these rocks were deposited roughly 400 Ma (million years ago) in a broad deltaic fan complex; they are essentially non-fossiliferous excepting a few preserved remains of fish and plant fossils. The strata have been folded and display many aspects of cleavage. The features to see in the bedrock include gentle upright folds, inclined regional cleavage, and refracted cleavage. Before we leave this place, would you believe your eyes and that you can see glacial striae(!) parallel to the road (i.e., NW to SE)? These striae indicate that the Delaware Water Gap is as least as old as the last glacier from the NW. (Compare this situation with the lack of glacial striae in the Bronx River gorge.)
6. 6 - Cuts on PA Route 191, valley of Broadhead Creek, N of Stroudsburg, PA. [UTM Coordinates: 482.4E / 4541.8N, East Stroudsburg quadrangle.] Be prepared to make withdrawals from a Devonian bank (bioherm). Fossils are plentiful in the siltstone here. Where original skeletal calcite remains in the fresh rock, its color is white. The best collecting is in rust-colored pieces that are full of holes where the calcite has been dissolved away, leaving external- and/or internal molds. We found many bryozoa, corals, brachiopods, and champion critter collector CM found a coiled trilobite, pygidium and all. Novice collector Christopher (Vern) Merguerian made a fabulous brachiopod discovery on our pre-trip runthrough.
7. 7 - Cross-bedded Devonian sandstone cuts on PA 191, valley of Broadhead Creek, between Analomink and Henryville, N of Stroudsburg, PA. [UTM Coordinates: 480.6E / 4547.2N, East Stroudsburg quadrangle.] These sandstones, which prominently display large-scale cross strata, are probably equivalent to the Ashokan Flags of New York State. The cross strata imply that these are fluvial deposits. As such, they are the lowest of the thick Devonian strata that are mostly of nonmarine origin. The siltstones below are the youngest marine Devonian hereabouts.
8. 8 - Cuts on Cherry Valley Road, near boundary between Hamilton Township (Monroe Co.) and Stroud Township (Northampton Co.), S of Stroudsburg, PA. [UTM Coordinates: 480.3E / 4533.5N, Stroudsburg quadrangle.] These rocks are approximately equivalent to the New York "Manlius" Limestone. The polygons here have long been pointed out to geology students as examples of polygons formed by superimposed mudcracks. Yet, the dissolution residues along the sides of the polygons show that polygons have resulted from dissolution cleavage and are comparable to stylolites, the other geologic feature formed as a result of high pore pressure dissolution.
9. 9 - Resort Point Overlook, Stroudsburg, PA. [UTM Coordinates: 488.2E / 4536.2N, Stroudsburg quadrangle.] Get out of vans, fast! Scenic view. General discussion. The rocks in the large cuts directly opposite are the same rocks as at STOP 5. They show steep cleavage, refraction of cleavage, and thrust faults. We will not try to examine them here with a large group.
10. 10 - Cuts on PA 611, Point of Gap Overlook S of Stroudsburg, PA. [UTM Coordinates: 489.8E / 4535.9N, Portland quadrangle.] The rocks in the cut belong to the Lower Silurian Tuscarora Formation (equivalent of Shawangunk in New York). The strike is NE and the dip NW. Massive- to cross-stratified sandstone in layers 1 to 2 m thick are interbedded with slaty cleaved siltstones 5 cm to 0.5 m thick. The bases of some sandstones are channel fills; some beds pinch out; quartz pebbles are present in some beds. The talus slope on hillside on NE side of Delaware River covers the Martinsburg Formation.
11. 11 - Cuts on complex cloverleaf at junction of NJ 94, I-80, and US Route 46, Town of Columbia, NJ. [UTM Coordinates: 492.5E / 4530.5N, Portland quadrangle.] The complex of cuts in this cloverleaf complex expose Sauk Sequence carbonates (the Upper Cambrian Allentown Formation)in the Ackerman anticline that Drake (1978) and Drake and Lyttle (1980) infer form a part of the Paulins Kill window beneath the Portland thrust. We have not made a careful study of the contacts, but from the general relationships merely raise the question of whether or not this belt of carbonate rocks could be a klippe of a thrust sheet of older carbonates thrust above younger slates that possibly has been faulted down into the slates, as at Hope, rather than a folded overthrust of younger slates over older carbonates.

103 pages · Run: Saturday, 26 September 1992

Objectives

1. To discuss the topics: "What is a beach?" and what are smaller "Sons of Beaches".
2. To compare a narrow beach subject to chronic erosion with a wide beach subject to deposition.
3. To become familiar with the three sediment populations found at RMSP: a. well-sorted white medium sand; b. well-sorted dark-colored, esp. dark reddish, medium sand; and, c. poorly sorted coarse brown sand, gravel, and shell debris.
4. To recognize the various parts of an ocean beach, including the shore-parallel ridges of sand (are they dunes?), berm, beach face (and/or beach scarp), and the three morphodynamic zones of an ocean beach: supratidal, intertidal, and subtidal.
5. To study the relationship between deposition of new layers of sediment and sediment surfaces, including both small-scale bed forms and large-scale depositional "slopes;" and to recognize plane-, parallel-, and cross strata.
6. The understand the general geologic relationships of Long Island and the occurrence of ground water in various geologic units.
7. To be duly impressed by the evidence for the rapid westward growth of the west end of Fire Island as a result of inlet migration (average rate of 1 meter per week in the interval 1834-1940).
8. To realize how the effects of the operation of the geologic cycle through time create a geologic record of sediments and of sedimentary rock.

90 pages · Run: Saturday, 19 June 1993

Objectives

1. Study type sections of Stockton and Lockatong formations in the south-central part of the Newark Basin.
2. Observe facies changes between basin-marginal rudites and finer-textured strata away from the basin margin.
3. Examine evidence for lake-level control on sediments in the Lockatong Formation.
4. Study the effects of mid-Jurassic deformation, notably the evidence that significant strike-slip faults are present, and,
5. Try to avoid eating the hot dogs at Stop 5.

Field stops (3)

1. 3 - Conglomerate and interbedded sandstone in Solebury Member of Stockton Formation exposed in woods adjacent to the Stockton Borough School. [UTM Coordinates: 502.1E / 4472.5N, Stockton quadrangle.] Essentially monomict quartz-pebble rudites with intercalated coarse, cross-bedded sandstones are exposed at this locality. Marlene Leeb, Chief School Administrator, who was nice enough to permit access to this exposure, has asked us not to remove samples. Rounded, ellipsoidal pebbles of quartz (quartzite?) are up to 8 cm in long dimension in a matrix-supported conglomerate. Note the lack of carbonate clasts (compared with Stop 6, later today). The pebbles are aligned with their widest dimension lying flat within the layering of the enclosing sands with bedding. Large-scale cross beds are evident in the sandy matrix. Measurements of cross beds suggest a component of flow in the SW direction. Elsewhere channels at the base of the rudites are oriented NW.
2. 5 - Passaic Formation (formerly Brunswick Redbeds - only the name has changed, not the color!) [UTM Coordinates: 494.0E / 4488.5N, Frenchtown quadrangle.] Here, next to the dilapidated hot dog van, note red siltstones, very fine sandstones, and shale. The bedding surfaces are very gently dipping and display mudcracks, raindrop-impact pits, tiny ripples, and possible dinosaur tracks. Joints are spaced about a meter apart. Grab a hot dog, if you dare!
3. 6 - Basin-marginal rudites in Passaic Formation, S end of Gravel Hill. [UTM Coordinates: 488.5 E / 4491.5N, Riegelsville quadrangle.] Those of you who have been to Oakland, New Jersey, on our Palisades Newark Basin trip, will find this exposure looks somewhat familiar. Discrete layers containing rounded boulders of Paleozoic rocks, most of which are quartzites, but with the light-colored ones carbonates, are interbedded with layers composed of sand-size sediment. In some of the fine layers are scattered rounded boulders. According to Bradford Willard (1956), the limestones are fossiliferous Decker Limestone (Silurian?) and the quartzites are from the Green Pond Formation (Lower Silurian). This location is about 1 mile SE of the basin-marginal fault.

143 pages · Run: Sunday, 26 September 1993

Objectives

1. To show you some of the stratigraphic- and structural evidence upon which CM has proposed his far-reaching re-interpretation of the "Manhattan Schist."
2. To study features eroded on the bedrock by glaciers and try to convince participants that the dominant direction of glacier flow that can be reconstructed in Central Park is from NW to SE (from across the Hudson Valley) rather than from NNE to SSW (the direction of the most-recent glacier; which was down the Hudson Valley).
3. To become aware of all the improvements Robert Moses made to Central Park in 1934 and especially to follow Moses' first principle, namely that a visit to the Park should be the occasion for having a good time.

Field stops (11)

1. 1 - SE of Zoo work shed, Hartland formation and an obscene roche moutonée. [UTM Coordinates: 586.75E / 4513.10N, Central Park quadrangle.] The exposure consists of gray- and locally brown-weathering muscovite-biotite schist and thin interlayers of biotite granofels, rocks typical of the Hartland Formation (C-Oh) in New York City. The S2 foliation consists of parallel thin laminae and local syntectonic granitoid veins, predominates at this exposure. Abundant pegmatite veins (some with large books of muscovite) and veinlets create a nubby weathering appearance, but should not be confused with the aluminosilicate-induced nubby weathering of the C-Om unit of the Manhattan Schist. Evidence for SE-directed glacial flow is obvious in the glacially sculpted exposure in the form of large- and small grooves at the south end of the exposure. A fake roche moutonée is the product of drill-and-blast work of Obscene age (the period of geologic time stratigraphically above the Holocene) on the eastern edge of the exposure. Luckily, our glacial hypotheses are not drilled full of holes as the glacial grooves are real.
2. 2 - E of walkway just N of 65th Street Transverse Road; mylonitic Hartland formation cut by glacial grooves. [UTM Coordinates: 586.85E / 4513.32N, Central Park quadrangle.] The exposures of Hartland here consist of slabby, gray-weathering vitreous quartzite, granofels, minor schist and amphibolite with a laminated fabric developed parallel to a composite S2 foliation. S2, subparallel S1 and bedding (S0), are strongly transposed because of the effects of F3 Z-folds and associated lineations plunging SW. Vertical healed joints cut the exposures at a high angle and show positive relief producing a reticulate pattern with the dominant lithologic layering and subparallel metamorphic fabrics. All of the scattered outcrops show the effects of glacial rounding and -polish.
3. 3 - E of walkway near "X" crossing of paths S of "The Dene;" mylonitic Hartland formation and glacial grooves. [UTM Coordinates: 586.90E / 4513.40N, Central Park quadrangle.] Similar to the last exposure (still in view toward the S), here the Hartland possesses a pronounced mylonitic fabric suggesting that we are approaching Cameron's Line. The composite S2 + S3 foliation is transposed by F3 folding and has been intruded by numerous foliated lit-par-lit granitoids. In fact, two generations of granitoids cut the bedrock: 1) an older foliated generation, as mentioned above, and 2) a younger sinuous granitoid that cuts across the metamorphic layers. Glacial grooves are here products of a glacier that flowed SE.
4. 4 - Outcrop W of "The Dene"; two sets of cross-cutting glacial features on polydeformed Hartland formation. [UTM Coordinates: 586.83E / 4513.40N, Central Park quadrangle.] This large polished exposure contains rocks similar to the last three stops and shows the effects of superposed F2 and F3 folds. The composite S2 + S3 foliation is oriented NE and is vertical or dips steeply SE. We will examine the rocks for structural features on the trip day and concentrate here on glacial features. Obscured by post-glacial weathering on the E end of the exposure a partial pothole greets the observant student of geology. Nearby, glacial grooves are oriented NW again, supporting our earlier observations, indicating a SE-directed glacial ice-flow direction. At the NE end of the exposure a glacial treat awaits our eyes. Here, a subdued roche-moutonée structure oriented N37°E is cut by N36°W-trending glacial grooves. Thus, one of our older glacial advances has left its indelible mark on the bedrock.
5. 6 - At USGS bench mark S of The Pond; typical Hartland Formation away from the Cameron's Line thrust zone. [UTM Coordinates: 586.58E / 4512.93N, Central Park quadrangle.] Rocks of the Hartland Formation here consist of their typical gray-weathering, highly muscovitic schist and massive, structureless granofels in an exposure at the SE corner of "The Pond", across from the Plaza Hotel. The granofels layers are quite numerous; their thickness varies from 3 cm to 50 cm and they are separated by schistose layers, 3 cm to 4 cm thick, that are exceedingly rich in muscovite (only about 5% biotite). Muscovite-rich pegmatites locally have been intruded parallel to the S3 foliation. Near their contacts with the metamorphic strata one can find a veritable "library" of muscovite "books." Glacial grooves indicate SE-directed glacial-ice flow.
6. 7 - W of the Pond, opposite Avenue of the Americas access to Park; folded and glacially polished Hartland formation. [UTM Coordinates: 586.39E / 4513.05N, Central Park quadrangle.] Muscovite schist and interlayered granofels of the Hartland are cut by open warps of the composite S2 + S3 foliation. These folds, which must postdate the F3 folds, plunge southward with NE-trending axial surfaces. A minor shear zone in the center of the exposure cuts through a 10-cm-thick layer of amphibolite and an F2 reclined fold refolded by F3 occurs on the south end of the exposure. Glacial grooves are here oriented NW and a subdued roche moutonée structure is oriented NE. On our pre-trip visit, we were not able to establish any cross-cutting relationships. We observed SSW-oriented chattermarks on the northward-sloping surface of the roche moutonée.
7. 8 - On S side of West Drive, near SW boundary of Park; Hartland rocks sheared along F3 limbs and glacial features. [UTM Coordinates: 586.32E / 4513.04N, Central Park quadrangle.] The effects of shearing along the limbs of F3 folds here produce a penetrative foliation in highly muscovitic rocks of the Hartland Formation. The effects of rounding and smoothing of the bedrock surface here are quite obvious as are glacial grooves.
8. 9 - On N side of West Drive near bridge over walkway from 7th Avenue; Hartland rocks showing bedding. [UTM Coordinates: 586.27E / 4513.20N, Central Park quadrangle.] Pronounced interbedding of granofels and muscovite schist here typify the Hartland formation. We are near the vicinity of an F3 antiformal hinge area (CM's 7th Avenue Antiform). The F2 folds here show Z-fold symmetry indicating we are on the eastern side of the south-plunging antiform.
9. 11 - E side of walk E of Heckshcer Playground; pegmatite erratic on glacially polished Hartland rocks. [UTM Coordinates: 586.39E / 4513.38N, Central Park quadrangle.] The most-obvious feature of this stop is the 2m-high K-feldspar megacrystic pegmatite erratic. The erratic rests on rocks of the Hartland that have been scored by NW glacial grooves. F3 S-folds are locally found in the exposure.
10. 12 - E of junction of walks N of Stop 11; mildly mylonitic Hartland rocks. [UTM Coordinates: 586.39E / 4513.39N, Central Park quadrangle.] The Hartland Formation here shows some evidence for lithologic mixing; rocks of the "middle unit of the Manhattan formation," are present in the form of inclusions consisting of wisps- and shreds of aluminosilicate-bearing, rusty- to maroon-weathering schist. The outlines of the wisps and shreds are probably masked by shearing along S2 and S3 (a convenient circumstance that requires little leg-to-leg hopping by CM). F3 folds are not hard to spot with their typical southward plunges and steep NE-trending axial surfaces.
11. 13 - By the Carousel; the "middle unit" of the Manhattan Formation. [UTM Coordinates: 586.45E / 4513.43N, Central Park quadrangle.] The exposure of rocks immediately west of The Carousel show the rusty- to maroon-weathering typical of CM's "middle unit of the Manhattan Formation" (Unit C-Om). Layers- and lenses of kyanite+sillimanite+magnetite weather in positive relief and outline the S2 foliation which is largely mylonitic. CM maps this area as the beginning of the Cameron's Line thrust zone and links these exposures to those found at our earlier Stop 5. From here, after a brief interlude on The Carousel, we will begin a freeform mapping exercise to regions of the park north of Stop 13, hoping to further support our visions of the structural- and glacial history of the park. We plan to end somewhere near the American Museum of Natural History and then walk back to the Academy.

114 pages · Run: Sunday, 14 November 1993

Objectives

1. Evaluate the "shelving-basin" interpretation and the "transverse anticline" viewpoint.
2. Study an example of the Lockatong Formation that all previous workers evidently have overlooked.
3. Evaluate the significance of the curvature of the Palisades sheet in Rockland County, NY: is it a folded intrusive sheet or a steeply cross-cutting dike?
4. Briefly examine the pre-Newark rocks and the basal conglomeratic Newark strata near Stony Point State Park.
5. Look at the nearly horizontal strata in the Ladentown-Wesley Chapel area and try to figure out if they are anomalous with respect to the rest of the Newark strata in Rockland County, NY.
6. Compare weathered- with fresh rock in the Ramapo fault zone and record the orientations of the numerous fracture surfaces.

Field stops (2)

1. 3 - Newark Conglomerate, pre-Newark metamorphic- and igneous rocks, and west edge of Cortlandt intrusives at Stony Point State Park, Stony Point, NY. [UTM Coordinates: 585.62E / 4565.8N, Haverstraw quadrangle.] At this stop we make three small traverses at Stony Point State Park; one south of along the railroad cut to see conglomerate of the Newark Basin, one along the railroad cut that exposes intrusive rocks of the Stony Point-Cortlandt Complex and, a walk through the famous Stony Point battleground.
2. 4 - Vesicular- and amygdaloidal basalt of the Ladentown Basalt of Kummel (1900) on Limekiln Road. [UTM Coordinates: 576.3E / 4557.1N, Theills quadrangle.] When construction was underway for these houses, pillowed basalt was exposed at the top of the knoll. We'll discuss the geologic relationships inferred by Ratcliffe (1988) in connection with the Spook Rock core site.

113 pages · Run: Saturday, 27 April 1996

Objectives

1. To study the basal contact of the New Haven Arkose and the kinds of metamorphic rocks forming the floor of the Hartford Basin.
2. To examine paleosol caliche in the New Haven Arkose and study the contact-metamorphic effects on the caliche along the walls of mafic dikes.
3. To examine pillows--the products of the extrusion of hot lava under a cover of water.
4. To examine the characteristics of the Newark sedimentary strata and to notice the contrast between sediments deposited well away from the basin-marginal fault along the SE basin margin and those deposited close to this basin-marginal fault.
5. To study the composition of boulders in the basin-marginal rudites (general name for any coarse sediment composed chiefly of gravel-size debris, i. e., coarser than 2 mm).
6. To study the evidence for postdepositional faults and the relationship between some of these faults and gaps in Saltonstall Ridge.
7. To examine the evidence for the presence of the Talcott Formation along the basin-marginal fault and to observe a distinctive volcanic breccia.
8. To visit the Eastern Uplands and examine the pink granitic rocks at Stony Creek and the light gray granitic rocks at Lighthouse Point.

Field stops (10)

1. 1 - Base of Newark Supergroup in contact with Milford Chlorite Schist, Amity Shopping Center. [UTM Coordinates: 668.55E / 4577.83N, New Haven quadrangle.] You're on your own.
2. 2 - New Haven Arkose and caliche carbonate (green) cut on Wilbur Cross Parkway at Interchange 60. [UTM Coordinates: 673.81E / 4581.02N, New Haven quadrangle.] Krynine (1950) measured a section here when the cut on the Parkway was fresh. In 1958, JES spotted the green calcareous nodules and interpreted them as probable caliche. Hubert (1977, 1978) has published the results of his careful petrographic examination of the caliche/calcrete. We will forego an opportunity to see spectacular exposure of caliche carbonates, etc., in the New Haven Arkose on Mt. Carmel Connector Road. Pedogenic carbonates are important indicators of a former semiarid climate.
3. 3 - New Haven Arkose in contact with N wall of Mill Rock dike. [UTM Coordinates: 674.35E / 4578.07N, New Haven quadrangle.] You're on your own.
4. 4 - Top of East Rock. On a clear day, the view from up here is spectacular. [UTM Coordinates: 675.19E / 4577.09N, New Haven quadrangle.] You're on your own.
5. 5 - New Haven Arkose in contact with one of the Foxon dikes. [UTM Coordinates: 678.07E / 4576.29N, Branford quadrangle.] You're on your own.
6. 6 - Pillowed Talcott basalt, hillside E of what formerly was the Weeping Willows Restaurant, E of Laurel Street, East Haven. [UTM Coordinates: 678.11E / 4574.60N, Branford quadrangle.] At this locality, the distance from the basin-marginal fault is 2 miles. (3.2 km). The strata strike NE and dip gently SE on a limb of the Saltonstall syncline. The part of the Talcott exposed here is the base of the pillowed- and brecciated member. The correct classification of the underlying pebbly coarse sandstone is still a puzzle. The answer depends on whether other Talcott flow units are present below the sandstone. If so, then these strata belong in the middle sedimentary member. If not, then these strata presumably belong at the top of the New Haven Arkose. The effect of a Pleistocene glacier on the pebbly sandstone is also well displayed here. This is a good spot for comparing the scratches and striae created by a glacier with the marks made by the large power shovel used in excavating the till.
7. 7A - Cut on N side of US Route 1, East Haven, at junction with western end of loop made by CT Route 142. This is the southern of two large gaps in Saltonstall Ridge. [UTM Coordinates: 679.10E / 4571.51N, Branford quadrangle.] A tape-and-compass traverse of this cut in the Shuttle Meadow indicates that about 190 ft of strata are present; there are numerous small faults, but nevertheless the succession seems to be fairly straightforward. The lower 80 ft are interbedded sandstone and siltstone with a few pebbly layers. Two prominent conglomerates are present: a unit 20 ft thick at 80 ft above the base of the exposure, and a unit 18 ft thick at 130 ft above base of the exposure. The sandstones at the top of the exposure may correlate with those exposed north of the New Haven Railway tracks in the next gap to the north, but this is not certain.
8. 7B - Cuts on AMTRAK Railway and Connecticut Turnpike, East Haven, in an artificial gap west of Saltonstall Lake, the northernmost of the two large gaps in Saltonstall Ridge. [UTM Coordinates: 679.06E / 4571.95N, Branford quadrangle.] To begin with, the Shuttle Meadow strata in the railway cut consist largely of sandstone and siltstone in beds 1 to 3 ft thick; a tape-and-compass traverse indicates 174 feet of strata are present from the bridge abutment on the north side of the tracks to the western limit of the exposure. The contact between Shuttle Meadow sandstone and Holyoke basalt was exposed during construction of the bridge in the middle of the nineteenth century; the stones of the bridge pier conceal it now. The top of the Holyoke is present just east of this bridge, on both the N side and S side of the tracks. The horizontal distance between the base of the Holyoke and the top of the sheet is 110 ft; assuming a dip of 45° this indicates a vertical component of slip equal to about 700 ft. About 1 ft above the base of the overlying East Berlin Formation is a limestone bed 1 ft thick; it is visible in the cut on the south side of the railway and east of the bridge.
9. 9 - Proterozoic Stony Creek Granite at Stony Creek, remobilization rather than classical intrusion? [UTM Coordinates: ~688.25E / 4570.82N, Branford quadrangle.] You're on your own.
10. 10 - Lighthouse granite-gneiss, Lighthouse Point Park, New Haven, CT. [UTM Coordinates of BM @ +31': 675.75E / 4568.52, Branford quadrangle.] You're on your own.

148 pages

165 pages · Run: Sunday, 14 September 1997

Field stops (4)

1. 2 - Pillow basalt of Orange Mountain Formation ("First Watchung Basalt"). East side of McBride Avenue ~0.7 mile NE of intersection of Glover Avenue and McBride Avenue. [UTM Coordinates: 568.1E / 4528.9N, Paterson quadrangle.] The McBride Avenue exposures are about in the middle of the outcrop belt of the Orange Mountain Formation here. Geologists exploring the sea floor in research submarines been photographed modern pillows forming where lava oozing out of a fissure reacts with the water in such a way that individual pillows are squeezed out, expand, and then separate. The large pillowed part of the Orange Mountain Formation is inferred to have resulted from the extrusion of lava on the bottom of a large lake.
2. 3 - Lower contact of the Orange Mountain Formation ("First Watchung Basalt") and underlying sedimentary strata of the Passaic Formation. [UTM Coordinates: 569.00E / 4529.45N, Paterson quadrangle.] In the low cuts in the parking lot one can see the contact between an overlying mafic extrusive igneous rock (Orange Mountain Formation) and a sedimentary rock (top of Passaic Formation). The contact is not a planar surface but displays considerable irregularity. The direction of in which a sheet of ancient lava flowed can be determined from cylindrical (="pipe") vesicles and -amygdales. Typically these are bent over in the direction toward which the lava flowed. According to Manspeizer (1980), pipe amgydales here are bent over toward the NE. (See Figure 38.) This is the opposite to the direction inferred for the paleoslope of the land surface (based on directions of flow of streams that deposited the cross strata). As a result, the lava here onlapped the regional paleoslope.
3. 4 - The Great Falls of Paterson, Orange Mountain and Passaic formations. [UTM Coordinates: 568.9E / 4529.5N, hillside exposures E and N of stadium: 569.05E / 4529.75N for contact and 569.15E / 4529.85N for cliff face near dog pound, glacial erratic at 568.95E / 4529.65 N, Paterson quadrangle.] The waterfall here drops about 75 feet (from the 120-ft contour at the lip to about 45 ft below). The Passaic River, flowing northeastward (more or less parallel to the strike of the tilted strata), pours into a fracture that trends N-S. The water tumbles over the lip on the rock forming the W side of the fracture, and then flows southward along the fracture, then makes a U-turn and continues flowing NE. No gorge has formed downstream, as has been eroded, for example, by the upstream retreat of the lip of Niagara Falls. In its flow along a fracture and absence of a gorge, Great Falls are a miniature version of the mighty Victoria Falls on the Zambezi River in southeastern Africa (Zambia/Zimbabwe). This stop includes a walk northward beyond the falls to examine sandstones of the Passaic Formation and a large glacial erratic.
4. 5 - Upper, glaciated contact of the Orange Mountain Formation ("First Watchung basalt") at Garrett Mountain Reservation. [UTM Coordinates of old house: 569.50E / 4577.75N, Paterson quadrangle, altitude: 500 feet.] From the crest of the ridge enjoy the splendid view eastward toward Manhattan (atmospheric conditions permitting). Notice the two clusters of skyscrapers: at the Battery and in midtown Manhattan. This is a function of the depth of bedrock. Where the tall buildings have been built, solid bedrock is close to the surface. In between, where no tall buildings have been built, the depth to bedrock becomes several hundred feet. Along the trail, look for vesicles in the basalt (we are near the top of a flow unit where vesicles are to be expected) and the glacial features. Present here are glacial grooves trending NE-SW, about parallel to the trend of Garrett Mountain, and a miniature roche moutonée structure.