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+[http://ntpckoldam.nic.in/dt/p3.htm/ Start of tunneling with Boomer] HOFSTRA
+UNIVERSITY 1C FIELD GUIDEBOOK A GEOLOGICAL TRANSECT FROM NEW YORK CITY TO NEW
+JERSEY Physiographic block diagram of northern Manhattan, the Bronx, the Hudson
+River and New Jersey showing the generalized structural geology of the region.
+(Drawing by A. K. Lobeck, Columbia University.) Field Trip Notes by Professor
+Charles Merguerian © 2002 HOFSTRA UNIVERSITY Department of Geology Hempstead,
+NY 11549 Core Course 01C Physical Geological Science Geology Field Trip
+Guidebook By: Charles Merguerian INTRODUCTION Welcome to Hofstra's "Geology
+Express", an all-day geo-excursion designed to introduce you to the "real
+world" of how geologists work in the great out-of-doors, or in their terms, "in
+the field." You are going to see for yourself many of the features that you
+have been reading about or hearing about in Geology 1C to date plus some
+features that you will be learning about later in the semester. This trip will
+take you back in time across terranes that formed as recently as 10,000 years
+ago, and past those that formed over a billion years ago! All of your favorite
+Professors from the Geology Department are aboard the geo-excursion buses ready
+to discuss the geological explanations of features visible out your windows and
+in the field. They will also serve as your guides and will be available to
+field questions (yes, dear friends, pun intended!). So sit back and relax. To
+get the most from your day, be sure to read this guidebook while we are riding
+in the bus – rest rooms and reading sickness bags have been provided! The
+guidebook will explain where you are and where you're going. Participate in the
+discussions. Ask questions. And, of course, take pictures. In order to maintain
+a sense of scale, geologists commonly place a ruler or a well-known object in
+the corner of a photogenic area. (For example, a pen, hammer, coin, B-1 bomber,
+etc.) Remember, you must produce a photo essay to illustrate twenty different
+rocks, structures, or products of geologic processes as seen at the field-trip
+stops. Advanced geology students may be on the trip and will help you, along
+with your lab and lecture professors, to identify geologically interesting
+photo opportunities. The guidebook you hold in your hands will help in
+formulating your captions and detailed instructions on the format and
+preparation of your photo essay are available from your laboratory professor or
+instructor. The foremost point to keep in mind today is James Hutton's concept
+of the "Great Geological Cycle" -- how the operations of the natural processes
+going on around us create a geologic record and how geologists can look at the
+geologic record and work backward to figure out what happened. In this scheme
+of working backward from the geologic record into geologic history, geologists
+operate in a totally different way from experimental scientists, such as
+chemists, for example. In an experimental science, the investigator tries to
+control the conditions as carefully as possible in order to relate condition to
+the result. A geologist usually is faced with the result (the geologic record)
+and is asked, in effect, to figure out what experiment took place. The geologic
+record consists of three components that exist in three dimensions: (1) the
+bedrock, (2) the regolith, and (3) the physiography of the Earth's surface.
+Geologists commonly use two-dimensional maps and diagrams to illustrate the
+three dimensions of study and will invoke a fourth dimension into the equation
+- namely time. That is, we are concerned with the developmental history of a
+geologic terrain over the broad expanse of time. In the following introductory
+paragraphs, we review each of these components and show how they are connected.
+GEOLOGICAL BACKGROUND Bedrock To the casual observer, bedrock is known as the
+place that the Flintstones and Rubbles live. Bedrock, to geologists, means the
+continuous solid crustal rock of a continent that exists everywhere, either
+exposed at the Earth's surface or occurs buried by loose "dirt" or "alluvium"
+("soil" to the engineers). The unconsolidated material that covers the bedrock
+is collectively designated as the regolith. Bedrock has to be dealt with using
+hammers and hand lenses. By contrast, one uses a shovel to do business with the
+regolith. Bedrock is a collective designation that includes igneous,
+sedimentary, or metamorphic rocks. On Long Island, bedrock exposures are
+extremely scarce. A few examples are known near the Queens County Courthouse,
+and in Long Island City, at the extreme western edge of the island. In
+Manhattan, the Bronx, and Staten Island bedrock is exposed at the surface in
+scattered rocky knolls known as outcrops. Elsewhere, the bedrock has been
+buried by sandy regolith to depths of hundreds of meters. The ancient
+metamorphic and igneous rocks of the continents are largely covered by a veneer
+sedimentary rock. In areas where no natural outcrops exist, regolith covers the
+bedrock sequence. Because we want to show you some different kinds of bedrock
+and regolith, we must travel off Long Island to the Bronx and to northern New
+Jersey. (See figure on cover.) Let us begin by discussing some basic geological
+aspects of sedimentary strata. Regolith The regolith collectively designates
+the loose, diggable material that overlies the bedrock. The upper part of the
+regolith may have an organic component and be capable of supporting plant
+growth. If so, then this upper part is known as a soil. Regolith forms from
+bedrock or from lava being extruded from a volcano. Some regolith forms by the
+weathering of bedrock (a slow process). Other regolith is the product of
+several fast-acting processes by which bedrock can be broken to bits quickly,
+so to speak. The bedrock forming steep rocky cliffs may cascade downward
+rapidly in a rock avalanche. A product of such an avalanche is a local body of
+regolith. The impact of an extraterrestrial object such as a meteorite may
+create regolith, known as ejecta. Beneath a glacier bedrock is ground into
+regolith. For those who cannot wait for geologic time to do its thing, during
+certain kinds of volcanic activity vast quantities of "instant" new regolith
+are created by explosions (which may involve new igneous rocks in their
+formative stages or old rocks through which the magma passes on its way to the
+surface). Because of its enormous surface area and glass content, volcanic
+regolith can be converted to soil very rapidly. Much volcanic regolith is
+propelled high into the atmosphere and is responsible for beautiful sunsets. An
+important point to be determined about regolith is whether it is forming by
+weathering of the underlying bedrock (= residual regolith) or whether it is
+unlike the underlying bedrock and thus has been moved in from some other place
+(transported regolith). Two common processes by which transported regolith is
+brought into an area are: (1) glaciers, and (2) the wind. Physiography of the
+Earth’s Surface The Earth's landscape has been fashioned by the operation of
+many distinctive processes that we shall be studying in the next few weeks.
+Examples are valleys carved by streams, beaches built by waves, intertidal salt
+marshes growing at the edge of the sea, dunes blown by the wind, ridges heaped
+up by glaciers, various features eroded by glaciers, deltas built at the mouths
+of rivers, and the general shapes of the hills and valleys as a result of the
+general process of erosion. Your instructor will explain the origin of any
+distinctive surface features that we encounter. Regions within which the
+bedrock or the regolith display distinctive landscapes are known as
+physiographic provinces. In summary, the three components of the geologic
+record are: (1) the bedrock, (2) the regolith, and (3) the physiography or
+“shape” of the Earth's surface. All are connected by the operation of the
+rock cycle by which rocks that form beneath the Earth's surface are rearranged
+at the Earth's surface and then may be still further changed by being buried
+again to great depths. Our objectives are to be able to identify the features
+found in the bedrock, to determine if any regolith is residual or transported,
+and to understand distinctive surficial features. This field trip guidebook is
+arranged to discuss the geologic scenery of driving segments (called legs) and
+descriptions of the three sites (called stops) that you will examine in detail.
+Through the aid of sketches, drawings, index maps, geologic maps and
+cross-sections (collectively called figures in the text), you can follow your
+field trip along each step of the way and gain some insight into identifying
+what is “important” in this world of Geology. Most of the detailed stop
+descriptions and tables provided herein are excerpted from field-trip guides
+written by Merguerian and Sanders in the interval 1988 to 1998 and from more
+contemporary research. An important point to be gained from this trip is
+familiarity with some parts of the geologic time scale. To help you with this,
+we have included Table 1, a geological time scale that should be consulted
+while reading the following discussion. We will introduce a given geologic
+feature by referring to its age in years, but then will shift to the
+corresponding term from the geologic time scale. Table 2 is a generalized
+description of the major geologic "layers" (described below) found in
+southeastern New York State and vicinity. Table 3 provides a stratigraphic
+classification of the Pleistocene deposits of New York City and vicinity. Now,
+for you, a brief geological primer to give you some instant insights into the
+world of geology. A BRIEF GEOLOGICAL PRIMER Stratification In dealing with the
+geologic structures in sedimentary rocks, the first surface one tries to
+identify positively is bedding or stratification. The boundaries of strata mark
+original sub-horizontal surfaces imparted to sediment in the earliest stage of
+the formation of sedimentary rock. As such, strata represent sequences of time.
+Imagine how such strata, buried by the weight of overlying strata are
+compressed and lithified to produce sedimentary rocks. If they are subject to
+compressive forces generated by the advance of convergent lithospheric plates,
+differential force necessary for rock deformation (folds and faults) can occur.
+Contrary to older ideas, we now realize that vertical burial cannot cause
+regional folds (although small-scale slumping, stratal disharmony, and clastic
+dikes are possible). Rather, resolved differential stress must be applied to
+provide the driving force to bring about deformation (folds and faults).
+Surfaces of Unconformity Surfaces of unconformity mark temporal gaps in the
+geologic record and commonly result from periods of uplift and erosion. Such
+uplift and erosion is commonly caused during the terminal phase of regional
+mountain-building episodes. As correctly interpreted by James Hutton at the
+now-famous surface of unconformity exposed in the cliff face of the River Jed
+(Figure 1), such surfaces represent mysterious intervals of geologic time where
+the local evidence contains no clues as to what went on! Usually, they mark
+periods of tectonism, uplift, and erosion produced during mountain building in
+adjacent areas. Thus, by looking elsewhere, the effects of a surface of
+unconformity of regional extent can be recognized and piecemeal discovery of
+evidence for filling in the missing interval may be found. Unconformities occur
+in three basic varieties - angular unconformities, nonconformities, and
+disconformities. Angular unconformities (such as the River Jed) truncate
+dipping strata below the surface of unconformity and thus exhibit angular
+discordance at the erosion surface. Nonconformities separate sedimentary strata
+above the erosion surface from eroded igneous- or metamorphic rocks below.
+Disconformities are the most-subtle variety, separating subparallel sedimentary
+strata. They are commonly identified by paleontologic means, by the presence of
+channels cut into the underlying strata, or by clasts of the underlying strata
+in their basal part. The strata above a surface of unconformity may or may not
+include clasts of the underlying strata in the form of a coarse-grained, often
+bouldery basal facies. During today’s trip we will see many different types
+of unconformities in the field. For example, as we drive across the Hudson
+River later in the day we travel across a nonconformity, with tilted
+sedimentary rocks of the Newark Basin resting unconformably upon metamorphic
+rocks of the Manhattan Prong. (See cover figure.) In this case the unconformity
+is tilted westward along with the overlying Newark strata. Following the
+proposal made in 1963 by L. L. Sloss, surfaces of unconformity of regional
+extent within a craton are used as boundaries to define Stratigraphic
+Sequences. It's now time to turn to some geometric aspects of the features
+formed as a result of deformation of rocks in the Earth. We start with folds.
+Figure 1 - Unconformity with basal conglomerate along the River Jed, south of
+Edinburgh, Scotland. From James Hutton's "Theory of the Earth", (1795). Folds
+The layers present in bedrock may be horizontal, vertical, or disposed at some
+intermediate angle. An important goal of many geologic field investigations is
+to work out the arrangement of the layers and to determine the geologic
+structure of a region. A widespread kind of geologic structural feature is a
+fold, defined as a bend in the layers. When rocks bend, they are behaving in a
+condition defined as ductile (as contrasted with brittle). We have not yet
+discussed folds in class, but we need to know some things about them. At
+Orchard Beach (Stop 1), for example, it is impossible to find any bedrock that
+has not been folded. When subjected to differential forces, under high
+confining pressures and elevated temperatures, rocks (like humans) begin to
+behave foolishly, squirming in many directions and upsetting the original
+orientation of primary- or secondary planar- and linear features within them.
+New planar and linear fabrics develop in the rock mass. Geologists try to sort
+out the effects of deformation by working out the relative order in which these
+structural surfaces or linear features formed. In dealing with the structural
+geology of sedimentary rocks, the first surface to positively identify is
+bedding or stratification. At crustal levels below 10 km folds and faults are
+accompanied by recrystallization and reorientation of newly formed metamorphic
+minerals. More on metamorphic textures below - for now let's discuss some
+geometric aspects of structural geology. If layers are folded into convex
+upward forms we call them anticlines. Convex-downward fold forms are called
+synclines. In Figure 2, note the geometric relationship of anticlines and
+synclines. In eroded anticlines, strata forming the limbs of the fold dip away
+from the central hinge area or axis of the structure. In synclines, the layers
+forming the limbs dip toward the hinge area. As such, older stratigraphic
+layers are expected to peek through in the axes of eroded anticlines but
+younger strata are preserved in the eroded axes of synclines. In metamorphic
+terranes, field geologists are not always sure of the stratigraphic topping
+direction of the metamorphosed strata. Thus, we tend to use the terms
+"antiform" and "synform" which describe the shapes of folds but do not imply
+anything about the relatative ages of the strata. Axial surfaces of folds
+physically divide the fold in half. Note that in Figure 2, some folds are
+deformed about a vertical axial surface and are cylindrical about a linear fold
+axis that lies within the axial surface. The locus of points connected through
+the domain of maximum curvature of the bedding (or any other folded surface of
+the fold) is known as the hinge line (which is typically parallel to the fold
+axis). This is geometry folks and we have to keep it simple so that geologists
+can understand it. Realize that in the upright folds shown in Figure 2, axial
+surfaces are vertical and fold axes, horizontal. Keep in mind that folding
+under metamorphic conditions commonly produces a penetrative mineral fabric
+with neocrystallized minerals (typically micas and amphiboles in matrix of
+recrystallized quartz and feldspar) aligned parallel to the axial surfaces of
+folds. Such metamorphic fabrics are called foliation, if primary, and
+schistosity, if secondary. Minerals can also align in a linear fashion
+producing a metamorphic lineation. Such features can be useful in interpreting
+a unique direction of tectonic transport or flow direction in ductile rock
+masses. Because folds in metamorphic rocks are commonly isoclinal (high
+amplitude to wavelength aspect ratio) with limbs generally parallel to axial
+surfaces, a penetrative foliation produced during regional dynamothermal
+metamorphism will generally parallel the reoriented remnants of stratification
+(except of course in the hinge area of folds). Thus, a composite foliation +
+remnant compositional layering is commonly observed in the field. Departures
+from this common norm are important to identify as they mark regional fold
+hinge areas. Folds could care less about the orientation of their axes or axial
+surfaces and you can certainly imagine tilting of the axial surface, to form
+inclined or overturned folds, or a sub-horizontal axial surface, to form
+recumbent folds, all accomplished by keeping the fold axis sub-horizontal
+(Figure 2). In addition, we can keep the axial surface vertical and alter the
+plunge of the axis from horizontal to some angle other than 0° to produce a
+plunging fold. Such folds can be plunging anticlines (antiforms) or plunging
+synclines (synforms). Vertical folds (plunging 90°) also occur, in which case
+the terms anticline and syncline are not meaningful. Most folds in complexly
+deformed mountain ranges show the effects of more than one episode of
+deformation and as such their ultimate configuration can be quite complex
+(i.e., plunging folds with inclined axial surfaces and overturned limbs).
+Figure 2 - Composite diagram from many introductory texts showing various fold
+styles and nomenclature as discussed in the text. Depending upon the direction
+in which the rocks were being transported when the folds formed, one of three
+categories of folds may come into being. These three categories of folds are
+named from the letters of the English alphabet that they resemble: S, M, and Z.
+As soon as you spot a fold, study it to find out if it belongs to the S
+category, the M category, or to the Z category. Typically, fold categories run
+in packs and the place where the folds of the S pack change over to those of
+the Z pack (or vice versa) is along the median line (axial surface) of a larger
+fold where M-folds develop. Structural geologists use a relative nomenclature
+to discuss superimposed episodes of deformation (Dn), folding (Fn), foliation
+(Sn), and metamorphism (Mn), where n is a whole number starting with 1. Bedding
+is commonly designated as S0 (or surface number zero) as it is commonly
+overprinted by S1 (the first foliation). To use this relative nomenclature to
+describe the structural geology of an area, for example... "during the second
+deformation (D2), F2 folds formed with the development of an axial planar S2
+schistosity under progressive M1 metamorphic conditions”. One final note on
+folding -- it is generally agreed, in geologically simple areas, that axial
+surfaces form perpendicular to the main stress (force) that produced the fold.
+Therefore, the orientation of regional fold axial surfaces gives some hint as
+to the direction of application of the active forces (often a regional
+indicator of relative lithospheric plate convergence). In complex regions, the
+final regional orientation of the structures is a composite result of many
+protracted pulses of deformation, each with its unique geometric attributes.
+Faults A fault is defined as a fracture along which the opposite sides have
+been displaced. The surface of displacement is known as the fault plane (or
+fault surface). The enormous forces released during earthquakes produce
+elongate gouges within the fault surface called slickensides. They may possess
+asymmetric linear ridges that enable one to determine the relative motion
+between the moving sides (Figure 3, inset). The block situated below the fault
+plane is called the footwall block and the block situated above the fault
+plane, the hanging-wall block. Extensional force causes the hanging-wall block
+to slide down the fault plane producing a normal fault. [See Figure 3 (a).]
+Compressive forces drive the hanging-wall block up the fault plane to make a
+reverse fault. A reverse fault with a low angle (&lt;30°) is called a thrust
+fault. [See Figure 3 (b).] In all of these cases, the slickensides on the fault
+will be oriented more or less down the dip of the fault plane and the
+relationship between the tiny "risers" that are perpendicular to the striae
+make it possible to determine the relative sense of motion along the fault.
+Experimental- and field evidence indicate that the asymmetry of slickensides is
+not always an ironcled indicator of relative fault motion. As such, displaced
+geological marker beds or veins are necessary to verify relative offset. Fault
+motion up- or down the dip (as in normal faults, reverse faults, or thrusts
+faults) is named dip-slip motion. Rather than simply extending or compressing a
+rock, imagine that the block of rock is sheared along its sides (i. e., that
+is, one attempts to rotate the block about a vertical axis but does not allow
+the block to rotate). This situation is referred to as a shearing couple and
+could generate a strike-slip fault. [See Figure 3 (c).] On a strike-slip-fault
+plane, slickensides are oriented subhorizontally and again may provide
+information as to which direction the blocks athwart the fault surface moved.
+Figure 3 - The three main types of faults shown in schematic blocks. Along a
+normal fault (a) the hanging-wall block has moved relatively downward. On a
+thrust fault (or reverse fault) (b) the hanging-wall block has moved relatively
+upward. Along a strike-slip fault (c), the vertical reference layer (black) has
+been offset by horizontal movement (left-lateral offset shown here). Inset (d)
+shows segments of two blocks along a slickensided surface show how the jagged
+"risers" of the stairsteps (formed as pull-apart tensional fractures) can be
+used to infer sense of relative motion. [(a), (b), (c), Composite diagram from
+introductory texts. (Inset from J. E. Sanders, 1981, fig. 16.11 (b), p. 397.)
+Two basic kinds of shearing couples and/or strike-slip motion are possible:
+left lateral and right lateral. These are defined as follows. Imagine standing
+on one of the fault blocks and looking across the fault plane to the other
+block. If the block across the fault from you appears to have moved to the
+left, the fault is left lateral [illustrated in Figure 3 (c)]. If the block
+across the fault appears to have moved to the right, the motion is right
+lateral. Convince yourself that no matter from which block you can choose to
+observe the fault, you will get the same result! Naturally, complex faults show
+movements that can show components of dip-slip- and strike-slip motion,
+rotation about axes perpendicular to the fault plane, or reactivation in a
+number of contrasting directions or variety. This, however, is no fault of
+ours. Tensional- or compressional faulting resulting from brittle deformation,
+at crustal levels above 10 to 15 km, is accompanied by seismicicity and the
+development of highly crushed and granulated rocks called cataclasites
+(including fault gouge, fault breccia, and others). Begining at roughly 10 to
+15 km and continuing downward, rocks under stress behave aseismically and
+relieve strain by recrystallization and internal flow. These unique metamorphic
+conditions prompt the development of highly strained (ribboned) quartz,
+feldspar porphyroclasts (augen), and frayed micas and results in highly
+laminated ductile-fault rocks called mylonites. The identification of such
+ductile fault rocks in complexly deformed terranes can be accomplished only by
+detailed mapping of metamorphic lithologies and establishing their geometric
+relationship to suspected mylonite zones. Unfortunately, continued deformation
+under load often causes early formed mylonites to recrystallize and thus to
+produce annealed mylonitic textures (Merguerian, 1988), which can easily be
+"missed" in the field without careful microscopic analysis. Cameron's Line, is
+an original ductile fault zone (mylonite) having a complex geologic history
+that includes recrystallization and post-tectonic brittle reactivation. Joints
+Although we have defined bedrock as being "continuous" and "solid," in reality
+it may consist of various layers and display several kinds of cracks (syn.:
+fractures where it has been broken) or partings, which are surfaces between
+layers along which blocks of the rock can separate. Along the cracks, the
+facing sides may or may not have been displaced. A fracture along which the
+adjacent blocks have not been displaced is known as a joint. The existence of
+joints is a signal that the rock behaved in response to deformation or,
+perhaps, simple unloading, as a brittle solid. A fracture along which the
+adjacent blocks have been displaced is known as a fault. Joints rarely exist in
+isolation. Typically they form a group of parallel fractures known as joint
+sets. Several joint sets may intersect in such a manner as to break the solid
+bedrock into many large blocks, each ending at a joint. Many joint faces are
+simply planar surfaces that display the fresh bedrock. Other joint faces have
+been coated with one or more mineral linings. Pyrite is a common deposit on
+joint faces. The proof that pyrite lines some joint faces comes from deep
+borings in quarries and holes drilled for other purposes. The rocks from these
+borings are fresh; the samples come from depths where conditions have excluded
+rainwater. When it is brought close to the Earth's surface and into contact
+with oxygen-bearing rainwater, pyrite (a sulfide mineral) decomposes readily.
+The iron from the pyrite is oxidized and the yellow-tan mineral limonite and/or
+its reddish cohort, hematite forms during chemical weathering. The sulfur from
+the pyrite is oxidized and combines with water to form sulfuric acid. Other
+minerals commonly found on joint faces include calcite, quartz, and chlorite (a
+green mineral of the mica group). The minerals that grow along the joint faces
+may fill the formerly empty space. If they do this, they form a tabular mineral
+deposit known as a vein. In their shapes, many veins resemble dikes, which you
+may recall are discordant tabular plutons - bodies of igneous rock. The
+difference between a vein and a dike reflects the mode of growth of the
+crystals. In a vein, the minerals grew outward from a solid-rock face into an
+opening toward the center. In a dike, the magma wedged itself into the crack
+and the minerals forming the igneous rock crystallized from countless nucleii
+scattered throughout the magma. Joints are the perfect locii for physical and
+chemical weathering to occur. During a rainstorm, rainwater seeps into the
+openings along joints. The seeped-in water evaporates very slowly; thus, it
+persists between rain showers. The water stored in the openings found along
+joints can be used as a solvent for chemically active fluids and by tree roots.
+The initial roots that grow downward along a joint may be tiny, hairlike
+features that can insert themselves into the most minute cracks. With time,
+however, the sizes of the roots enlarge. Eventually, the roots may pry loose
+large blocks that are bounded by joints. See if you can spot any examples of
+tree roots growing along joints. GEOLOGY (SIMPLIFIED) OF THE FIELD TRIP ROUTE
+We start by examining the shape of the Earth's surface in the region we plan to
+visit. Figure 4 is an oblique bird's eye view of the territory included on our
+field trip. The diagram, drawn to emphasize the contrasts in physiographic
+characteristics, has numbers of our intended Stops 1 through 3 shown. Because
+the group is so large, half of the buses will go first to Stop 1 and the other
+half to Stop 2. Those in the first group will proceed in the order 1, 2, and
+then 3. Those in the second group will proceed in the order 2, 3, and 1. We
+hope that you can adjust to the relative order of your field trip route by
+flipping to the appropriate pages in this guide. If this is confusing to you,
+we then suggest you take two weeks off from Hofstra – then quit. The first
+driving leg of your journey will take you across a number of distinctive
+geologic belts (called physiographic provinces) that are roughly oriented
+northeasterly, parallel to the main trend of the Appalachian mountain belt. We
+will travel from the buried coastal plain of Long Island across the Manhattan
+Prong of New York City to the Newark basin of New Jersey. In doing so we will
+cross major unconformities and former plate boundaries. The major geologic
+layers on this part of the Appalachian mountain belt are listed, from oldest
+[Layer I] to youngest [Layer VII] in Table 2 and shown in Figure 4. For ease of
+discussion, we describe the major geological layers found in the area of your
+field trip from the top down (meaning from youngest to oldest). Figure 4 -
+Physiographic diagram of northern New Jersey and adjacent regions of New York
+with cut-away vertical slice to show geologic structure. Note positions of our
+field-trip Stops (1, 2, and 3). Drawing by A. K. Lobeck, Columbia University.
+LAYER VII - THE GLACIAL STRATA OF LONG ISLAND Long Island is capped by a thin
+veneer of Pleistocene sediment [Layer VII in Table 2] ranging in age from
+10,000 years old to possibly much older (perhaps 200,000 years ago). The
+glacial sediment is collectively called drift but consists of till and outwash.
+It is not unusual to find large exotic boulders (called erratics) in Long
+Island's glacial drift from New England and Canada. In fact, because the
+glaciers ground southward from the north in possibly five separate advances
+from two contrasting directions (NNE and NW), the astute observer can find
+different striae and erratics from Canada and New England as well as from New
+Jersey and Pennsylvania on our trip. We will see a number of glacial striae and
+erratics at all of our stops today! The prominent lobate, curvilinear fork-like
+spines of Long Island are ridges composed of material bulldozed at the snout of
+a glacier to form the Harbor Hill and Ronkonkoma "moraines" (Figure 5). Recent
+work by Sanders and Merguerian (1991a, b; 1992a; 1994a, b, c) and Sanders,
+Merguerian, and Mills (1993), indicate that they are largely outwash and not
+till as advertised and promoted by previous workers (with top-notch PR
+departments on Madison Avenue). According to these prevailing "experts", the
+Long Island "moraines" mark the southward terminus of a 10,000 year old event
+(“Woodfordian” glacier) when meltback of the glacial front and a sudden
+surge heaped up linear ridges of ground up rocks, clay, and debris (including
+mature sediments from the underlying Cretaceous) to produce moraine lobes. Not
+so fast! We have a different idea based on our moronic studies. After over
+twenty-five years of combined research, Professors Sanders and Merguerian have
+compiled ample evidence in the form of crosscutting glacial striae, roche
+moutonnée structures, superposed tills of contrasting sedimentology and
+boulder content and by the petrologic and field identification of unique
+indicator stones, to help develop a more complicated, protracted, and more
+ancient glacial history for the region (Tables 2, 3). The glaciation of
+Westchester, New York City, and Long Island included a number of advancing
+glaciers (five, we think) which typically terminated their southward advance in
+the present location of Long Island Sound (Figure 6) and deposited outwash fans
+farther south on Long Island by melt waters above a tilted sequence of older,
+eroded sediment strata of the Cretaceous Coastal Plain (Layer VI in Table 2). A
+few advances covered Long Island to create the famous terminal moraine ridges
+but these are from older glaciers that flowed from the NW and were deposited on
+older outwash terraces as shown correctly by Fuller (1914) in Figure 5.
+According to our combined analysis, the earliest glacial advance (V) flowed
+from the NW to SE, deposited reddish brown till and outwash in Staten Island
+and Garvies Point, Long Island and includes the Jameco Gravel. Glacier IV
+advanced from the NNE to SSW and deposited a gray till at Teller’s Point in
+Westchester and the lower till at Target Rock, Long Island. Glacier III was
+from the NW and deposited deltaic sediments (Manhasset Formation of Fuller
+[1914]) into Glacial Lake Long Island and eventually the Ronkonkoma moraine.
+The Harbor Hill moraine was deposited by Glacier II, also from the NW. The
+final (“Woodfordian”) glacier flowed from the NNE and barely touched Long
+Island in our view. (See Figure 6.) Instead, great volumes of water once again
+shed stratified drift southward to cover Long Island. We have no age dating yet
+but base our model on superposition and careful regional studies. Most modern
+workers have adopted a multi-glacier hypothesis in recent years based on this
+new work but the number and timing of glacial advances remains controversial.
+Suffice to say that the “One glacier did it all” school of geology has
+increased their acceptance level 100% - they now admit to two. We say,
+“it’s a good start and a step in the right direction”. Figure 5 - Map of
+Long Island showing the two prominent terminal-moraine ridges and
+profile-sections illustrating Fuller's interpretation of the subsurface
+relationships. Further explanation in text. (Map from A. K. Lobeck, 1939, fig.
+on p. 309 with location lines of Fuller's sections added. Profile-sections from
+M. L. Fuller, 1914, fig. 107, p. 120, rearranged to place easternmost section
+at top, westernmost at bottom.) Figure 6 - Restored profile-section from
+Connecticut to Long Island showing terminus of continental glacier standing in
+what is now Long Island Sound and spreading compositionally mature outwash sand
+and gravel southward to bury the Upper Cretaceous strata of Long Island.
+Extension of Cretaceous beneath glacier is schematic, but is based on the lack
+of feldspar in much of the Long Island outwash. (Drawn by J. E. Sanders in 1985
+using regional relationships shown in W. deLaguna, 1963, fig. 2, p. A10.) LAYER
+VI - CRETACEOUS SEQUENCE OF THE ATLANTIC COASTAL PLAIN The Cretaceous Coastal
+Plain strata of eastern North America are found to underlie broad areas of the
+continental margin (Figure 7). Except for limited exposures at Garvey's Point,
+Sand's Point, and elsewhere on the north shore of Long Island, Cretaceous
+Coastal Plain strata (Layer VI in Table 2) are generally not directly observed
+cropping out on Long Island. Cretaceous strata exist in the subsurface of Long
+Island, Queens, and in Brooklyn as a sequence of southward tilted layers of
+gravel, sand, and clay. (See Figure 6.) They overlie crystalline bedrock and
+Newark strata based on seismic reflection data. North-south-trending stream
+channels are etched onto the Cretaceous strata. These stream channels were
+controlled by and etched into the southward tilted Cretaceous layers during and
+after Pliocene uplift, southward tilting of the Cretaceous strata, and
+subsequent erosion. (See Table 1.) In addition, the channels were undoubtedly
+modified by the erosive action of the earliest glacier (V in Table 2) and
+glacial meltwaters. Thus, after Pliocene oceanward tilting, differential
+uplift, and erosion, the Cretaceous sequence was beveled and unconformably
+overlain by several glacial sequences of Pleistocene age (Figure 7). Figure 7 -
+Diagrammatic map of part of Atlantic Coastal Plain (open stipple) from
+Washington, D. C. (W at lower L) to Cape Cod, Massachusetts showing how the
+inner lowland (close stipple) at the preserved edge of the coastal-plain strata
+has been submerged northeast of New York City (N.Y.). Inset schematic
+profile-section (large vertical exaggeration) extends SE from Philadelphia, PA
+(P) to Atlantic Ocean off Atlantic City, NJ (not shown on map). (A. K. Lobeck,
+1939, p. 456.) The overlying glacial deposits form a permeable layer that
+blankets the Cretaceous strata, two of which (the Magothy and Lloyd
+formations), consist of highly porous, nonlithified sands. As such, they form
+an important subterranean reservoir of fresh water (called an aquifer) that is
+recharged with rain water and partially depleted everytime you turn on a
+faucet, wash your car, water your lawn, water your hamster, or fill up your
+swimming pool. Strata of Cretaceous age do crop out locally, as mentioned, and
+in regions to the south of Long Island from Staten Island to Florida and forms
+the Atlantic Coastal Plain physiographic province. Professor Bennington has
+worked on the stratigraphy and fossil distribution patterns of the Cretaceous
+strata in New Jersey. Autographed copies of his papers and a complete
+“signature” line of sneakers are available at Hip-Hop clubs across the
+country and at Geology Club meetings, Wednesdays, during the common hour in
+Gittleson 135! LAYER V - NEWARK BASIN-FILLING STRATA The tilted and eroded
+remnants of the Newark strata are exposed along the west side of the Hudson
+River, from Stony Point south to Staten Island (Figure 8). As shown there and
+on the diagonal cut-away slice in Figure 4, the Newark strata generally dip
+about 15° to the northwest. The west side of the Hudson River channel is
+marked by an impressive cliff face of highly jointed mafic rock. These
+spectacular cliffs mark the raw, eroded edge of the Palisades intrusive sheet,
+a concordant tabular sill-like igneous body, formerly intruded at depths of 3
+to 4 km into formerly buried Newark strata. Figure 8 - Interpretive geologic
+section across the Hudson River in the vicinity of the George Washington Bridge
+showing westward tilted strata of the Newark Basin and the Palisades intrusive
+sheet and their nonconformable relationship to folded metamorphic rocks of New
+York City. (After Berkey, 1948; digitally enhanced by Geology 18 students.) The
+formal stratigraphic name for the Newark strata is Newark Supergroup. Included
+are various sedimentary formations, of which the basal unit is the Stockton
+Arkose. Above it is the Lockatong Formation, the unit into which the Palisades
+sheet has been intruded. Higher up are other sedimentary units and three
+interbedded sheets of mafic extrusive igneous rock (ancient lava flows), whose
+tilted edges are resistant and underlie ridges known as the Watchungs. The age
+of the sedimentary units beneath the oldest extrusive sheet is Late Triassic.
+The remainder of the formations are of Early Jurassic age. At Stops 2 and 3 you
+will examine some of the red-colored sedimentary rocks of the Newark Basin and
+also see basaltic volcanic rocks of the Orange Mountain Formation. (See Figure
+4.) The Newark sedimentary strata were deposited in a fault-bounded basin
+(Figure 9) to which the sea never gained access. In this basin, the filling
+strata were deposited in various nonmarine environments, including subaerial
+fans, streams, and shallow- and deep lakes. Lake levels varied according to
+changes in climate. After the Newark strata had been deeply buried, they were
+elevated and tilted, probably during a period of mid-Jurassic tectonic
+activities (Merguerian and Sanders, 1994b). Figure 9 - Sketch map and geologic
+profile-section, southeastern New York and adjacent New Jersey. Note lack of
+correspondence in scale between profile-section and map, with resulting
+expansion of the length of AB and shortening of line segment BC. (From Wolff,
+Sichko, and Liebling, 1987.) An important point to be established about the
+Palisades intrusive sheet is its date of intrusion. Its time of intrusion is
+thought to coincide with the time of the extrusion of one or more of the
+Watchung extrusive sheets; the problem is to prove that the Palisades was
+intruded at the same time as one of the Watchung extrusives. According to
+Sichko (1970 ms.), Puffer (1988), and Husch (1990), a likely correlation is
+between the high-Ti magma that solidified to form the Palisades sheet and the
+various lavas that cooled to form the multiple flows of the Orange Mountain
+Formation (First Watchung). The general absence of chilled zones within the
+Palisades sheet implies that all pulses of magmatic activity took place before
+the igneous rock had cooled. Based on their interpretation of the time value of
+sediments deposited under the influence of climate cycles in the associated
+sedimentary strata, Olsen and Fedosh (1988) calculate that approximately 2.5 Ma
+elapsed between the time of extrusion of the Orange Mountain Formation and that
+of the Preakness Formation. This means that if igneous activity within the
+Palisades sheet took place at the same time as that of the extrusion of these
+two ancient lava flows, then more than 2.5 Ma were required for the sheet-like
+Palisades intrusive to cool. If one can prove the synchroneity of intrusion of
+the Palisades intrusive sheet with one or more of the Watchung flows, then a
+further point is settled: depth of intrusion. The depth of intrusion then
+becomes the stratigraphic thickness of Newark strata between the Palisades and
+the First or Second Watchung basalt (roughly 3 to 4 km). Thus, the Palisades
+intrusive sheet may have been dropped to lower (warmer) crustal levels while it
+was attempting to cool. Using the average geothermal gradient of 30°C/km the
+increase in temperature would exceed the boiling point for water! This brings
+the discussion of cooling to a full boil and provides an explanation for long
+duration cooling history for the Palisades intrusive sheet. Studies by
+Merguerian and Sanders (1992a, 1994f, 1995a, b) suggest that the Palisades
+magma was intruded under shallow conditions (~3 to 4 km) and that the magma may
+have originated from the vicinity of Staten Island and flowed northeastward,
+rather than toward the southeast from fractures related to the Ramapo fault as
+most previous workers have argued. Vertical flow features, the great thickness
+of the Palisades in NYC, and the central location of Staten Island support this
+hypothesis. LAYERS I and II - CRYSTALLINE BEDROCK OF THE MANHATTAN PRONG
+Figures 4, 7, 8, and 9 show that the deepest layer in this area consists of
+Paleozoic and Proterozoic metamorphic and metamorphosed igneous rocks
+crystalline basement rocks. These older strata (Layers I and II in Table 2) are
+continuous with rocks exposed along the deeply-eroded spine of the Appalachian
+mountain belt that extends from Georgia northeastward through Maine. Some of
+these crystalline rocks crop out in the Bronx (Stop 1) and in Manhattan and
+form the stable bedrock core atop which the skyscrapers of New York City. They
+are subdivided into two basic sub-layers, an older sequence consisting of ~1.0
+Ga (billion year old) gneisses (Layer I) and a younger sequence of complexly
+deformed and internally sheared schist, gneiss, amphibolite, and marble (Layer
+II). Included in Layer II are Late Proterozoic former rift-facies rocks found
+in the Bronx and Westchester known as the Ned Mountain Formation. Rocks of
+Layers I and II are overlain by Devonian strata of the Catskills (Layer III in
+Table 2). Dr. Wolff has performed important research on the Catskills. Copies
+of his publications can be sought at all Geology Club meetings on Wednesdays
+during the Common Hour in Gittleson 135. Layer I – Crystalline Rocks of the
+Grenville Cycle The rocks of the Grenville cycle (Layer I of Table 2) are the
+oldest recognized strata in southeastern New York. (Note the black stippled
+areas in Figure 4.) They include the Fordham Gneiss in New York City area and
+the Hudson Highlands gneisses (Figure 10). The Highlands gneisses are composed
+of complexly deformed layered feldspathic gneiss, schist, amphibolite,
+calc-silicate rocks, and massive granitoid gneiss. They constitute a complex
+where metamorphosed intrusive rocks form an integral part of the sequence but
+whose internal stratigraphic relationships are poorly understood.
+Grenville-aged (Proterozoic Y) basement rocks include the Fordham Gneiss of
+Westchester County, the Bronx, and the subsurface of western Long Island
+(Queens and Brooklyn Sections, NYC Water Tunnel #3), the Hudson
+Highland-Reading Prong terrane, the Franklin Marble Belt and associated rocks,
+and the New Milford, Housatonic, Berkshire, and Green Mountain Massifs of New
+England. (See Tables 1 and 2.) Taken as a whole, the ancient Grenville-cycle
+sequence unconformably underlies the younger Appalachian-cycle rocks (Layer II)
+described in the next section. Southeast of the Hudson Highlands, the Grenville
+rocks are known as the Fordham Gneiss of the Manhattan Prong. Here they have
+been intricately folded with the Paleozoic-aged rocks of the Appalachian cycle.
+In the Pound Ridge area (PR in Figure 10), the Fordham Gneiss has yielded 1.1
+Ga 207Pb/206Pb zircon ages (Grauert and Hall, 1973) that falls well within the
+range of the Grenville orogeny. Rb/Sr data of Mose (1982) suggest that
+metasedimentary- and metavolcanic protoliths (parent material) of the Fordham
+date back to 1.35 Ga. In Westchester County, subunits in the Fordham are cut by
+the Pound Ridge Gneiss and correlative Yonkers Gneiss. Using Rb-Sr techniques,
+Mose and Hayes (1975) have dated the Pound Ridge Gneiss as Proterozoic Z in age
+(579+21 Ma). This gneiss body shows an intrusive or possibly a nonconformable
+relationship with the Grenvillian basement sequence (Dr. Patrick Brock,
+personal communication). The Yonkers Granitic Gneiss (Y in Figure 10) has
+yielded ages of 563+30 Ma (Long, 1969b) and 530+43 Ma (Mose, 1981). The Pound
+Ridge along with the Yonkers Gneiss, are thought to be the products of latest
+Proterozoic alkali-calcic plutonism (Yonkers) and/or -volcanism (Pound Ridge)
+in response to rifting of the ancient Gondwanan supercontinent. The
+Grenville-cycle units are unconformably overlain either by the Lower Cambrian
+Lowerre quartzite (Hall, 1968a, b, 1976; Brock, 1989) or by a vast rift
+sequence (now metamorphosed) of potash feldspar-rich felsic gneiss,
+calc-silicate rock, volcaniclastic rock, amphibolite gneiss, and minor
+quartzite (Ned Mountain Formation of Brock 1989, 1993). Thus, the
+Grenville-cycle sequence represents the ancient continental crust of
+proto-North America that became a trailing edge, passive continental margin
+early in the Paleozoic Era. Figure 10 - Simplified geologic map of the
+Manhattan Prong showing the distribution of metamorphic rocks from Grenville
+cycle (Layer I; rocks of Proterozoic Y age) and early phases of Appalachian
+cycle (Layer II; rocks of late Proterozoic to Early Paleozoic age). Most faults
+and intrusive rocks have been omitted. (From Mose and Merguerian, 1985, fig. 1,
+p. 21.) Layer II – Metasedimentary and Metavolcanic Rocks of the Appalachian
+Cycle The crystalline bedrock of New York City originated as sedimentary and
+volcanic rocks that originally formed adjacent to the early Paleozoic shelf
+edge of eastern North America (Figure 11). The sedimentary apron was deposited
+across a passive continental margin and produced two sub-parallel belts – a
+shallow water sequence adjacent to the shoreline consisting of sandstone,
+limestone, and shale and a deeper water sequence away from the shelf edge
+consisting of greywacke, shale, and volcanic strata (Figure 12). During the
+Taconic orogeny of medial Ordovician age (See Tables 1 and 2), these disparate
+sequences were juxtaposed, highly folded and metamorphosed in a subduction zone
+that formerly operated adjacent to the east coast of North America. An
+arc-continent collision (Figure 13) was the first in a series of Paleozoic
+plate tectonic events that ultimately produced the Appalachian Mountain chain.
+Figure 11 - Paleogeographic map of North America in Early Paleozoic time
+showing how the east coast on North America was awash in volcanic island arcs
+(Kay, 1951). Figure 12 - Block diagram showing the Lower Paleozoic continental
+shelf edge of embryonic North America immediately before the deposition of
+Layer IIB. Current state outlines are dotted. The depositional areas for Layers
+IIA(W) and IIA(E), and the position of the Taconic arc and foreland basin are
+shown. Thus, in western Connecticut and southeastern New York, Layer I rocks of
+the Grenville cycle are overlain by Cambro-Ordovician formations that are
+products of the early (Taconian) part of the Appalachian cycle (Layer II of
+Table 2). These sedimentary- and igneous rock units have been highly
+metamorphosed, folded, and faulted. They began their geologic lives roughly
+550-450 million years ago as thick accumulations of both shallow- and
+deep-water sediments adjacent to the Early Paleozoic shores of proto-North
+America. (See Figures 10-12.) For ease of discussion, Layer II can be divided
+into two sub-layers, IIA and IIB. The older of these, IIA, represents strata
+deposited along the ancient passive-margin of North America. The passive-margin
+deposits of Layer IIA can be subdivided into two varieties (facies) [IIA(W) and
+IIA(E)] that differ in their original geographic positions with respect to the
+shoreline and shelf edge. A nearshore facies [Layer IIA(W)], deposited in
+shallow water, is collectively designated as the Sauk Sequence. This sequence
+includes former conglomerate, feldspathic sands, and volcanic rocks of the late
+Proterozoic Ned Mountain Formation, basal Cambrian sandy sediment and overlying
+thick Cambro-Ordovician carbonate sediments, which were predominantly dolomitic
+in nearshore areas. The Sauk clastics and -carbonates in New York City are the
+Lowerre Quartzite and Inwood Marble. In western Connecticut and Massachusetts,
+the basal-Sauk sandy unit is the Cheshire Quartzite and the carbonate rocks,
+here containing more limestone than in localities closer to the ancient
+shoreline, are named the Woodville- and Stockbridge Marble. Thus, the Sauk
+strata began life as sandy- and limey sediments in an environment not
+significantly different from the present-day Bahama Banks. In fact, during the
+Appalachian cycle, New York City was situated in the tropical parts of the
+Southern Hemisphere (~20°S latitude); what is now east was then south and what
+is now west, north (Figure 14). Figure 13 - Sequential tectonic cross sections
+for the Taconic orogeny in New England. From the top down the collision of a
+volcanic arc (on right) with the passive continental margin of North America
+(on left) produced the ancestral Appalachians. (From Rowley and Kidd, 1981.)
+Figure 14 - Paleogeographic map showing North America in its Early Paleozoic
+position astride the Earth's Equator. (C. Merguerian and J. E. Sanders, 1996,
+fig. 2, p.118; after C. K. Seyfert and L. A. Sirkin, 1979.) Farther offshore,
+fine-textured terrigenous time-stratigraphic equivalents of the shallow-water
+Sauk strata (shelf sequence) were deposited in deep water on oceanic crust
+[Layer IIA(E)]. This deep-water sequence is also of Cambrian- to Ordovician
+age. In upstate New York, it is known as the Taconic Sequence. Layer IIB
+consists of younger strata designated collectively as the Tippecanoe Sequence.
+The Tippecanoe strata overlie the Sauk Sequence [Layer IIA(W)] above a surface
+of unconformity of regional extent. The change from passive margin to
+convergent margin took place while the Tippecanoe Sequence was accumulating.
+The basal unit of the Tippecanoe Sequence is a limestone (the "Balmville")
+deposited at the end of the passive-margin phase. Overlying this limestone is a
+thick body of dark-colored terrigenous strata, the filling of a foreland basin
+that formed during the earliest part of the convergent-margin regime that
+supplanted the passive-margin regime in mid-Ordovician time. (See Figure 13.)
+Bedrock Geology of New York City Merrill (1890) and Merrill et al. (1902)
+established the name Manhattan Schist for the well-exposed schistose rocks of
+Manhattan Island. A new picture of the geology of New York City has evolved
+from the combined work of many geologists over the past century. Huge capital
+construction projects, both on the surface and in the subsurface, have allowed
+geologists to examine and map large parts of the city where no natural bedrock
+is exposed. Since the early 1980s CM has been able to examine most of the NYC
+Water Tunnel #3 during various construction phases. Based on this work and
+surface mapping in NYC over the same time period, a much more complex
+stratigraphy and structure has been found in comparison to earlier maps and
+reports. Indeed, the bedrock of New York City consists of three ductile fault
+bounded sheets of rock that are intricately folded together as shown on Figures
+15, 16, and 17. Figure 15 – Geologic map of New York City showing the
+generalized structural geology of the region. Blue dot shows the epicenter of
+the 17 January 2001 magnitude 2.4 earthquake that struck NYC. It is located
+along the famous 125th Street “Manhattanville” fault. (Adapted from
+Merguerian and Baskerville, 1987.) The bedrock geology of New York City can
+best be described using the concept of sequence stratigraphy. All of the major
+sequences (Sauk, Taconic, Tippecanoe) are represented there (Figure 16). As
+such, the various metamorphic rocks found in NYC were formerly deposited across
+the Cambro-Ordovician shelf edge of embryonic North America. The former shelf
+(Sauk Sequence) is preserved as the Cambro-Ordovician Inwood Marble (C-Oi) that
+is locally interlayered with autochthonous calcite-marble bearing Middle
+Ordovician Manhattan Schist (Om) of the Tippecanoe Sequence. The Saint Nicholas
+thrust (Taconic frontal thrust) separates lower-plate Tippecanoe (Om) and Sauk
+(C-Oi) rocks from upper-plate gneiss, schist, and amphibolite of the former
+Cambro-Ordovician slope- and rise (Manhattan Formation; C-Om). The structurally
+higher ductile fault mapped as Cameron's Line, juxtaposes muscovite-rich schist
+and gneiss, amphibolite, serpentinite, and coticule of a former deep-water
+realm (Hartland Terrane; C-Oh) with C-Om rocks. All combined together as the
+Manhattan Schist Formation by past workers, the subunits C-Om and C-Oh are here
+considered to be metamorphosed and sheared facies of the Taconic Sequence.
+During Ordovician Taconian arc-continent suturing, the Saint Nicholas thrust
+and Cameron's Line juxtaposed former shelf-, rise-, and deep-water facies in a
+continentward-facing subduction complex (Merguerian 1986, 1996c; Merguerian and
+Sanders 1991b, 1991g, 1993d). Figure 16 - Geologic map of Manhattan Island
+showing a new interpretation of the stratigraphy and structure of Manhattan
+Island. Drawn and mapped by C. Merguerian (unpublished data). Two
+cross-sections (Figure 17) show a simplified view of the geologic structure of
+Manhattan Island. The larger section cuts across northern Manhattan from the
+Hudson River to the Bronx. The W-E section shows the general structure of New
+York City and how the St. Nicholas thrust and Cameron's Line place the middle
+unit of the Manhattan Schist, and the Hartland Formation respectively, above
+the Fordham-Inwood-lower schist unit basement-cover sequence. The major F3
+folds produce digitations of the structural- and lithostratigraphic contacts
+that dip gently south, downward out of the page toward the viewer. The N-S
+section, along Fifth Avenue in Manhattan, illustrates the southward topping of
+lithostratigraphic units and the effects of the late NW-trending upright folds.
+Figure 17 - Geologic cross-sections, keyed to Figures 15 and 16, showing an
+interpretive west-east and north-south structure sections across northern
+Manhattan and the Bronx. Drawn by C. Merguerian. Metamorphic index minerals
+such as garnet, sillimanite, and kyanite are found throughout the metamorphic
+rocks of New York City and the Bronx indicating deep conditions (~30 km or
+more) during their metamorphism. Dr. Ratcliffe has performed important research
+on the mineral kyanite. Copies of his publications are available in all public
+areas on campus or can be sought at all Geology Club meetings on Wednesdays
+during the Common Hour in Gittleson 135. Enough Geological Background for one
+day. Lots of additional information is available by visiting the Geology
+Department webpage, visiting our links, and by downloading our publications. On
+to our Road Log and description of individual field trip localities (stops).
+ROAD LOG AND DESCRIPTIONS OF STOPS Leg 1 - Hofstra Campus west across Long
+Island, and the Bronx, to Pelham Bay Park Heading westward from Hofstra on the
+Long Island Expressway, the extraordinary lack of topographic relief is because
+of the thin layers of glacial deposits (called outwash) that were shed
+southward during post-glacial retreat. These sandy deposits were deposited
+southward from Connecticut, lapping onto the glacial moraines and thus together
+form the surface units of Long Island. Keep an eye out for our first turnoff
+from the LIE. Note how the relief has changed from veritable flatlands to a
+hilly terrain. We are now encountering areas of Queens underlain by the glacial
+ridges of Long Island and cut by tongues of advancing glacial ice and meltwater
+channels. Farther to the west on the LIE near Kissena Boulevard (not passed on
+this trip), Queens College is perched on the intersection point of the two
+terminal moraines described earlier. Heading northward on the Whitestone
+Expressway toward the Throgs Neck Bridge we pass across glacial outwash
+deposits which terminate along the northern border of Queens on the rubbly
+north shore of Long Island. Passing over the Throgs Neck Bridge we pass through
+a time portal separating us from the Pleistocene strata and older, underlying
+Cretaceous deposits of the Coastal Plain onto Proterozoic and Paleozoic
+crystalline rocks exposed in the Bronx. A diagrammatic sketch illustrating the
+structure of these rocks is shown in Figure 18. Note how the Mesozoic
+sedimentary rocks dip toward the south above an erosional surface developed on
+the crystalline rocks. This depositional contact is known as a nonconformity,
+the first of three major ones we will cross today, as it separates rocks of
+vastly different age and lithology. Figure 18 – Diagrammatic north-south
+sketch of the nonconformity beneath the Throgs Neck Bridge and the
+disconformity of Long Island found along our first driving leg. (Drawing by C.
+Merguerian.) Driving northward from the Throgs Neck Bridge on Route 95 we do
+not see much exposed bedrock due to a deep weathering profile. The rocks we are
+driving on through (Layer IIA(E) in Table 2) are a sequence of highly deformed
+and metamorphosed rocks mapped as the Hutchinson River Group (Baskerville,
+1982). Continuous and correlative with rocks of the Hartland Formation (See
+Figures 15 and 16), the Hutchinson River Group is interpreted as a former
+oceanic sequence deposited adjacent to the early Paleozoic shelf edge of
+eastern North America. Together, the crystalline metamorphic rocks of Manhattan
+and the Bronx comprise another physiographic province known as the Manhattan
+Prong. As shown in the cover figure and in Figure 4, the Manhattan Prong
+consists of a northeast-trending, deeply-eroded sequence of metamorphosed
+Proterozoic to Lower Paleozoic rocks, including quartzite, marble, and schist,
+that plunge southward beneath unconformable Cretaceous sedimentary rocks and
+overlying Recent (glacial) sediments in New York City. By contrast to coeval
+(age equivalent) metamorphic rocks cropping out in New York City (Layer IIA(W)
+in Table 2), the Hutchinson River Group contains abundant amphibolite
+(metabasalt) and feldspathic gneiss and does not contain appreciable quartzite
+(metamorphosed sandstone) or marble (metamorphosed limestone) that is so
+typical of the shallow water depositional environment. As such, compared to the
+dominantly miogeosynclinal (shallow water shelf deposits) character of the
+Manhattan Prong west of Cameron's Line, the Hutchinson River Group is decidedly
+eugeosynclinal (deep-water oceanic parentage). Thus, on either side of
+Cameron's Line, an important structural boundary in the New England
+Appalachians, we have disparate sequence of juxtaposed metamorphic rocks of
+roughly equivalent age. In summary, the rocks exposed along I-95 form a
+sequence of highly metamorphosed metasedimentary and metavolcanic rocks of
+Early Paleozoic age [Layer IIA(E)] which trend northeasterly through Orchard
+Beach (STOP 1) and City Island into western Connecticut where they are mapped
+as the Hartland Formation (C-Oh in Figures 10 and 15). Together with their
+northward extensions into Massachusetts, Vermont, and New Hampshire this
+largely metavolcanic rock sequence marks a former oceanic terrane that collided
+with North America during the medial Ordovician Taconic orogeny or mountain
+building event (Figure 13). Imagine the Japanese volcanic islands colliding
+with China and you may picture a modern analog of the Taconic orogeny. A
+diagram illustrating the pre-Taconic paleogeography of the Early Paleozoic
+shelf edge of eastern North America is shown in Figure 11. The depositional
+sites for Layers IIA(W) and IIA(E) are shown. STOP 1 - Hutchinson River Group -
+North and South Twin Islands, near Orchard Beach, Pelham Bay Park, Bronx. (UTM
+Coordinates: 602.4E/4525.0N, Flushing quadrangle.) Rocks of the Hutchinson
+River Group occur in highly glaciated exposures (look for glacial striae, till,
+and erratics) on South and North Twin Islands to the north of Orchard Beach in
+the Bronx. Described by Leveson and Seyfert (1969), and Seyfert and Leveson
+(1968, 1969), these high- to medium- grade metamorphic rocks include gneiss,
+schist, and amphibolite all showing ample evidence for partial melting (fusion)
+into mixed igneous and metamorphic rocks known as migmatites. In addition, many
+pegmatites and veins of quartz occur. A geologic map of the region is
+reproduced in Figure 19. Try to identify some of the major folds on the ground.
+The glacial features of South Twin Island are remarkable and take the form of
+glacial striae oriented N32°W, glacial polish, and roche moutonnée structure.
+In addition to these features, a thin red-brown till, consisting of rounded
+boulders set in a reddish-brown matrix of poorly sorted sand, silt, and clay,
+has been unearthed (dug out) at the northern part of South Twin Island. Beneath
+the till the NW-trending glacial grooves are quite obvious on the glaciated
+bedrock surface (Figure 20). Glacial rounding has produced what Sanders and
+Merguerian (1994b) describe as a roche moutonnée structure on the bedrock at
+the extreme north end of South Twin Island. Here, the bedrock shows evidence of
+being sculpted from both the NW- and NNE- directions. Two important indicator
+stones (large boulders of ultramafic rock) occur on the striated bedrock
+surface. They are derived from an exposure of identical plutonic rocks from the
+Cortlandt Complex found to the NNW in the vicinity of Peekskill, New York. As
+such, they are the products of a glacial advance from the NW (Glacier II or III
+in Table 3). The NW to SE trending striae are also the products of our Glaciers
+II and/or III (Table 3). An older glacier (Glacier IV in Table 3) is
+responsible for NNE initial sculpting of the roche moutonnée structure at the
+north end of South Twin Island. Here, we find no evidence for our youngest
+glacier (I). Seyfert and Leveson (1968) have subdivided the metamorphosed
+bedrock into two major units for the purposes of mapping. The "Felsic Unit"
+includes 95% feldspathic gneiss and 5% sillimanite schist and underlies roughly
+50% of North Twin Island and most of South Twin Island. Contacts between the
+felsic gneiss and schist are gradational over distances of several mm to 10s of
+cm. The gneisses consist of quartz, plagioclase (An33), and biotite with minor
+garnet, muscovite, microcline, sillimanite, magnetite, and apatite. The schist
+unit, although of volumetrically minor importance, consist of plagioclase,
+quartz, biotite, sillimanite, microcline, and garnet with subordinate magnetite
+and muscovite. The calculated chemical composition of the felsic unit suggests
+that their protoliths were interlayered graywackes and shales although CM would
+not discount the possibility that they are largely of volcaniclastic origin.
+The "Mafic Unit" includes amphibolite, diopside-epidote amphibolite, and
+plagioclase-biotite gneiss together with subordinate calcite- and plagioclase-
+rich layers. The amphibolites consist of medium-grained hornblende and
+plagioclase (An37) together with minor biotite, quartz, magnetite, and apatite.
+Garnet occurs locally as porphyroblasts in layers parallel to the
+hornblende-plagioclase foliation. On South Twin Island, the "Mafic Unit" occurs
+as amphibolite, however, the lithologies on North Twin Island include
+diopside-epidote amphibolite, plagioclase-biotite gneiss and calcite- and
+plagioclase- rich layers. Contacts between the felsic and mafic units are
+interpreted as original stratification (bedding) that has been strongly
+modified by folds and faults. The calculated chemical composition of the mafic
+unit suggests that they are similar to olivine basalt and thus, they are
+interpreted as mafic lava flows, sills, and/or tuffs prior to metamorphism with
+the bounding units. Professor Merguerian has mapped much of New York City over
+the past three decades. Copies of his publications (suitable for wrapping fish
+and for soaking up oil spills) are available in boutiques at the Roosevelt
+Field Mall, on the Hofstra Geology webpage, and at all Geology Club meetings,
+Wednesdays, during the common hour in 135 Gittleson Hall. Figure 19 - Geologic
+map of North and South Twin Islands, Pelham Bay Park, the Bronx, New York.
+(From Seyfert and Leveson, 1968.) Figure 20 - Sketch of a glaciated bedrock
+surface exposed by wave action; boulders resting on the linear striae have been
+eroded out of the bluff of till in the background. This sketch (locality not
+given in original source) depicts what can be seen along the shore of Long
+Island Sound at South Twin Island, Pelham Bay Park, New York City. (A. K.
+Lobeck, 1939, upper right-hand sketch on p. 301, from U. S. Geological Survey.)
+Correlative with the Hartland Formation of western Connecticut and southeastern
+New York, the Hutchinson River Group is strongly deformed under high- to
+medium- grade metamorphic conditions. Mapping by CM in 1981-83 showed the
+presence of at least four sets of superposed folds, two early stages of
+isoclinal folds (F1 and F2), followed by tight F3 folds, and gently warping by
+open F4 folds. The F1 and F2 fold phases are superposed and probably
+progressive based on similarities in structural style and orientation compared
+to sequences mapped in New York City and western Connecticut on either side of
+Cameron's Line (Merguerian, 1985, 1986). Significant shearing parallel to the
+axial surfaces of F1 and F2 folds has resulted in folds with sheared out limbs
+and has created beautiful interference patterns. In addition, the generation of
+pegmatitic sweat-outs and bull quartz veins injected parallel to S2 is
+omnipresent which, together, creates local migmatite. The enveloping surface of
+the composite S1+S2 foliation trends roughly N54°W, 60°SW, a bit steeper but
+of identical strike to older fabrics in coeval rocks mapped in Manhattan by
+Merguerian (1983b). The F3 folds deform the penetrative S1+S2 foliation and as
+a result are quite obvious in outcrop. They possess axial surfaces trending
+N30°E, 75°SE to vertical. The plunge of F3 axes is dominantly south to
+southeastward at roughly 45°- 60° but variable due to differences in the
+original orientation of S1 and S2 foliations and younger, F4 warps. The F3 axes
+are obvious as mineral streaking on the S2 foliation and as the long axis of
+boudins. On North Twin Island, extensive boudinage of the mafic rocks and
+diopsidic calc-marble into sheared boudins occurs due to ductility contrasts
+with the surrounding felsic units. The F4 folds are larger than outcrop scale
+but show up as broad open warps of preexisting structures and a slip cleavage
+oriented roughly N85°E, 80°NW. Again, the similarities in structural sequence
+and orientation between these rocks and those mapped by CM in New York City are
+striking with all four-fold phases recognized in both regions. Because the
+structural geology of both regions are identical, they must share a common
+plate tectonic history. The two regions also show similar brittle fault
+histories. Many excellent examples of brittle faults of contrasting type and
+offset sense can be found in the bedrock exposures half way up the rock terrace
+on South Twin Island. See if you can find them. Give up? One of the rock
+exposures displays a fault oriented N42°E, 76°NW that exhibits 0.4 m of
+left-lateral strike-slip displacement as measured across an offset quartz vein
+(Figure 21). The offset vein outlines an older fault that can be traced toward
+the east where important geological relationships can be observed. Here the
+rock terrace displays two faults of contrasting type and orientation, indeed a
+textbook example of relative age determination based on crosscutting
+relationships. Figure 22 shows an eastward view of two faults. Note how the
+N70°W-trending strike slip-fault offsets a quartz vein in the background. The
+vein was injected into a N30°E shear zone (ductile fault) developed parallel
+to foliation in the bounding Hartland gneiss. Thus, both brittle and ductile
+faults can be observed in a single exposure. Elsewhere to the south, another
+NW-trending fault is exposed. This fault trends N66°W and dips 82°SW and
+shows roughly 0.5 m of composite offset of an isolated quartz vein. The area
+around the fault is highly fractured because of a family of joints oriented
+N67°W, 77°SW. Experienced field geologists look for evidence of decreased
+joint spacing to localize faults in the field and this location illustrates all
+of the traits of a fault. Although similar in orientation to the NW-trending
+fault described above, this fault exhibits right-lateral strike-slip offset.
+This isolated NW-trending fault may be part of a family of NW-trending faults
+that are considered active in that they exhibit post-glacial offset and
+localize new earthquakes. They are similar in orientation and offset sense to
+the fault along which the 17 January 2001 NYC earthquake was localized. (See
+Figure 15.) Based on traditional bedrock mapping on the surface and detailed
+mapping in the NYC Water Tunnels, Merguerian (2002) has demonstrated that the
+NW-trending faults of NYC are the youngest in the region. Thus, as described
+earlier, the rocks of the Hutchinson River Group are interpreted as the
+remnants of an ocean basin adjacent to the Early Paleozoic shelf edge of North
+America and fringed by a volcanic arc. While walking on the outcrop surface
+with your lab instructors see if you can identify the various rock types,
+folds, faults, joints, deformational structures, and glacial features discussed
+above. Figure 21 – A N42°E-trending brittle fault that dips 76°NW with 0.4
+m composite left-lateral offset. This younger fault cuts the veined N70°W
+fault of Figure 22. Figure 22 – Eastward view of N70°W, 62°NE left-lateral
+fault (lined by large milky quartz vein). This fault cuts an older NE-trending
+fault and parallel foliation (N30°E, 80° SE) in the bounding Hartland gneiss.
+Leg 2 - From Orchard Beach across the Bronx and Manhattan into New Jersey
+Driving westward through the Bronx on the Cross Bronx Expressway (I-95) note
+the outcrops (and abandoned appliances and cars) on either side of the roadway.
+The first exposures you see are metamorphic rocks assigned to the Hartland
+Formation/Hutchinson River Group. Near the western edge of the New York
+Botanical Garden and the Bronx Zoo in the Bronx the fault contact of the
+Hutchinson-Hartland Terrane with the Manhattan Prong is exposed. Mapped from
+New York City into western Connecticut, this zone of highly sheared metamorphic
+rocks, known as mylonites, are developed along Cameron's Line. This shear zone
+(suture) separates rocks of oceanic parentage to the east [Layer IIA(E)] from
+rocks of continental affinities to the west [Layers I, IIA(W), and IIB] and
+marks an important geologic boundary for the Appalachian mountain belt through
+southeastern New York into New England. The St. Nicholas thrust separates
+Taconic rocks of the Manhattan Schist from the Walloomsac (Tippecanoe) Schist
+in the New York Botanical Garden, Boro Hall Park, and Crotona Park and across
+our trip route. This regionally important shear zone cuts across the Cross
+Bronx Expressway just before the Third Avenue exit. Westward past Third Avenue
+occur exposures of the Manhattan Schist and Inwood Marble. Recently, Drs.
+Patrick and Pamela Brock have found exposures of the late Proterozoic Ned
+Mountain Formation in numerous places in the Bronx, indicating that imbrication
+of rock types in the highly sheared core zone of mountain ranges is the rule,
+not the exception. Look on the northern side of the Cross Bronx Expressway and
+see if you can spot an anticline (upfold) of amphibolite in the Proterozoic
+Fordham Gneiss that crops out at an entrance ramp before Jerome Avenue. Beyond
+Jerome Avenue, the substrate above which the Manhattan-Inwood sediments were
+deposited crops out. Originally part of the ancient North American craton these
+highly folded and metamorphosed rocks are the Proterozoic Fordham Gneiss that,
+in excellent exposures to the north and south of the expressway, show the
+typical banded and highly folded appearance of gneiss. Note the abundance of
+folds and faults in the Fordham in large cliff-like cuts, just before we cross
+the East River near Highbridge. Passing beneath the apartment complex built
+atop the expressway we skirt across the northern tip of Manhattan Island, also
+composed of the Manhattan-Inwood-Fordham metamorphic rocks. (See Figure 15.) As
+we cross the Hudson River over the George Washington Bridge we catapult forward
+in time passing from the Proterozoic and Paleozoic rocks of Manhattan and the
+Bronx into gently west-dipping red-colored sedimentary rocks of the Newark
+Basin. Figure 8 is a diagrammatic sketch showing the structure of the bedrock
+beneath the George Washington Bridge (see Figure on cover also!). The prominent
+cliffs on the west bank of the Hudson River, the Palisades, are formed by the
+tilted, resistant edge of the igneous rocks of the Palisades sheet which forms
+a sill-like intrusive. As you should remember, a sill is a concordant tabular
+pluton, a sheet-like body of igneous rock that has been intruded parallel to
+the layers of its surrounding rocks. A diagrammatic cross section of the
+Palisades sheet is reproduced as Figure 23. The composition of this mafic rock
+is quite similar to the mafic rocks of the oceanic crust. Mafic rocks are named
+by the coarseness of their crystals: gabbro is the coarse variety; dolerite,
+the intermediate variety; and basalt, the fine variety. Figure 23 - Schematic
+cross-section of the Palisades intrusive sheet, New Jersey. (Drawn by M.
+Sichko.) Because of the prevailing northwest dip in the central part of Newark
+Basin, as we drive northwestward during the remainder of today's trip, we will
+encounter successively younger strata among the Newark basin-filling strata.
+Geologists refer to traverses across the strike of strata starting with older
+strata and encountering successively younger strata as "traversing up section"
+(the "section" referring to the succession of strata, and the "up" to the
+progression from older strata to younger). By contrast, they refer to the
+reverse, that is, a traverse progressing from younger strata to older, as
+"traversing down section"). Try to locate the top of the Palisades sheet and
+look for outcrops of Layer V (red shale, sandstone, and conglomerate) on both
+sides of Route 80 in New Jersey as we drive westward towards Stops 2 and 3.
+After crossing the outcrop belt of the Palisades intrusive sheet, and across
+red-colored sedimentary rocks of Layer V, we will eventually view high-standing
+ridges of the First, Second, and Third Watchung Mountains. (See Figures 4 and
+8.) Thus, from the upper contact of the Palisades sheet, we will drive past
+west-dipping sedimentary rocks of the Newark Supergroup on our way to stops to
+examine the first of three sheets of extrusive mafic igneous rock constituting
+the Orange Mountain Formation ("First Watchung basalt" of older usage), the
+Preakness Formation (former "Second Watchung basalt"), and Hook Mountain
+Formation (formerly "Third Watchung basalt"; each "basalt" named after one of
+the Watchung mountains that were numbered from east to west). These curvilinear
+mountain ridges are truncated on the northwest by the Ramapo fault, a normal
+(gravity) fault that juxtaposes the Hudson Highlands block (footwall) on the NW
+and the Newark Basin (hanging wall) on the SE. The Newark Supergroup is a thick
+sequence of Late Triassic to Early Jurassic (Mesozoic) sedimentary strata and
+interbedded sheets of mafic volcanic rocks whose basal part was intruded by a
+thick sheet of mafic magma that cooled to form the Palisades Intrusive sheet.
+The Newark Supergroup (Layer V in Table 2) rests with profound angular
+unconformity atop folded and faulted units of Layers I and II, the pre-Newark
+complex of Paleozoic and older metamorphic rocks that underlies the Manhattan
+Prong of the New England Uplands. (See Figure 4.) Rocks of Layer I crop out
+immediately west of the Ramapo fault zone. Here, they underlie the Ramapo
+Mountains, a tract of hilly, highly glaciated crystalline rocks. These rocks
+lie along strike and are correlative with Proterozoic rocks of the Hudson
+Highlands. The tilted and eroded edges of the Newark strata were overlapped and
+covered by the strata of Layer VI, the coastal-plain strata. Recent work by
+many geologists has defined the stratigraphy of the Watchung basalts and
+intercalated sedimentary strata (Figure 24). The outcrop pattern of these
+various formations in New Jersey are shown in Figure 25 based on a proposed
+flood-diversion tunnel as discussed below. Figure 24 - Columnar section of
+Newark Supergroup from upper part of Passaic Formation to Boonton Formation.
+Block diagram showing the downflow bending of pipe amygdules found at the base
+of the Watching basalts flows. (From Manspeizer, 1980.) Figure 25 - Geologic
+map in the vicinity of proposed flood-diversion tunnel. Dots mark sites of core
+borings made in 1985 and 1986. (From Fedosh and Smoot, 1988.) Our second stop
+today will be in Paterson, New Jersey where extrusive basalts (Orange Mountain
+formation) of the First Watchung Mountain are exposed in a spectacular setting
+known as Paterson Falls. To get there from Stop 1, after crossing the George
+Washington Bridge, take Route 80 West and take the Express Lanes. Continue west
+on Route 80 to Exit 56 (Squirrelwood Road - West Paterson and Paterson, New
+Jersey) and bear R at fork at end of exit ramp. Make first L onto Glover Avenue
+and take Glover down to McBride Avenue along the east side of the Passaic
+River. Turn R on McBride and travel for 0.7 mi. past a spectacular exposure of
+basaltic pillow lavas on east side of McBride Ave. Continue north on McBride
+Ave for 0.3 mi. At traffic light, turn R and take the first L past the Paterson
+Visitor’s Center. After 0.2 mi. turn L and park. STOP 2 - The Great Falls of
+Paterson; Orange Mountain and Passaic formations. (UTM Coordinates:
+568.9E/4529.5N for hillside exposures E and N of stadium, 569.05E/4529.75 N for
+basal contact, 569.15E/4529.85N for cliff face near dog pound, and glacial
+erratic at 568.95E - 4529.65 N. Paterson quadrangle.) Here, at the Great Falls
+of Paterson, New Jersey, (former home of Lou Costello), the Passaic River cuts
+through extrusive sheets of the Orange Mountain (First Watchung) lava flow.
+Professor Sichko has performed petrologic research comparing the Palisades
+intrusive sheet to parts of the First Watchung lava (Sichko, 1970 ms., 1975).
+Autographed copies of his papers are available at newsstands across the country
+and at Geology Club meetings, Wednesdays, during the common hour in Gittleson
+135! As discussed earlier, recent studies suggest that the Palisades magma was
+intruded over a protracted time period spanning the interval from the first to
+the second Watchung lava outpourings. The waterfall here drops about 75 feet
+(from the 120-foot contour at the lip to about 45 feet 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). The view downstream from the
+footbridge (made famous in the TV series “The Sopranos”) shows that igneous
+rock extends all the way to the water's edge on the lower level (altitude about
+45 feet). Keep this fact in mind as we move northward past the stadium. Notice,
+also, that you are all wet from standing in the mist too long. Luckily, the
+quantity of water flowing over Great Falls has been lower than normal lately
+because of the withdrawls allowed to various upriver communities (they drink
+this stuff -- after treatment, of course). Walk northward toward the soccer
+stadium and proceed down the path toward the river. Stop at the first exposure
+(on S side of a small knoll beneath the d of the label Stadium; enclosed by the
+170-foot contour line). Find the contact at the base of the Orange Mountain
+Formation (or of one of the extrusive sheets within this formation if not the
+base) and the underlying pebbly sandstone (top of Passaic Formation or a
+sedimentary member within the Orange Mountain Formation). Notice the
+relationship between the landscape and the contact: a small bench at the top of
+the sandstone; trees growing where they can send roots into the cliff. The
+altitude of the contact here is about 100 feet, which is about 50 feet higher
+than the base of the basalt downstream from the falls. About 10 years ago,
+during a class field trip, Dr. Sanders noticed this relationship and
+interpreted the offset as being the effect of a fault with displacement of at
+least 50 feet. CM and JES think that the northward- and upward shift of the
+basal contact of the extrusive rock is evidence for two other small faults.
+Notice the sequence of columnar joints in the extrusive rock and the chilled
+margin at the base. The top of the flow unit is not exposed here, but if it
+were, what features might be present to enable you to distinguish the sheet as
+an extrusive as contrasted with an intrusive? Note the features of the Passaic
+Formation (if that is what these strata are, and not sedimentary members of the
+Orange Mountain Formation). In your analysis, include bedding characteristics,
+sizes of channels, composition of pebbles, and coarseness of particles. Note
+that the average trend of the channels is into a direction S85°W and that the
+inferred paleoflow of the water in them is from the east! [This is quite in
+contrast to the accepted view that the Newark Basin filled in with sediment
+derived from the uplifted highlands (Ramapo Mountains) to the west.] Note the
+numbers marked by various methods on the cliff face near the dog pound, an
+attempt by an unknown geologist(s) to break out individual units. Three
+channels are especially obvious. The lowest one occurs below unit 5, a second
+between units 9 and 10, and the third between units 14 and 15. The channels are
+indicated by sharp contrasts in grain size and by the presence of pebbles in
+their basal parts. The pebbles are largely (&gt;50%) carbonate with lesser
+amounts of quartz and recycled red sandstone. JES and CM suggest that the
+dominantly structureless, uniform, locally laminated sands and interspersed
+rudites here are the result of flash floods which produced debris flows on the
+outer fringes of a subaerial fan as contrasted with the upward-fining
+cross-stratified point-bar successions formed by the migration of meandering
+streams; in this regard, the absence of shales is especially significant. Thus,
+we suggest that the sediment blankets are true time-stratigraphic horizons
+similar to their interlayered volcanic conterparts. On the walk back up the
+trail, notice the large, polished boulder of hornblende-bearing Proterozoic
+gneiss. It is an erratic weathered out of Pleistocene till and must have come
+from the west, northwest, or north. Leg 3 - Paterson Falls to Garrett Mountain
+Preserve, New Jersey On leaving Great Falls parking area, turn R and follow
+over the bridge and turn L onto McBride Avenue heading south. At Glover Avenue
+traffic light turn L. After a few blocks, turn R onto Squirrelwood Road and
+continue straight over the overpass of Route 80. Before Mobil station, turn L
+into the Mid-Atlantic Plaza and bear L through parking area past Mid-Atlantic
+Bank building. Continue ahead and turn L at stop sign onto New Street. After
+0.3 mi. note the famous New Street quarry on R and continue 0.1 mi. to Dixon
+Avenue. Turn R onto Dixon and follow uphill for 0.25 mi., then turn R onto
+Garrett Street. Follow Garrett Street around to L and then bear R past blocks
+of pillowed basalt on Mountain Avenue (Condos on right of Holocene age!). After
+0.35 mi. turn L into Garrett Mountain Reservation and turn R into park. Follow
+road (south) past Barbour Pond. At 0.8 mi. from park entrance turn L at stop
+sign. Follow road for 0.6 mi. past stop sign and park in small lot to left of
+road across from the tower. STOP 3 - Upper, glaciated contact of the Orange
+Mountain Formation ("First Watchung basalt") at Garrett Mountain Reservation.
+(UTM Coordinates: Location of old house [altitude = 500 feet] 569.50E/4577.75
+N, Paterson quadrangle.) From parking lot, follow trail uphill to the building,
+and then take the trail along the crest of the ridge. Part way up the hill is a
+large erratic of hornblende-bearing granitic rock from the Proterozoic of the
+Hudson Highlands. Does the hornblende mean that it came from west of Hudson?
+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 are 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
+N10°E-S10°W (produced by Glacier III or IV in Table 3), about parallel to the
+trend of Garrett Mountain, and the mini-roche moutonnée. The recent floods
+have been another catastrophe to those living near the junction of the Pompton
+and Passaic rivers but probably have strengthened the arguments for the U. S.
+Army Corps of Engineers and sundry politicians who have been advocating the
+construction of the flood-diversion tunnel, the proposed route of which is
+shown by the dots marking core sites in Figure 25. During 1990-91, other cores
+have been collected at points selected to extend the stratigraphic coverage
+from the strata penetrated by the line of cores along the proposed route of the
+flood-diversion tunnel so as to yield cores through the full thickness of the
+strata filling the Newark basin. These are housed at Lamont-Doherty Geological
+Observatory of Columbia University and are being studied by Paul Olsen and
+associates. The Garrett Mountain block lies east of a fault that is downthrown
+on the east. JES suspects that another fault, possibly the one extending
+northward from the label Orange Mountain Basalt in the lower center of Figure
+17, may be upthrown on the east, thus bringing up the Passaic Formation against
+higher-than-normal parts of the Orange Mountain Formation. JES suspects that
+this up-on-the-east fault extends NE-SW along the eastern side of the First
+Watchung Mountain. If so, then this fault defines a horst block with the Garret
+Mountain block. Under this fault hypothesis, the only places where the full
+thickness of the Orange Mountain Formation would be exposed are located at the
+northeast- and southwest ends of the Watchung ridges, where the curvature of
+the strata on the limbs of the transverse Watchung syncline causes the outcrop
+belts to curve around to the northwest away from this possible fault. Leg 4 -
+Garrett Mountain Preserve back to the Hofstra Campus. Continue north on Garrett
+Mountain loop access road to exit. Turn L onto main road and at 0.8 mi. turn L
+onto Weasel Drift Road. Follow up over crest of Garrett Mountain and then down
+to Valley Road (aka Mountain Park Road). At Getty station, turn L onto Valley
+Road (northbound) and bear L to Route 19, taking 19 to Route 80 (eastbound) to
+Hofstra University. Here's a chance to see it all again in reverse. We will try
+to stop for bathroom facilities along the way. Feel free to ask questions of
+your trip leaders and enjoy the scenery on the way home. We sincerely hope
+you've enjoyed your fieldtrip to southeastern New York and eastern New Jersey
+and hope you have a new appreciation of the geology of the region. See you in
+class! TABLES Table 01 - GEOLOGIC TIME CHART (with selected major geologic
+events from southeastern New York and vicinity) ERA Periods Years Selected
+Major Events (Epochs) (Ma) CENOZOIC (Holocene) 0.1 Rising sea forms Hudson
+Estuary, Long Island Sound, and other bays. Barrier islands form and migrate.
+(Pleistocene) 1.6 Melting of last glaciers forms large lakes. Drainage from
+Great Lakes overflows into Hudson Valley. Dam at The Narrows suddenly breached
+and flood waters erode Hudson shelf valley. Repeated continental glaciation
+with five? glaciers flowing from NW and NE form moraine ridges on Long Island.
+(Pliocene) 6.2 Regional uplift, tilting and erosion of coastal-plain strata;
+sea level drops. Depression eroded that later becomes Long Island Sound.
+(Miocene) 26.2 Fans spread E and SE from Appalachians and push back sea. Last
+widespread marine unit in coastal-plain strata. MESOZOIC 66.5 (Cretaceous) 96
+Passive eastern margin of North American plate subsides and sediments (the
+coastal-plain strata) accumulate. 131 (Passive-margin sequence II). (Jurassic)
+Baltimore Canyon Trough forms and fills with 8,000 feet of pre- Cretaceous
+sediments. Atlantic Ocean starts to open. Newark basins deformed, arched,
+eroded. 190 Continued filling of subsiding Newark basins and mafic igneous
+(Triassic) activity both extrusive and intrusive. Newark basins form and fill
+with non-marine sediments. PALEOZOIC 245 (Permian) Pre-Newark erosion surface
+formed. 260 Appalachian orogeny. (Terminal stage.) Folding, overthrusting, and
+metamorphism of Rhode Island coal basins; granites intruded. (Carboniferous)
+Faulting, folding, and metamorphism in New York City area. Southeastern New
+York undergoes continued uplift and erosion. (Devonian) 365 Acadian orogeny.
+Deep burial of sedimentary strata. Faulting, folding, and metamorphism in New
+York City area. Peekskill Granite and Acadian granites intruded. (Silurian) 440
+Taconic orogeny. Intense deformation and metamorphism. 450 Cortlandt Complex
+and related rocks intrude Taconian suture zone. (Cameron's Line). Arc-continent
+collision. Great overthrusting from ocean toward continent. Taconic
+(Ordovician) deep-water strata thrust above shallow-water strata. Ultramafic
+rocks (oceanic lithosphere) sliced off and transported above deposits of
+continental shelf. Shallow-water clastics and carbonates accumulate in west of
+basin (= Sauk Sequence; protoliths of the Lowerre Quartzite, Inwood Marble,
+part of Manhattan Schist Fm.). Deep-water terrigenous silts form to east. (=
+Taconic Sequence; (Cambrian) protoliths of Hartland Formation, parts of
+Manhattan Schist Fm.). (Passive-margin sequence I). PROTEROZOIC 570 Period of
+uplift and erosion followed by subsidence of margin. (Z) 600 Rifting with rift
+sediments, volcanism, and intrusive activity. (Ned Mountain, Pound Ridge, and
+Yonkers gneiss protoliths). (Y) 1100 Grenville orogeny. Sediments and volcanics
+deposited, compressive deformation, intrusive activity, and granulite facies
+metamorphism. (Fordham Gneiss, Hudson Highlands and related rocks). ARCHEOZOIC
+2600 No record in New York. 4600 Solar system (including Earth) forms. Table 02
+Generalized Descriptions of Major Geologic "Layers", SE New York State and
+Vicinity This geologic table is a tangible result of the On-The-Rocks Field
+Trip Program conducted by Drs. John E. Sanders and Charles Merguerian between
+1988 and 1998. In Stenoan and Huttonian delight, we here present the
+seven-layer cake model that has proved so effective in simplifying the complex
+geology of the region. LAYER VII - QUATERNARY SEDIMENTS A blanket of irregular
+thickness [up to 50 m or more] overlying and more or less covering all older
+bedrock units. Includes four or five tills of several ages each of which was
+deposited by a continental glacier that flowed across the region from one of
+two contrasting directions: (1) from N10°E to S10°W (direction from Labrador
+center and down the Hudson Valley), or (2) from N20°W to S20°E (direction
+from Keewatin center in Hudson's Bay region of Canada and across the Hudson
+Valley). The inferred relationship of the five tills is as follows from
+youngest [I] to oldest [V]. [I] - Yellow-brown to gray till from NNE to SSW,
+[II] - red-brown till from NW to SE, [III] - red-brown till from NW to SE, and
+[IV] - yellow-brown to gray till from NNE to SSW, and [V] - red-brown till from
+NW to SE containing decayed stones (Sanders and Merguerian, 1991a,b, 1992,
+1994a, b; Sanders, Merguerian, and Mills, 1993; Sanders and others, 1997;
+Merguerian and Sanders, 1996). Quaternary sediments consist chiefly of till and
+outwash. On Long Island, outwash (sand and gravel) and glacial lake sediment
+predominates and till is minor and local. By contrast, on Staten Island, tills
+and interstratified lake sediments predominate and sandy outwash appears only
+locally, near Great Kills beach. (See Table 3.) [Pliocene episode of extensive
+and rapid epeirogenic uplift of New England and deep erosion of major river
+valleys, including the excavation of the prominent inner lowland alongside the
+coastal-plain cuesta; a part of the modern landscape in New Jersey, but
+submerged in part to form Long Island Sound]. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER VI - COASTAL-PLAIN STRATA (L.
+Cretaceous to U. Miocene; products of Passive Continental Margin II -
+Atlantic). Marine- and nonmarine sands and clays, present beneath the
+Quaternary sediments on Long Island (but exposed locally in NW Long Island and
+on SW Staten Island) and forming a wide outcrop belt in NE New Jersey. These
+strata underlie the submerged continental terrace. The basal unit (L.
+Cretaceous from Maryland southward, but U. Cretaceous in vicinity of New York
+City) overlaps deformed- and eroded Newark strata and older formations. Also
+includes thick (2000 m) L. Cretaceous sands and shales filling the offshore
+Baltimore Canyon Trough. At the top are Miocene marine- and coastal units that
+are coarser than lower strata and in many localities SW of New Jersey, overstep
+farther inland than older coastal-plain strata. Capping unit is a thin (&lt;50
+m) sheet of yellow gravel (U. Miocene or L. Pliocene?) that was prograded as
+SE-directed fans from the Appalachians pushed back the sea. Eroded Newark
+debris is present in L. Cretaceous sands, but in U. Cretaceous through Miocene
+units, Newark-age redbed debris is conspicuously absent. This relationship is
+considered to be proof that the coastal-plain formations previously buried the
+Newark basins so that no Newark-age debris was available until after the
+Pliocene period of great regional uplift and erosion. The presence of resistant
+heavy minerals derived from the Proterozoic highlands part of the Appalachians
+within all coastal-plain sands indicates that the coastal-plain strata did not
+cover the central highlands of the Appalachians. [Mid-Jurassic to Late Jurassic
+episode of regional arching of Newark basin-filling strata and end of sediment
+accumulation in Newark basin; multiple episodes of deformation including
+oroclinal "bending" of entire Appalachian chain in NE Pennsylvania (Carey,
+1955), and one or more episodes of intrusion of mafic igneous rocks, of
+folding, of normal faulting, and of strike-slip faulting (Merguerian and
+Sanders, 1994b). Great uplift and erosion, ending with formation of Fall-Zone
+planation surface]. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER V - NEWARK BASIN-FILLING STRATA (Upper
+Triassic and Lower Jurassic) Newark-age strata unconformably overlie folded-
+and metamorphosed Paleozoic strata of Layer II and some of the Proterozoic
+formations of Layer I; are in fault contact with other Proterozoic formations
+of the Highlands complex. Cobbles and boulders in basin-marginal rudites near
+Ramapo Fault include mostly rocks from Layers III, IIB, and IIA(W), which
+formerly blanketed the Proterozoic now at the surface on the much-elevated
+Ramapo Mountains block. The thick (possibly 8 or 9 km) strata filling the
+Newark basin are nonmarine. In addition to the basin-marginal rudites, the
+sediments include fluvial- and varied deposits of large lakes whose levels
+shifted cyclically in response to climate cycles evidently related to
+astronomic forcing. A notable lake deposit includes the Lockatong Formation,
+with its analcime-rich black argillites, which attains a maximum thickness of
+about 450 m in the Delaware River valley area. Interbedded with the Jurassic
+part of the Newark strata are three extrusive complexes, each 100 to 300 m
+thick, whose resistant tilted edges now underlie the curvilinear ridges of the
+Watchung Mountains in north-central New Jersey. Boulders of vesicular basalt in
+basin-marginal rudites prove that locally, the lava flows extended
+northwestward across one or more of the basin-marginal faults and onto a block
+that was later elevated and eroded. The thick (ca. 300 m) Palisades intrusive
+sheet is concordant in its central parts, where it intrudes the Lockatong at a
+level about 400 m above the base of the Newark strata. To the NE and SW,
+however, the sheet is discordant and cuts higher strata (Merguerian and
+Sanders, 1995a). Contact relationships and the discovery of clastic dikes at
+the base of the Palisades in Fort Lee, New Jersey, suggest that the mafic magma
+responsible for the Palisades was originally intruded at relatively shallow
+depths (roughly 3 to 4 km) according to Merguerian and Sanders (1995b).
+Xenoliths and screens of both Stockton Arkose and Lockatong Argillite are
+present near the base of the sill. Locally, marginal zones of some xenoliths
+were melted to form granitic rocks (examples: the trondhjemite formed from the
+Lockatong Argillite at the Graniteville quarry, Staten Island, described by
+Benimoff and Sclar, 1984; and a "re-composed" augite granite associated with
+pieces of Stockton Arkose at Weehawken and Jersey City, described by J. V.
+Lewis, 1908, p. 135-137). [Appalachian terminal orogeny; large-scale
+overthrusts of strata over strata (as in the bedding thrusts of the "Little
+Mountains east of the Catskills" and in the strata underlying the NW side of
+the Appalachian Great Valley), of basement over strata (in the outliers NW of
+the Hudson Highlands, and possibly also in many parts of the Highlands
+themselves), and presumably also of basement over basement (localities not yet
+identified). High-grade metamorphism of Coal Measures and intrusion of granites
+in Rhode Island dated at 270 Ma. Extensive uplift and erosion, ending with the
+formation of the pre-Newark peneplain]. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER IV - COAL MEASURES AND RELATED STRATA
+(Carboniferous) Mostly nonmarine coarse strata, about 6 km thick, including
+thick coals altered to anthracite grade, now preserved only in tight synclines
+in the Anthracite district, near Scranton, NE Pennsylvania; inferred to have
+formerly extended NE far enough to have buried the Catskills and vicinity in
+eastern New York State (Friedman and Sanders, 1982, 1983). [Acadian orogeny;
+great thermal activity and folding, including metamorphism on a regional scale,
+ductile deformation, and intrusion of granites; dated at ~360 Ma]. LAYER III -
+MOSTLY MARINE STRATA OF APPALACHIAN BASIN AND CATSKILLS (Carbonates and
+terrigenous strata of Devonian and Silurian age) (Western Facies) (Eastern
+Facies) Catskill Plateau, Delaware SE of Hudson-Great Valley Valley monocline,
+and "Little lowland in Schunnemunk- Mountains" NW of Hudson-Great Bellvale
+graben. Valley lowland. Kaaterskill redbeds and cgls. Schunnemunk Cgl. Ashokan
+Flags (large cross strata) Bellvale Fm., upper unit Mount Marion Fm. (graded
+layers, Bellvale Fm., lower unit marine) (graded layers, marine) Bakoven Black
+Shale Cornwall Black Shale Onondaga Limestone Schoharie buff siltstone Pine
+Hill Formation Esopus Formation Esopus Formation Glenerie Chert Connelly
+Conglomerate Connelly Conglomerate Central Valley Sandstone Carbonates of
+Helderberg Group Carbonates of Helderberg Group Manlius Limestone Rondout
+Formation Rondout Formation Decker Formation Binnewater Sandstone Poxono Island
+Formation High Falls Shale Longwood Red Shale Shawangunk Formation Green Pond
+Conglomerate [Taconic orogeny; 480 Ma deep-seated folding, dynamothermal
+metamorphism and mafic- to ultramafic (alkalic) igneous intrusive activity
+(dated in the range of 470 to 430 Ma) across suture zone (Cameron's Line-St.
+Nicholas thrust zones). Underthrusting of shallow-water western carbonates of
+Sauk Sequence below supracrustal deep-water eastern Taconic strata and
+imbrication of former Sauk-Tippecanoe margin. Long-distance transport of strata
+over strata has been demonstrated; less certain locally is proof of basement
+thrust over strata and of basement shifted over basement. In Newfoundland, a
+full ophiolite sequence, 10 km thick, has been thrust over shelf-type
+sedimentary strata]. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER II - CAMBRO-ORDOVICIAN
+CONTINENTAL-MARGIN COVER (Products of Passive Continental Margin I - Iapetus).
+Subdivided into two sub layers, IIB and IIA. Layer IIA is further subdivided
+into western- and eastern facies. LAYER IIB - TIPPECANOE SEQUENCE - Middle
+Ordovician flysch with basal limestone (Balmville, Jacksonburg limestones). Not
+metamorphosed / Metamorphosed Martinsburg Fm. / Manhattan Schist (Om - lower
+unit). Normanskill Fm. / Annsville Phyllite Subaerial exposure; karst features
+form on Sauk (Layer IIA[W]) platform. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER IIA[W] - SAUK SEQUENCE LAYER IIA[E] -
+TACONIC SEQUENCE Western shallow-water Eastern deep-water zone platform (L.
+Cambrian- (L. Cambrian-M. Ordovician) M. Ordovician) Copake Limestone
+Stockbridge Rochdale Limestone or Inwood Marbles Halcyon Lake Fm. Briarcliff
+Dolostone (C-Oh) Hartland Fm. Pine Plains Fm. (C-Om) Manhattan Fm. Stissing
+Dolostone (in part). Poughquag Quartzite Lowerre Quartzite [Base not known]
+[Pre-Iapetus Rifting Event; extensional tectonics, volcanism, rift-facies
+sedimentation, and plutonic igneous activity precedes development of Iapetus
+[Layer II = passive continental margin I] ocean basin. Extensional interval
+yields protoliths of Pound Ridge Gneiss, Yonkers granitoid gneisses, and the
+Ned Mountain Formation (Brock, 1989, 1993). Followed by a period of uplift and
+erosion. In New Jersey, metamorphosed rift facies rocks are mapped as the
+Chestnut Hill Formation of A. A. Drake, Jr. (1984)].
+~~~~~~~~~~~~~~~~~~~~~Surface of unconformity~~~~~~~~~~~~~~~~~~~~~ LAYER I -
+PROTEROZOIC BASEMENT ROCKS Many individual lithologic units including
+Proterozoic Z and Y ortho- and paragneiss, granitoid rocks, metavolcanic- and
+metasedimentary rocks identified, but only a few attempts have been made to
+decipher the stratigraphic relationships; hence, the three-dimensional
+structural relationships remain obscure. ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ [Grenville orogeny; deformation,
+metamorphism, and plutonism dated about 1,100 Ma. After the orogeny, an
+extensive period of uplift and erosion begins. Grenville-aged (Proterozoic Y)
+basement rocks include the Fordham Gneiss of Westchester County, the Bronx, and
+the subsurface of western Long Island (Queens and Brooklyn Sections, NYC Water
+Tunnel #3), the Hudson Highland-Reading Prong terrane, the Franklin Marble Belt
+and associated rocks, and the New Milford, Housatonic, Berkshire, and Green
+Mountain Massifs.] ~~~~~~~~~~~~~~~~~~~~~Surface of
+unconformity~~~~~~~~~~~~~~~~~~~~~ In New Jersey and Pennsylvania rocks older
+than the Franklin Marble Belt and associated rocks include the Losee
+Metamorphic Suite. Unconformably beneath the Losee, in Pennsylvania,
+Proterozoic X rocks of the Hexenkopf Complex crop out. Table 03 – Proposed
+new classification of the Pleistocene deposits of New York City and vicinity
+(Sanders and Merguerian, 1998, Table 2) REFERENCES CITED Baskerville, C. A.,
+1982, Adoption of the name Hutchinson River Group and its subdivisions in Bronx
+and Westchester Counties, southeastern New York: United States Geological
+Survey Bulletin 1529-H, Stratigraphic Notes, 1980-1982, Contributions to
+Stratigraphy, p. H1-H10. Benimoff, A. I., and Sclar, C. B., 1984, Coexisting
+silicic and mafic melts resulting from marginal fusion of a xenolith of
+Lockatong Argillite in the Palisades sill, Graniteville, Staten Island, New
+York: American Mineralogist, v. 69, nos. 11/12, p. 1005-1014. Bennington, J
+Bret, Forsberg, N., Schwager, K., and Verdi, E., 1997, Callianassid burrows and
+oyster accumulations in the Upper Cretaceous Navesink Formation, Central New
+Jersey: Paleoecological and sedimentological implications. Geological Society
+of America, Abstracts with Programs, vol. 29, no. 6, p. A100. Bennington, J
+Bret and Durso, Greg, 1999, The Cretaceous Flora of Long Island. American
+Paleontologist, vol. 7, no. 4, p. 2-4. Bennington, J Bret, Bonelli, J.,
+Chandler, J., and Selss, M., 1999, Paleoecological evidence for the formation
+of a backlap shell bed during maximum flooding, Upper Cretaceous Navesink
+formation, New Jersey: Geological Society of America, Abstracts with Programs,
+vol. 31, no. 7, p. A468. Berkey, C. P., 1948, Engineering geology in and around
+New York: in Creagh, Agnes, ed., Guidebook of Excursions: Geological Society of
+America, 61st Annual Meeting, New York City, p. 51-66. Brock, P. J. C., 1989,
+Stratigraphy of the northeastern Manhattan Prong, Peach Lake quadrangle, New
+York-Connecticut: p. 1-27 in Weiss, Dennis, ed., New York State Geological
+Association Annual Meeting, 61st, Field trip guidebook: Middletown, NY, Orange
+County Community College, Department of Science and Engineering, 302 p. Brock,
+P. J. C., 1993, Geology of parts of the Peach Lake and Brewster quadrangle,
+southeastern New York and adjacent Connecticut, and basement blocks of the
+north-central Appalachians: New York, NY, City University of New York Graduate
+Faculty in Earth and Environmental Sciences, Ph. D. Dissertation, 494 p., 6
+plates. Brock, Pamela Chase; Brock, Patrick W. G.; and Merguerian, Charles,
+2001, The Queens Tunnel Complex: a newly discovered granulite facies Fordham
+orthogneiss complex that dominates the subsurface of western Queens: p. 1-8 in
+Hanson, G. N., chm., Eighth Annual Conference on Geology of Long Island and
+Metropolitan New York, 21 April 2001, State University of New York at Stony
+Brook, NY, Long Island Geologists Program with Abstracts, 128 p. Carey, S. W.,
+1953, The orocline concept in geotectonics: Royal Society of Tasmania,
+Proceedings, v. 89, p. 255-288. deLaguna, Wallace, 1963, Geology of Brookhaven
+National Laboratory and vicinity, Suffolk County, New York: United States
+Geological Survey Bulletin 1156-A, 35 p. Drake, A. A., Jr., 1984, The Reading
+Prong of New Jersey and eastern Pennsylvania; an appraisal of rock relations
+and chemistry of a major Proterozoic terrane in the Appalachians, in
+Bartholomew, M. J., ed., The Grenville event in the Appalachians and related
+topics: Geological Society of America Special Paper 194, p. 75-109. Fedosh, M.
+S., and Smoot, J. P., 1988, A cored stratigraphic section through the northern
+Newark basin, New Jersey, p. 19-24 in Froelich, A. J., and Robinson, G. R.,
+Jr., eds., 1988, Studies of the early Mesozoic basins of the eastern United
+States: U. S. Geological Survey, Bulletin 1776, 423 p. Friedman, G. M., and
+Sanders, J. E., 1982, Time-temperature-burial significance of Devonian
+anthracite implies former great (~6.5 km) depth of burial of Catskill
+Mountains, New York: Geology, v. 10, no. 2, p. 93-96. (Also, reply to
+discussion, 1983, ibid., v. 11, no. 2, p. 123-124.) Friedman, G. M., and
+Sanders, J. E., 1983, Reply to discussion: Geology, v. 11, no. 2, p. 123-124.
+Fuller, M. L., 1914, The geology of Long Island, New York: U. S. Geological
+Survey Professional Paper 82, 223 p. Grauert, B.; and Hall, L. M., 1973, Age
+and origin of zircons from metamorphic rocks in the Manhattan Prong, White
+Plains area, southeastern New York: Carnegie Institute Annual Report for 1973,
+p. 293-297. Hall, L. M., 1968a, Times of origin and deformation of bedrock in
+the Manhattan Prong, p. 117-127 in Zen, E-an, White, W. S., Hadley, J. B., and
+Thompson, J. B., eds., Studies of Appalachian geology, northern and Maritime:
+New York, Wiley-Interscience, 475 p. Hall, L. M., 1968b, Trip A: Bedrock
+geology in the vicinity of White Plains, New York, p. 7-31 in R. M. Finks, ed.,
+New York State Geological Association, Annual Meeting, 40th, Queens College,
+Flushing, New York, Guidebook to Field Excursions, 253 p. Hall, L. M., 1976,
+Preliminary correlation of rocks in southwestern Connecticut, p. 337-349 in
+Page, L. R., ed., Contributions to the stratigraphy of New England: Boulder,
+CO, Geological Society of America Memoir 148, 445 p. Husch, J. M., 1990,
+Palisades sill: Origin of the olivine zone by separate magmatic injection
+rather than gravity settling: Geology, v. 18, p. 699-702. Hutton, James, 1795,
+Theory (sic) of the Earth with proofs and illustrations: Edinburgh, W. Creech,
+2 vols. Kay, G. M., 1951, North American geosynclines: Geological Society of
+America Memoir 48, 143 p. Leveson, D. J., and Seyfert, C. K., 1969, The role of
+metasomatism in the formation of layering in amphibolites of Twin Island,
+Pelham Bay Park, The Bronx, New York: in Larsen, L. H., Prinz, M., and Manson,
+V., eds., Igneous and Metamorphic Geology, Geological Society of America Memoir
+115, p. 379-399. Lewis, J. V., 1908a, Petrography of the Newark igneous rocks
+of New Jersey. Part IV, p. 97-167 in Geological Survey of New Jersey, Annual
+Report of the State Geologist for the year 1907: Trenton, New Jersey, The John
+L. Murphy Publishing Company, Printers, 192 p. Lobeck, A. K., 1939,
+Geomorphology. An introduction to the study of landscapes: New York and London,
+McGraw-Hill Book Company, Inc., 731 p. Long, L. E., 1969b, Whole-rock Rb-Sr age
+of the Yonkers gneiss, Manhattan prong: Geological Society of America Bulletin,
+v. 80, no. 10, p. 2087-2090. Manspeizer, Warren, 1980, Rift tectonics inferred
+from volcanic and clastic structures, p. 314-350 in Manspeizer, Warren, ed.,
+Field studies in New Jersey geology and guide to field trips: New York State
+Geological Association, 52nd, October 1980, Newark, New Jersey, Guidebook:
+Newark, New Jersey, Rutgers University, Newark College of Arts and Sciences,
+398 p. Merguerian, Charles, 1983a, Tectonic significance of Cameron's Line in
+the vicinity of the Hodges Complex - an imbricate thrust model for western
+Connecticut: American Journal of Science, v. 283, no. 4, p. 341-368.
+Merguerian, Charles, 1983b, The structural geology of Manhattan Island, New
+York City (NYC), New York: Geological Society of America Abstracts with
+Programs, v. 15, No. 3, p. 169. Merguerian, Charles, 1985, Geology in the
+vicinity of the Hodges Complex and the Tyler Lake granite, West Torrington,
+Connecticut, p. 411-442 in R. J. Tracy, ed., New England Intercollegiate
+Geological Conference, 77th, New Haven, Connecticut: Connecticut Geological and
+Natural History Survey Guidebook No. 6, 590 p. Merguerian, Charles, 1986, The
+bedrock geology of New York City: Abstracts with Programs, Symposium on The
+Geology of Southern New York, Hofstra University, p. 8. Merguerian, Charles,
+1987, The geology of Cameron's Line, West Torrington, Connecticut: in Roy, D.
+C., ed., Northeastern Section of the Geological Society of America, Centennial
+Fieldguide, p. 159-164. Merguerian, Charles, 1988, Annealed mylonitic textures
+in polyphase deformed metamorphic terrains: Geological Society of America,
+Abstracts with Programs, v. 20, p. A214. Merguerian, Charles, 1996c,
+Stratigraphy, structural geology, and ductile- and brittle faults of New York
+City, p. 53-77 in A. I. Benimoff and A. A. Ohan, chm., The Geology of New York
+City and Vicinity, Field guide and Proceedings, New York State Geological
+Association, 68th Annual Meeting, Staten Island, NY, 178 p. Merguerian,
+Charles, 2002, Brittle Faults of the Queens Tunnel Complex, NYC Water Tunnel
+#3, p. 63-73 in Hanson, G. N., chm., Ninth Annual Conference on Geology of Long
+Island and metropolitan New York, 20 April 2002, State University of New York
+at Stony Brook, NY, Long Island Geologists Program with Abstracts, 116 p.
+Merguerian, Charles; and Baskerville, C. A., 1987, The geology of Manhattan
+Island and the Bronx, New York City, New York: in D. C. Roy, ed., Northeastern
+Section of the Geological Society of America, Centennial Fieldguide, p.
+137-140. Merguerian, Charles; and Sanders, J. E., 1990c, Glacial geology of
+Long Island: Guidebook for On-The-Rocks 1990-91 Fieldtrip Series, Trip 15,
+17-18 November 1990, Section of Geological Sciences, New York Academy of
+Sciences, 96 p. Merguerian, Charles; and Sanders, J. E., 1991b, Geology of
+Manhattan and the Bronx: Guidebook for On-The-Rocks 1990-91 Fieldtrip Series,
+Trip 16, 21 April 1991, Section of Geological Sciences, New York Academy of
+Sciences, 141 p. Merguerian, Charles; and Sanders, J. E., 1991d, Geology of the
+Palisades and the Newark Basin: Guidebook for On-The-Rocks 1990-91 Fieldtrip
+Series, Trip 20, 26 October 1991, Section of Geological Sciences, New York
+Academy of Sciences, 83 p. Merguerian, Charles; and Sanders, J. E., 1991g,
+Geology of Cameron's Line and the Bronx Parks: Guidebook for On-The-Rocks
+1990-91 Fieldtrip Series, Trip 21, 24 November 1991, Section of Geological
+Sciences, New York Academy of Sciences, 88 p. Merguerian, Charles; and Sanders,
+J. E., 1992a, Xenoliths as indicators of paleoflow and paleoenvironmental
+conditions in the Palisades sheet, New York and New Jersey: Geological Society
+of America, Abstracts with Programs, v. 24, no. 3, p. 62-63. Merguerian,
+Charles; and Sanders, J. E., 1993d, Geology of southern Central Park, New York
+City: Guidebook for On-The-Rocks 1993 Fieldtrip Series, Trip 28, 26 September
+1993, Section of Geological Sciences, New York Academy of Sciences, 143 p.
+Merguerian, Charles; and Sanders, J. E., 1994b, Post-Newark folds and -faults:
+implications for the geologic history of the Newark basin, p. 57-64 in Hanson,
+G. N., chm., Geology of Long Island and metropolitan New York, 23 April 1994,
+State University of New York at Stony Brook, NY, Long Island Geologists Program
+with Abstracts, 165 p. Merguerian, Charles; and Sanders, J. E., 1994f,
+Implications of the Graniteville xenolith for flow directions of the Palisades
+magma: p. 59 in A.I. Benimoff, ed., The Geology of Staten Island, New York,
+Field guide and proceedings, The Geological Association of New Jersey, XI
+Annual Meeting, 296 p. Merguerian, Charles; and Sanders, J. E., 1995a, Late
+syn-intrusive clastic dikes at the base of the Palisades intrusive sheet, Fort
+Lee, NJ, imply a shallow (~3 to 4 km) depth of intrusion: p. 54-63 in Hanson,
+G. N., chm., Geology of Long Island and metropolitan New York, 22 April 1995:
+Stony Brook, NY: Stony Brook, NY, Long Island Geologists Program with
+Abstracts, 135 p. Merguerian, Charles; and Sanders, J. E., 1995b, NE-, not SE-,
+directed paleoflow of the Palisades magma: new evidence from xenoliths and
+contact relationships: p. 64-77 in Hanson, G. N., chm., Geology of Long Island
+and metropolitan New York, 22 April 1995: Stony Brook, NY: Stony Brook, NY,
+Long Island Geologists Program with Abstracts, 135 p. Merguerian, Charles; and
+Sanders, J. E., 1996a, Diversion of the Bronx River in New York City - evidence
+for postglacial surface faulting?: p. 131-145 in Hanson, G. N., chm., Geology
+of Long Island and metropolitan New York, 20 April 1996, State University of
+New York at Stony Brook, NY, Long Island Geologists Program with Abstracts, 177
+p. Merguerian, Charles; and Sanders, J. E., 1997, Bronx River diversion:
+neotectonic implications (abs.): Paper No. 198, p. 710 in Hudson, J. A. and
+Kim, Kunsoo, eds., International Journal of Rock Mechanics and Mining Sciences,
+Special Issue, 36th U.S. Rock Mechanics Symposium, Columbia University, New
+York, June 29-July 02, 1997, v. 34, no. 3/4, 714 p. Full version on CD-ROM, 10
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+igneous activity in the Manhattan Prong, southeastern New York: Geological
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+possibly four) glaciations from two directions (NNE to SSE and NW to SE):
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+40 p. Sanders, J. E.; and Merguerian, Charles, 1992a, Directional history of
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+metropolitan area, SE NY: Geological Society of America, Abstracts with
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+geology of New York City and vicinity: p. 93-200 in A. I. Benimoff, ed., The
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+Washington Deltas" of Woodworth (1901) revisited: pre-Woodfordian Gilbert-type
+delta revealed in storm-eroded coastal bluff, Sands Point, New York: Geological
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+Filename: 1CManual0209.htm