NYSGA

2: THE "AGE OF DINOSAURS " IN THE NEWARK BASIN, WITH SPECIAL REFERENCE TO THE LOWER HUDSON VALLEY
Paul E. Olsen and Emma C. Rainforth
Lamont-Doherty Earth Observatory
Palisades, NY
ABSTRACT
This field guide is intended as an introduction to the rich stratigraphic and paleontological record of the Triassic-Jurassic Newark rift basin, especially in the vicinity of the present and ancestral routes of the lower Hudson River. We will visit seven stops that illustrate this region's range of sedimentary and igneous environments and paleobiological assemblages, focusing on their significance to the understanding of global events in the early Mesozoic, in particular the beginning of the "Age of Dinosaurs".
INTRODUCTION
The Newark basin (Figure 1) is one in a remarkable series of early Mesozoic rift basins that extend from Greenland to Europe, Morocco and eastern North America, and to the Gulf of Mexico, comprising the largest known rift system. This massive set of basins - the central Atlantic margin rifts - formed during the crustal extension that led to the fragmentation of Pangea (Figure 1). The Newark basin is one of the largest segments of the outcropping, deeply eroded North American contingent of these rifts, the basin fill of which is collectively termed the Newark Supergroup (Figure 1). Continental rifting seems to have begun in eastern North America sometime in the median Permian and finished in the Early Jurassic, although the exact timing of the termination of rifting is poorly constrained. These rifts - in particular the Newark basin - also record a major tectonic paroxysm that punctuated the beginning of the Jurassic: the emplacement of basaltic intrusions and extrusions of the Central Atlantic Magmatic Province (CAMP) (Marzoli, 1999; Olsen, 1999) - the largest known igneous province (Figure 2).
A “Hot House” mode of global climate system apparently prevailed during the Triassic and Early Jurassic, with little or no convincing evidence of ice at the poles, probably due to very elevated CO2 levels (Ekart and Cerling, 1999; Tanner and Hubert, 2001). Despite the profound difference between today’s global climate and that of the early Mesozoic, tropical climate gradients, as reflected by indicators of humidity, were evidently not much different than today – and hence quite strong (Kent and Olsen, 2000). During this time, Pangea straddled the equator, its central region drifting slowly northward through time (Figure 2). The Newark basin lay in this central region, and drifted from an equatorial position in the late Middle Triassic or earliest Late Triassic (~232 Ma) to about 7°N by the beginning of the Jurassic (~202 Ma). As a consequence, the Newark basin itself slowly drifted from the wet tropics through a strong climate gradient towards the arid climate belt, producing a sedimentological transition that is well displayed in the basin sediments.
Within this context of the Early Mesozoic “Hot House” world, climate was far from stable in the tropics. As is true for tropical climate during the Quaternary, that of the Triassic and Early Jurassic fluctuated dramatically in precipitation following Milankovitch climatic cycles, driven by variations in the Earth’s orbit. These precipitation and evaporation cycles are recorded as lake level cycles of several orders of complexity in the abundant Newark Supergroup lacustrine deposits, and especially in the Newark basin (described in more detail below). In addition to providing a constantly fluctuating sedimentary environment sampling various lacustrine to fully terrestrial biological communities, these cycles provide a rigorous stratigraphic framework for the basins and a mechanism by which to calibrate the Late Triassic-Early Jurassic time scale.
Biologically, the Triassic and Early Jurassic were pivotal. The early Mesozoic opened following the largest mass-extinction of all, that of the end-Permian. However, terrestrial communities of the Early Triassic largely inherited the Paleozoic-style dominance of synapsid amniotes (the oxymoronic “mammal-like reptiles”), and very distinct northern and southern hemisphere floras. Through the Triassic, however, diapsid sauropsids (lizards, crocodilians, dinosaurs and their relatives) became progressively more abundant, diverse, and larger, so that by the beginning of the Late Triassic synapsids were rare in tropical regions, except for a narrow belt around the equator. By the early Late Triassic dinosaurs had evolved, but they did not become truly dominant until after the next great mass extinction at the Triassic-Jurassic boundary. This great transition to dinosaurian dominance is recorded in detail in Newark Supergroup and particularly Newark basin deposits, as explored in this fieldtrip guide.

2: THE "AGE OF DINOSAURS " IN THE NEWARK BASIN, WITH SPECIAL REFERENCE TO THE LOWER HUDSON VALLEY

Outcrops of diabase and hornfels of Lockatong-like facies.

Ancestral Hudson River
Crossing buried valley of ancestral (Miocene-Pleistocene) Hudson River.

On right is the Blauvelt footprint site
On right is the Blauvelt footprint site discovered in 1972 by PEO and Robert F. Salvia. Site consists of the excavated dip slope of gray, tan, pink, purple, and red mudstones and sandstones of the Stockton Formation equivalent of the Lockatong Formation.
Tracks found include a slab of tridactyl footprints often attributed (incorrectly we believe) to the ceratosaurian theropod dinosaur Coelophysis (e.g. Fisher, 1981), and isolated tridactyl tracks (Figures 15, 16). These tracks are rather broad and tulip-shaped suggestive of large Atreipus (see mileage 34.8 and Stop 6), the early ornithischian dinosaur ichnite. However definitive manus impressions are lacking, and they tend to be broader than most Atreipus. They could belong to a new form, but because of their overall poor preservation, they remain indeterminate.
Other footprint forms found are largely indeterminate but include indeterminate forms that are probably poorly preserved examples of small Brachychirotherium as well as an example of Rhynchosauroides cf. R. hyperbates (Figure 15). Indeterminate phytosaur teeth and bone scraps occur in the footprint-bearing beds.
On the south side of the exposures are greenish and tan mudstones with abundant and often large roots and tree trunk casts suggestive a strongly vegetated surface (Figure 15).

Outcrop on right is Palisade sill
Outcrop on right is Palisade sill that has moved considerably higher in the section to the Stockton-Passaic formational boundary.

Pass Lone Star quarry on left
Pass Lone Star quarry on left in a large apophysis of the Palisade sill.

Palisade sill moves lower in section in this area.

Dip slope of Palisade sill.

Long Clove Quarry in Palisade sill on left.

Pass through small fault gap
Pass through small fault gap to the front of the cuesta of the Palisade sill.

Outcrops on left are of red sandstones of Stockton facies.
As we travel north the contact with sill drops discordantly lower in the sedimentary section.

Strike ridge of Palisade sill curves strongly to the west.

Crossing Cedar Pond Brook

STOP 1. Gorge of Cedar Pond Brook, Stony Point, New York.
STOP 1. Gorge of Cedar Pond Brook, Stony Point, New York. Latitude and Longitude: 41°13.605', 073°59.079 ' to 41°13.677', 073°59.378
Tectonostratigraphic Sequence: TS III
Stratigraphic Unit: ?lower Passaic Formation
Age: Late Carnian (early Late Triassic); ~220-223 Ma
Main Points:
1. NE terminus of Newark basin near onlap onto basement of TS III
2. Sediment-starved section with well-developed carbonate beds
3. Carbonates of ?lacustrine and pedogenic origin - local source
4. Should be ideal area for bone or egg preservation
5. Relevant to arguments about the Broad Terrane Hypothesis
Cedar Pond Brook flows from west to east cutting a gorge though a unique carbonate-rich facies of the Newark basin section at its northern terminus (Figures 17, 18). The western, coarse-grained part of the section was mentioned by Ratcliffe (1980) and described in outline (with thin sections) by Sanders (1974), but is otherwise virtually unstudied.
Conglomerates making up the basal beds of the local section outcrop to the east in a railroad cut within the Stony Point Battlefield Park (Figure 17). Basement here consists of metamorphic rocks bordering the Cortland Complex, which is locally reddened near the contact with the conglomerate. The contact itself is not exposed. According to Ratcliffe (1980), the exposed conglomerates contain clasts of Manhattan Schist and Ordovician Inwood Marble dolostone clasts, both clast types being derived very locally from the east and north. The section fines to the west, passing up-section into a cyclical sequence of red calcareous mudstones and sandstones and pink to gray limestones (Figures 19, 20).
Cycles have a mode about 1.5 m with a large amount of variation consist of a lower red silty mudstone with abundant Scoyenia burrows and root traces, passing upward into mudstone with carbonate nodules; these nodules often coalesce upward into a bed of pink to white massive limestone (Figure 20). The limestone contains thin (~2 mm) branching tubes that are most likely root traces, but sometimes also (apparently) ostracodes, identified in thin section by Sanders (1974). These biologic remains indicate that at least some of the limestones are of lacustrine origin, perhaps modified by pedogenic structures. Many of the mudstones and limestone beds have large (~1 m long, ~3 cm wide) root traces and most mudstones have densely branching thin root traces.
Strikingly absent from these outcrops are larger-scale fluvial units such as channels. However, also absent are any indications of Van Houten cycles, unless they are the limestone cycles themselves. This facies resembles no others in this part of the basin, although it does bear some similarity to the middle upper Passaic of the Jacksonwald syncline, where carbonate beds are well-developed (although not as well-developed as here). This suggests that this section represents a relatively dry phase of a McLaughlin cycle, probably in the lower Passaic Formation, in an area of the basin isolated from entry points of major rivers or streams.
Ratcliffe (1980) described the "Annsville Phyllite", present to the west on the hanging wall of the Ramapo fault system (here the Thiells splay). Sedimentary breccias of (?)Inwood Marble carbonate occur locally near the fault low in the section on the north side of the Cedar Pond Brook gorge. This indicates that there was indeed a local source of abundant carbonate, which probably accounts for the extreme development of limestone beds in this facies.
Recently, it has become clear that tetrapod remains are present and locally abundant, being well preserved at many levels within the Newark Supergroup in red massive sandy to silty mudstones which contain root traces and have variable development of carbonate nodules and caliches (Carter et al., 2001; Olsen et al., 2000b, 2001b; Sues et al., 2000). The abundance of carbonate helps to buffer bone dissolution in a pedogenic environment, and can allow otherwise very perishable vertebrate carbonate fossils - eggs - to be preserved. The association of pedogenic carbonate nodules (caliche or Kunkar) and tetrapod bone has been repeatedly noted elsewhere (e.g. Dodson et al., 1983). These outcrops should be ideal for bone preservation, but there has been little prospecting as of yet. Persistence is needed, however, because the tetrapod fossils tend to be nearly the same color as the carbonates, making it very difficult to locate.
This northeastern part of the Newark basin was crucial to Sanders (1960, 1963, 1974) arguments for the "Broad Terrane Hypothesis". This hypothesis was first proposed by I.C. Russell (1879, 1880), who argued that the Newark and Hartford half-graben basins were actually the western and eastern components of a giant full graben which had been post-depositionally uplifted in the middle and then deeply eroded (Figure 21). Sanders considered the northeastern terminus of the Newark basin to be a key area because it showed that this end of the basin was an artifact of post-deposition folding, indicated by the basement-parallel strike of the beds wrapping around to the west, towards the border fault. Sanders argued that there is no indication of onlap of progressively younger strata onto basement to the northeast; therefore the basin did not shallow in that direction, and the high between the basins did not exist at the time of deposition.
We argue that these outcrops favor exactly the opposite interpretation. There is no evidence at all that the sequence seen at Stops 1-4 is the basinward equivalent of the basal section (i.e. Stockton Formation) of the Newark basin. The facies is utterly unlike the local expression of the Stockton, and all the evidence (as seen in stops 2-4) points to a shoaling of the basin towards the north and east. In addition, the map pattern (7, 13) indicates rapid thinning of the Passaic Formation toward this area and dramatic changes in strike, both of which are consistent with the existence of a syndepositional basin high in the region between the Newark and Hartford basins.
However, this does not mean that there might not have been a sedimentary connection between the two basins. The Newark and Hartford basins are deeply eroded, and if TS III in eastern North America follows the pattern seen in the much less deeply eroded Moroccan basins, we should expect there to have been onlap of the younger parts of TS III over basement, eventually connecting the two basins. Strata of TS IV, particularly the basalt flows and thinned interflow units, may also have connected the basins (c.f. McHone, 1996). It is also quite likely that considerable amplification of the high between the two basins occurred post-depositionally as a consequence of late Early Jurassic to Middle Jurassic tectonic inversion. However, there is no evidence supporting the argument that the deepest part of the combined Newark-Hartford basin lay in the now-uplifted region between them, as proposed in Russell's and Sanders' versions of the Broad Terrane Hypothesis.

STOP 2. West shore of Hudson River, Palisades Interstate Park, Haverstraw, New York
Park at south termination of Riverside Avenue in parking lot for Hook Mountain State Park of the Palisades Interstate Park. Walk south along path about 1060 m looking for ruins on left. Turn left at ruins and (carefully!) proceed down the rocky and vegetated slope to Stop 2.
Tectonostratigraphic Sequence: TS III
Stratigraphic Unit: Stockton Formation
Age: Late Carnian (early Late Triassic); ?220 Ma
Main Points:
1. Stockton-like equivalent of Lockatong Formation at basin edge
2. Fluvial and ?lake margin facies of wet part of McLaughlin cycle
3. Multiple fossil-rich facies
4. Sampling of more terrestrial communities than usual for this time
5. Well-preserved footprints in unusual settings
6. Relatively abundant bones in tan quartz-pebble conglomerate
Abundant outcrops and exposures below the Palisade sill extend from Haverstraw, New York south to Hoboken, New Jersey allowing a close look at the facies changes along-strike progressing from mostly-fluvial environments in the northeast to the mostly lacustrine cyclical facies in the southwest. Outcrops along the west shore of the Hudson River in this segment of the Palisades Interstate Park consist mostly of various fluvial facies with some hints of lacustrine influence. This site consists of exposures in a small abandoned quarry and river-side outcrops of a ~17 m thick section of very heterogeneous clastic rocks, including tan quartz-pebble conglomerates, pink and red sandstones, and purple and red mudstones and siltstones (Figures 22, 23, 24).
Evidence for this section being the along-strike equivalent of the lower part of the Lockatong (probably the Nursery or Ewing Creek member) consists primarily of the apparent continuity of strike direction from unquestionable Lockatong outcrops to the south of this region. If there is some hanging wall onlap of younger strata onto basement in this direction - and there is a hint of this - these outcrops would still likely be part of the Lockatong rather than lower in the section. In addition, the facies change northwards along-strike from the Lockatong is slow, consistent, and significantly different from the lateral change within the Passaic Formation in the same region that trends towards exclusively red conglomerates.
The abundance of tan, pink, and purple strata at this section (Figure 24) suggests prolonged water saturation of the sediments prior to lithification, and, together with the relatively muted pedogenic influences, suggests deposition during a relatively wet episode. The thickness scale of the section showing these features suggests perhaps a wet phase of a 404 Ky. cycle as is also expressed in the Lockatong Formation to the south (e.g. Stops 4 – 6). However, it is important to note that we have no direct knowledge of the scale of depositional relief (e.g. of marginal deltas), nor is there a clear indication of a hierarchy of cycles, so this interpretation has to be regarded as tentative.
What makes this site particularly interesting is the relative abundance of tetrapod fossils in virtually all lithologies. Most of the fossils are found right at the Hudson shoreline, where rubble piles from the old quarry are eroding into the river, providing clean and fresh rock faces for examination. It is well worth pulling material directly from the eroding rubble piles, as well as turning over slabs in the river itself.
The lithology most consistently producing bones is a tan quartz-pebble conglomerate. Bones and teeth are white in this matrix and comparatively easy to see. Blocks of this material should be broken up to hand-size pieces to reveal fresh faces before being discarded. Thus far, a small partial (?)skull (as yet unprepared; Figure 25), an amphibian dermal bone, numerous (?)phytosaur teeth, and many unidentified bone and teeth fragments have been found. Red and purple siltstones and sandstones have also yielded white bone and tooth scraps, so these lithologies should also be carefully examined.
Reptile footprints are surprising common at this site and occur in a variety of lithologies, showing nearly the full range of footprint preservational styles (Figure 26). Perhaps the most unusual style of preservation is in a red to dark reddish-purple medium-grained sandstone, in which the tracks are preserved as sometimes high-relief natural casts on the underside of beds, frequently preserving skin impressions and other exceptional details. The tracks are actually impressions in a thin massive silty claystone which crumbles when the overlying sandstone is separated. Tracks are also found as lower-relief natural casts and impressions in flaggy sandstones and siltstones, as faint underprints, and as leptodactylous forms (Figures 25, 26). The group name Leptodactyli ("thin-toed") was introduced by Edward Hitchcock (1836) for what he regarded as a major subdivision of tracks. In fact such tracks are extremely interesting traces representing one end-member of preservational style, that record the implantation and extraction of a foot in deep (relative to the foot size), soft, usually ripple cross-laminated silt or very fine sandstone. The substrate must have been water-saturated at the time of impression, and probably not bound by micro-organisms such as algae. Gatesy et al. (1999) was (to our knowledge) the first to recognize the true nature of these traces and to extract useful information about trackmaker locomotion from them. The hallmarks of the leptodactylous style of impression is that the “soles” of the toes appear sharply pointed or creased in cross-section, the impression passes through many layers, and on each layer the track has a different shape. This style of track can be extremely abundant where ripple cross-laminated siltstones are present, and while they have great potential to understand locomotory mechanics, they provide little information on the identity of the trackmaker, and sometimes lead to spurious interpretations (e.g. the supposed presence of feathers at the back of the feet).
Thus far, Rhynchosauroides cf. R. hyperbates, Apatopus lineatus, Brachychirotherium cf. B. eyermani, and cf. Atreipus and other indeterminate dinosaurian tracks have been found at this locality, which is one of the oldest footprint assemblages in the Newark basin. Associated with the Rhynchosauroides cf. R. hyperbates are crisscrossing scratch marks of the appropriate size to have been made by the same track maker (Figure 25). Similar scratch marks arranged in crescent-shaped arrays occur associated with Rhynchosauroides at other localities (Olsen et al., 1989), and have even been interpreted to be the tracks of a hairy cynodont (Ellenberger, 1976). These scratch traces are almost certainly all foraging traces of reptiles. A striking feature of this and all of the older track localities in the Newark Supergroup (see mileage 34.8 and Stop 6) is that dinosaurian tracks are not common and all are relatively small.
Lockatong Formation fossil assemblages tend to be very stereotyped, almost entirely biased toward preservation of aquatic forms (unsurprising given the dominance of lacustrine facies). Thus this type of assemblage, from fluvial facies (i.e. Stockton Formation) of Lockatong age , is very important, in that it provides a sampling of a more terrestrial assemblage for Lockatong time. Careful further prospecting at this site and others along the Hudson, should provide much more information.

Tunnel for Penn Central Railroad.
Western portal has outcrops of tans sandstones and dark gray hornfels. Contact with sill is strongly discordant and was figured by Kümmel (1899).

Cut through discordant limb of Palisade sill.

Exposures behind Volkswagen repair shop
Exposures behind Volkswagen repair shop are of tan, gray, and red sandstone. Reptile tracks occur in well-bedded gray siltstones. Tracks include Grallator cf. G. paralellum (sensu Olsen et al, 1999) and Brachychiroptherium sp. (Figure 15). Tan sandstone beds with shale chips and carbonate bleb lags have scales of Turseodus and indeterminate small tetrapod bones and teeth.

To north is Hook Mountain State Park
To north is Hook Mountain State Park with outcrops of the Palisade sill and underlying Stockton Formation briefly described by Sanders (1974).

Overpass for New York State Thruway
Overpass for New York State Thruway and west portal of the Tappan Zee bridge. Borings for the bridge identified the Stockton-basement contact in the Hudson (Figures 7, 13) (Sanders, 1974).

Brownstone Quarries, Grandview, New York
A string of small- to medium-sized quarries were developed during the 19th and early 20th centuries in red clastics below the Palisade sill, from just south of the present position of the west ramp for the Tappan Zee Bridge in South Nyack, to northern Piermont. These quarries all seem to have exploited the same facies of red fluvial sandstone and mudstone. Much of this distinctive bright red-orange-brown sandstone was used for the construction of buildings in Nyack and homes in Grandview. Most of these quarries now contain private homes.
The sections exposed in these quarries consists of fluvial sequences, much of which are heavily bioturbated by roots and burrows. Several moderate sized channels are exposed. The abundance of pedogenic structures, and the lack of drab colored beds indicative of long-term water saturation, suggest that this facies is within a dry phase of a 404 Ky. (or longer) cycle. In support of this, the belt of red clastics progressively rises in elevation to the south and is underlain by a bench of drab coarser-grained clastics that also rises in elevation southwards to central Piermont, where it is exposed along River Road and Ash Street. However, the lower contact of the Palisade sill does not change elevation significantly over the same area. Therefore the contact between the sill and the country rock becomes stratigraphically lower to the south: the sill rests above a thick section of red clastics at Grandview (this Stop), but rests on the afore-mentioned tan sandstones at Piermont. This relationship could also be taken as evidence of onlap of younger strata to the north, but it might instead be due to a slight rise in the position of the Palisade sill, shifting the topographic high to the west.
According to Lawrence Blackbeer (pers. comm., 2001) tracks were recovered in these quarries by a quarry operator. They were sold to Blackbeer, and subsequently sold at Phillips auction house in New York City. ShayMaria Silvestri (Rutgers University) was kindly allowed to photograph these specimens; her photographs are reproduced here (Figure 27). The slabs reveal well-preserved unquestionable examples of large Atreipus milfordensis and Brachychirotherium cf. B. eyermani, the latter preserving skin impressions. The former are remarkably similar to specimens from the middle Passaic at Stop 6 of this field trip, also in the Blackbeer collection. Atreipus has also been described from an in situ occurrence in the Lower Lockatong Formation at Arcola, Pennsylvania (Olsen and Baird, 1986). The track-bearing layers have not as yet been identified at the present locality. As far as we know, these quarries have never been carefully prospected; additional searching could reveal important new material. Because all of these sites are privately owned and residential, permission to prospect must be sought in every case, with due care given to private property and privacy.

Outcrop of tan arkose and gray and purple mudstone on right.

Arkose and gray mudstone and contact with Palisade sil
Outcrops of tan arkose and gray mudstone and contact with Palisade sill are on northwest corner of Ash and Kinney streets. The red clastics seen in the Grandview quarries to the north are evidently at a higher stratigraphic level

Sparkill Creek flows through Sparkill Gap
Sparkill Creek flows through Sparkill Gap, which is where the ancestral Hudson River deviated from its present course and headed south west though the Palisade cuesta.

Turn left up dip slope of Palisade sill.

Turn right onto 9W south following the strike ridge of the Palisade sill.

STOP 3. Along-strike transect, Palisades Interstate Park, Alpine to Edgewater, New Jersey.
Tectonostratigraphic Sequence: TS III
Stratigraphic Unit: Lockatong and Stockton formations
Age: Late Carnian (Early Late Triassic); 225-226 Ma
Main Points:
1. Lateral transition from Stockton to Lockatong formations at basin edge
2. Marginal to deep-water lacustrine environments
3. Well-developed Van Houten cycles appear
4. Van Houten cycles very thin at hinge margin
5. Two cycles traced through basin with distinctive faunal patterns
6. Palisade sill as part of the CAMP event
7. Intrusion-related structures and sill contact
8. Distinctive facies of Stockton Formation with bones
Lockatong and Stockton sediments and their contacts with the Palisade sill are exposed at numerous places along the Palisade escarpment from Hoboken, New Jersey to Haverstraw, New, and permit a cycle-by-cycle correlation of the Lockatong for at least 15 km of this distance. The individual cycles were informally designated a series of letters and numbers (Olsen, 1980; Figure 28). Exposures in the Palisades Interstate Park, along Henry Hudson Drive and the Hudson River shore, from the Alpine boat basin to the park's entrance off of River Road in Edgewater, provide one of the best places to examine the lateral facies changes in the lower Lockatong and Stockton formations in northeastern New Jersey. In this along-strike transect we will have three mini-stops and five more significant stops (Figures 29, 30).

Ministop 3a: Stockton Formation entrance to Alpine Boat basin:
Tan and purple arkose with large-scale cross-bedding, and red and dark purple mudstone is exposed along the west side of Henry Hudson Drive and the traffic circle at the south end of the Alpine boat basin. Trough cross-bedding seems to dominate, with paleocurrents heading generally south and west. Given that this outcrop is near river level, it is more likely to be the lateral equivalent of those parts of the Stockton Formation fluvial sequence seen at Stop 3g (see below), rather than a lateral equivalent of the Lockatong Formation as seen at higher elevations (Stops 3b-3f). However, the strata also resemble the outcrop passed at Ash Street in Piermont (NY), which is probably the lateral equivalent to some of the Lockatong levels at Stop 3g.
To the north of the circle is the Alpine Boat Basin and the Blackledge-Kearny House. From the Blackledge-Kearny House (often reported as the headquarters of Cornwallis' assault on Washington's garrison), north there are excellent outcrops of the Stockton Formation very similar in facies to what is seen to the south, notably at Stop 3g. To our knowledge these have not been prospected for vertebrates, or studied.

Cross bedding in Lockatong-Stockton lateral transitional facies along road;
Currents heading south.

Another small outcrop of cross bedded tan arkose
Another small outcrop of cross bedded tan arkose of the Lockatong-Stockton lateral transitional facies

STOP 3b.: Lockatong-Stockton lateral and vertical transitional
Greenbrook Falls, Alpine, New Jersey
A shear cliff at the waterfall for Green Brook Creek and adjacent exposures on the west side of River Road reveal a long vertical section of the lower Lockatong and underlying Stockton formations. This is the only outcrop of this vertical transition known. Unfortunately, apart from the exposures along the road, the waterfall outcrops are virtually inaccessible and very dangerous. Note that climbing is NOT permitted in the park.
The roadside exposures show a small anticline in the still-cyclical lower Lockatong Formation (Figure 31). Here the cycles are considerably thicker than further south along the Hudson, and it is possible that these beds are part of a deltaic complex, changing laterally into the Stockton Formation. Here, each cycle averages about 4 m thick (N=2: Figure 32), consists of a gray massive to faintly parallel-bedded mudstone, overlain by crudely-bedded, locally cross-bedded and oscillatory-rippled tan arkose. These cycles do not show any hint of micro-lamination and vertebrate fossils have yet to be found. If the gray mudstones were slightly thinner and the irregularity of the bedding increased, this outcrop would be indistinguishable from some of the nearby units mapped as Stockton Formation. These units are probably the lateral equivalents of part of the Nursery or Princeton members at Stop 3c (below).
The anticline could be due to deformation caused by emplacement of the Palisade sill. More likely, it represents bedding distortion caused by modest gravity sliding along depositional relief at the lateral terminus of the Lockatong lake system.

Exposures of dark gray hornfels of laminated mudstone
Exposures of dark gray hornfels of laminated mudstone that appears to be part of cycle W6. At this outcrop the burrow Scoyenia penetrates the mudstone, consistent with a stronger surface modification and a nearshore environment.

STOP 3c. Van Houten cycles of lower Lockatong Formation
These exposures comprise a long section though most of the Nursery and Princeton members at the northernmost outcrops at which these members can be unambiguously identified (Figures 29). This site has been previously described by Olsen (1980) and Olsen et al. (1989). We will begin at the north end of the exposure and proceed south, going up-section (Figure 33).
The series of Van Houten cycles in the Nursery and Princeton members of the Lockatong Formation are among the most distinctive in the entire Newark basin (Figure 34). Not only do they present a specific sequence of distinctive lithologies, but the faunal content of the cycles and the vertical changes in faunal composition is distinctive and persists laterally for at least 150 km (Figure 35). Two cycles in particular, - cycles W5 and W6 - are the lynchpin for the lateral correlation. These two cycles were quarried extensively at outcrops in Weehawken, New Jersey by a team from Yale University in 1979 and 1980 (Olsen, 1980) (Figure 36). More than 3000 specimens of fish and reptiles were recovered, resulting in a detailed sampling of faunal and taphonomic change through the two cycles (Figure 37, 38, 39). At Weehawken, the lower cycle (W6) has a very fine-grained clay-rich partially-microlaminated division 2. Articulated specimens of the tanystropheid Tanytrachelos ahynis are present in the transitional beds leading into the microlaminated portion of this division. However, most of the microlaminated portion of this cycle is dominated by the holostean fish Semionotus braunii, which was originally described by Gratacap (1886) and Newberry (1888) from a small exposure to the north of the Yale Weehawken excavations, although other fish are present - notably articulated specimens of the small coelacanth Osteopleurus newarki, which are relatively common in the upper part of the microlaminated interval. Division 3 is distinctive in that the lower part has a distinct interbed that marks a return to perennial lake conditions. This makes W6 appear as though it has a double division 2. This is characteristic of Van Houten cycles near the paleoequator, because there are two insolation maxima per 20 ky near the equator, rather than one, due to the twice-annual passage of the sun over the equator (Crowley et al., 1992; Olsen and Kent, 2000). Many Newark basin Van Houten cycles show hints of this pattern consistent with the basin’s near-equatorial position, but none show it as strongly as cycle W6. Interestingly, this deeper water interbed has a different dominant fish - the palaeoniscoid Turseodus - represented, however only by disarticulated, albeit distinctive, elements.
The succeeding cycle, W5, has disarticulated rare Semionotus at its very base, associated with abundant disarticulated elements of the bizarre drepanosaurid diapsid Hypuronector limnaios (Colbert and Olsen, 2001) (Figures 8, 39), Above this, articulated Osteopleurus occur, but higher up, articulated Turseodus dominate the microlaminated interval. The microlaminated interval contains metamorphic minerals (e.g. diopside) that show that the laminite was much more calcareous than that of cycle W6. Virtually all of these features persist laterally from Weehawken northward to this stop (Figure 37).
Cycles W5 and W6 have also been identified in the NBCP cores and in outcrops in the southwestern part of the basin. Because of the distinctiveness of these two cycles, the correlation of the adjacent cycles is certain, and the pattern of cycles as well as their constituent fauna is maintained across much of the basin (Olsen at al., 1996a).
In contrast to sections further south that contain these cycles, this section contains the largest proportion of tan arkose, most notably in many of the shallow-water portions of the Van Houten and short modulating cycles. Much of this tan arkose exhibits oscillatory ripples, especially in division 1 of the cycles. Compared to sections further south, it is clear that the dry phases of the short modulating and McLaughlin cycles are abbreviated, with some parts even omitted (Figure 35). In addition, the degree of lamination is generally less. The average thickness of the Van Houten cycles at this stop is about 1.5 m. This is only about 25% of their thickness in the central Newark basin, and is consistent with the position of this section on the shoaling, hinge side of the basin.
On the whole, the distribution of vertebrate remains is consistent with stratigraphic equivalents further south, although the degree of articulation is less at this stop. In all cases at these exposures, bone and scale material is preserved as a translucent milky or pinkish phosphate, making it difficult to see. Combined with the extreme hardness of the metamorphosed sediment, this makes finding vertebrate material very difficult at this locality - although good specimens are present and can be found.
The underlying cycle, Wa is penetrated by numerous Scoyenia burrows (which were definitely not present at Stop 4) as are cycles Wb and Wc. We are clearly in the shallow-water facies of division 2 of cycles Wa-c at this point, but only just leaving the deep-water facies of division 2 in cycles W2, W5, and W6. Cycle Wa shows well developed fracture cleavage in division 1. This cleavage dips 25° - 30° and strikes S78°W. It is strata-bound but discontinuous, passing laterally into breccia or non-cleaved beds. What is the significance of these structures?
The tongue of buff arkose between cycles W6 and Wa is thinner than at Stop 4 and displays unidirectional, oscillatory, and possibly hummocky cross-stratification, suggesting wave reworking of sheet deltas. Division 2 of cycle Wa is cut out by the arkose beds of this sequence by a channel-fill sandstone with mudcracked mudstone interbeds. Mean paleocurrent direction for these cross-beds is N59°W (based on 8 readings) (Figure 34).
In cycles W5 and W6 the degree of micro-lamination is significantly less than in these cycles further to the south, consistent with the rest of the section, significantly so in W5. The sequence of vertebrate taxa is still consistent with the pattern seen at Weehawken, but the degree of articulation has decreased. However, articulated Tanytrachelos and Semionotus are still present in division 2 of cycle W6. The upper part of division 1 of W6 has produced a partial arthropod, of uncertain relationships, about 20 cm long (Olsen, 1980). The most dramatic change from outcrops to the south, however, is that in this area, nodules, probably originally of carbonate, increase upward from the microlaminated portion of division 2 of cycle W6, coalescing into a nodular bed in the lower part of division 3, just below the more-laminated bed within division 3 that is such a distinctive feature of this cycle (Figures 34, 40). We interpret this nodular ?former carbonate level as a caliche, developed in the dry lakebed of the lower parts of cycle W6. Hints of this caliche begin to appear in outcrops to the south (Figure 37).
Cycles 3 and 4 are evidently replaced by wave-influenced buff, cross-bedded arkose. Cycle 2 is very well exposed and contains the fish Turseodus and Diplurus. Cycle 1' is present, overlain by 4 m of arkose, but there is no sign of cycle 0, which presumably has pinched out or was cut out south of here. Cycle 1 is present but poorly exposed.
The facies trend in the Lockatong Formation from Stops 3 to 5 is from a basin-margin facies to a more central basin facies. The lateral heterogeneity seen toward the basin's hinge margin [Stops 3-5] gives way to monotony in horizontal continuity to the south. Those cycles with the best developed microlaminae and the best preserved fish at this stop are also those which persist the furthest laterally with the least change.

Ministop 3d. Abandoned quarry in Palisade sill
This old quarry, at the traffic circle at the ramp leading to Ross Dock, exposes the lower half of the Palisade sill (Figure 41). As noted by Walker (1969), the olivine zone of the sill produces an obvious bench along the escarpment to the immediate south, and elsewhere in the area, essentially paralleling the lower contact of the sill. In the cliff face, the olivine zone is marked by a zone of deflected columns. Flow banding is present within the olivine zone (Naslund, 1998).

STOP 3e. Concordant contact between Palisade sill and Lockatong Fm
This comprises what is probably the most spectacular exposure anywhere in the basin of the Palisade sill with the underlying sedimentary rock (Figure 42). The contact is exposed for more than 50 m along strike, and reveals the intimate structure of the Lockatong-sill contact. The sill itself is part of a series of probably once-continuous sills and plutons that extended over almost the entire Newark basin, making this component of the CAMP one of the most extensive sills in the world.
Note that the contact is extremely sharp and that there is virtually no evidence of assimilation of sediment into the sill. Here and there the sediment-sill contact jumps a few tens of centimeters up or down, but on the whole it is remarkably concordant. Because so little thickness of Lockatong Formation is exposed here, we don't know what cycle is represented by this exposure.

Ministop 3f: Discordant contact between Palisade sill and Lockatong Fm
This exposure shows the contact between the Palisade sill and Lockatong Formation jumping first up several meters and then back down (Figure 43). The more mud-rich intervals appear to behave as if brittle, with essentially no assimilation into the sill, while the tan arkose appears to have flowed at the sill contact, with considerable chaotic mixing into the sill.

STOP 3g. Outcrops of Stockton Fm along Hudson River shore
At the middle of the sharp right turn to the west. cross over rock wall onto path, and walk down to the river's edge.
From just south of here to beneath the George Washington Bridge there are scattered outcrops of variegated strata of the Stockton Formation; their facies are characteristic of the units immediately below the Lockatong in this region. Tan, gray, and purple trough cross-bedded arkose and pebbly arkose grade upwards, through a series of irregular beds, into bright purplish-red massive mudstone, at meter-scale repetitions (Figure 44).
A partial disarticulated post-cranial skeleton of a large phytosaur was recovered on private land just south of where the path comes down to the water's edge (Figure 44). It appears to have come from the transition between the arkose and red mudstone. The specimen was discovered in the summer of 1910 by Jesse E. Hyde, Daniel D. Condit, and Albert C. Boyle Jr., who were at the time graduate students of Prof. James F. Kemp of Columbia University. They contacted Barnum Brown and W. D. Mathew at the American Museum of Natural History (AMNH) in New York City, and the specimen was collected by Brown for the AMNH over a two week period in late December 1910, after a few months of negotiations with the land owners. (The phytosaur locality has been misidentified in most published reports, and is usually cited as being "a half-mile south of the George Washington Bridge, opposite 155th St. [ref. and exact quote], even though 155th St is closer to 1 mile south of the bridge! However Mathew (1910) states that the specimen is from opposite 160th St., which is approximately 1/2 mile south of the bridge; The specimen is also commonly referred to as the "Fort Lee phytosaur" (e.g. ref.), although it is actually from Edgewater. The specimen (AMNH 4991; Figure 44) consists of several posterior dorsal, sacral, and anterior caudal vertebrae, both femora, tibiae, and fibulae, a few dorsal ribs, many gastralia, and numerous osteoderms. Huene (1913) described the specimen and named it Rutiodon manhattanensis. Based on the structure of the ilium, the generic assignment is correct (Huber and Lucas, 1993; Huber et al., 1993) but the specimen is indeterminate at the species level. This is the only vertebrate reported from this facies, but it suggests that further exploration should prove fruitful. AMNH 4991 is currently on exhibit in the Hall of Vertebrate Origins at the American Museum of Natural History in New York.

Mini Stop 3h. Rotten olivine zone
Here weathering profile of the olivine zone can be clearly seen. The olivine zone is weathered to a very crumbly diabase, that according to Naslund (1998) still has much fresh-looking olivine crystals.

Undercliff Road parallels escarpment on right.
Stop 6.7 in Olsen et al. (1989) is along old trolley cut for Palisades Amusement park (Van Houten, 1969). Cut exposes upper Stockton and lower Lockatong Formation including cycles W5, W6, and Wa-c, as well as the contact with the Palisade sill including a large xenolith of cycle W5 within the sill.

Exposures in old quarry in back of buildings exposing cycles W1-6.

Driving over east portal of the tunnel
Driving over east portal of the tunnel for the former New York Susquehanna and Western Railroad. Cut below bridge comprises excellent exposures W1-6 and cycle Wa-c, (Olsen et al., 1989). Cycle W2 is very fossiliferous here with excellent articulated Turseodus and large disarticulated coelacanths (cf. Pariostegus).

STOP 4. Gorge and River Road Section
Edgewater, New Jersey
Stratigraphic Unit: Lockatong Formation
Age: Late Carnian (Early Late Triassic); 222 Ma
1. Long section of typical facies at hinge margin of Lockatong
2. Marginal to deep-water lacustrine environments
3. Well-developed Van Houten cycles in more basinward environment
4. Same cycles as at Stop 3c
5. Metamorphic mineral suite
A long section, recently expanded, is exposed along Gorge Road from its intersection with Old River Road to the contact with the Palisade sill at the Legend Hills Condominium development (Figures 45, 46). The same cycles seen at Stop 3c (from W6 upwards) are exposed here; however the section continues up into cycles not seen elsewhere along the east side of the Palisade sill, overlapping into the section exposed at Granton Quarry (Stop 5).
The most striking differences between this stop and the cycles seen at Stop 3c, are the increase in the degree of lamination in all cycles, and a decrease in the proportion of the cycles containing arkose. This is coupled with an increase in the abundance of fossils, especially fish and reptiles. The biostratonomy (sensu Schafer, 1972) of the cycles are now closely comparable to what is seen at the Yale Quarry at Weehawken, including such details as the presence of isolated bones of Hypuronector in the thin (~2 cm) massive gray mud at the base of division 2 of cycle W5. In addition the paleosol caliche in cycle W6 has disappeared and is replaced by massive mudstone.
We will begin at the north termination of Old River Road, on the south side of Gorge Road adjacent to 180 Old River Road. Cycles W5 and W6 and the underlying arkosic sequence are exposed near road level, but only W6 and the arkose are easily reached. The 5.5 m of arkose between cycles W6 and cycle Wa has some unidirectional cross-bedding indicating transport to the west and southwest (Van Houten, 1969), along with some wave-influenced sandstones, including some very handsome oscillatory ripples. (J.P. Smoot, pers. comm.). The arkose tongue and thin siltstones present in this interval are the lateral equivalents of relatively more shallow-water cycles present in the central Newark basin. Van Houten (1969) described the metamorphic minerals at this stop (Figure 45). Overall, from Stop 3c to this stop the facies trend, in terms of both lithology and fossils, is consistent with moving further away from the basin edge.
Proceed (with caution) east across Gorge Road, walk north along Gorge Road on the sidewalk, and then cross back to the exposures on the north side of the entrance road for the Legend Hills Condominiums. Lying in superposition on top of the sections exposed in 1980 are two more cycles separated by a gap of non exposure. The gap has to contain cycle W0 as seen at other nearby exposures. The two cycles are separated from the beautifully-exposed contact with the Palisade sill by a tan arkose sequence. Lithologically the two newly-exposed cycles resemble cycles W2 and W1, but are different enough that we can be sure they are indeed not simply structural repetitions of these cycles, but rather they are nearly identical to cycles G9 and G10 at Granton Quarry (Stop 5). Recognition of the identity of these two cycles at Granton Quarry is very important because it allows the sections on the east and west sides of the Palisade sill to be concatenated (Figure 28).
The arkosic sequence at the top of the section locally cuts deeply down into cycle G9; this is visible on both the south and east faces of the cut at the entrance to the Legend Hills Condominiums, and there is cross bedding visible within the the arkose. Just at the contact with the diabase, the arkose becomes very well-bedded and is capped by mudstone. This evidently marks the base of cycle G8 as seen at Granton Quarry.
Note that Gorge Road follows a fault-line ravine north of the Lockatong exposures; the eastern block is downthrown about 53 m (Van Houten, 1969).

Cut in back of Shaler Avenue School is remnant of old quarry.
Exposures consist of about 10 m of tan arkose and minor gray and purple mudstone of the upper Lockatong Formation.

Cut for west portal of the tunnel
Cut for west portal of the tunnel for the former New York Susquehanna and Western Railroad exposes tan arkose (Parker, 1993).

STOP 5. Granton Quarry,
North Bergen, New Jersey.
Stratigraphic Unit: Lockatong Formation
Age: Late Carnian (Early Late Triassic); 222 Ma
1. The classic locality for Lockatong fossils
2. All reptile and fish taxa represented
3. Well-developed Van Houten cycles
4. Granton CAMP sill
5. Bedding plane faults as evidence of inversion
Remnants of the old Granton Quarry are preserved between the new Lowes Home Building Center on the south and Tonnelle Plaza (Hartz Mountain Industries) on the north (Figure 47). Granton Quarry was actively quarried for road metal, fill and rip rap during the 1950s and 1960s and was abandoned by 1970, whereafter it was slowly consumed by commercial developments and warehouses. Nonetheless, excellent exposures remain. The site has produced, and continues to produce, extraordinarily abundant fossils, especially vertebrates, and it is certainly one of the richest sites in North America for the Triassic (Figure 39). This is also the best locality on this trip to see the details of Lockatong-type Van Houten cycles. Eleven such cycles with a thin-bedded to laminated division 2 are exposed on the sill-capped hill: seven are exposed on the south facing exposure (Figure 48), three additional cycles are exposed on the east-acing exposure; and all 11 cycles are exposed on the north-facing exposure, which is where we will examine them. The base of the section appears to be 38-46 m above the contact with the Palisade sill (Van Houten, 1969). This contact may be close to what was, prior to intrusion, the local Stockton-Lockatong formational contact. This section has been described in several papers including Van Houten (1969), Olsen (1980), Olsen et al. (1989), and Colbert and Olsen (2001).
According to Van Houten (1969), these Lockatong hornfels include calc-silicate varieties in the middle carbonate-rich part, and extensively feldspathized and recrystallized diopside-rich arkose in the upper part. Some beds of arkose show well developed cross-bedding. Because of the buff arkose at the top of nearly every cycle, these are the most visually-graphic of the detrital cycles seen on this field trip; here the many correlated changes occurring though individual cycles can be easily seen (Figure 48).
Cycles G3 and G7 (Figure 48) have produced representatives of all the known skeletal remains of Lockatong vertebrates except the holostean Semionotus. The basal portions of division 2 of both of these cycles have extremely high densities of fossil fish, especially the coelacanth Osteopleurus newarki Schaeffer (1952). Small reptiles are also surprisingly abundant, and many important fish and unique reptile skeletons have been discovered here by dedicated amateurs and donated to various museums through the years (Colbert, 1965, 1966; Colbert and Olsen, 2001; Olsen et al., 1989; Schaeffer, 1952; Schaeffer and Mangus, 1971). Without a doubt the three most spectacular skeletons of small reptiles found in the Lockatong come from the Granton Quarry. These include the type specimen of the bizarre "deep-tailed swimmer", Hypuronector limnaios (Colbert and Olsen, 2001), the peculiarly-abundant tanystropheid Tanytrachelos ahynis (Olsen, 1979), and the gliding lepidosauromorph Icarosaurus seifkeri (Colbert, 1966) (Figure 39). Larger remains occur as well, of which the most spectacular is the skull of a juvenile rutiodontine phytosaur (Figure 39), but isolated phytosaur bones and teeth are fairly common and isolated vertebrae of a metoposaur amphibian also been found.
Cycles G8 through G11 overlap with the section on the east side of the Palisade sill as exposed at Stop 4, as has been previously noted. A prediction of this correlation is that cycle W0 should be equivalent to G11. Examination of the eastern most outcrops at Granton Quarry of cycle G11 show that this is indeed the case. In fact this cycle is distinctive in having a very pyrite-rich division 2 that has strikingly bright yellow and orange clay seams on weathering, a feature not seen in other Granton Quarry cycles. With the sections from both sides of the Palisade sill combined, it is now possible to look at trends in lithology and biota at the scale of from a few thousand years (within one Van Houten cycle) to over 1 million years (i.e. three McLaughlin cycles) (Figure 28).
Although each cycle has its unique properties, there are prominent general paleontological patterns repeated in most cycles, which are well shown in cycles G7 and G3, that are common in Van Houten cycles in general (Olsen et al., 1989). The most obvious and least surprising pattern is seen in the correlation between the degree of fish preservation and the degree of lamination of the sediments. Microlaminated beds tend to preserve beautifully articulated fish, laminated mudstones produce disarticulated but still associated fish, and mudcracked mudstones have only dissociated scales and skull bones. This correlation almost certainly reflects the often-quoted dependence of fish preservation on a lack of oxygen, bioturbation, macro-scavenging, and physical disturbance.
Inversely correlated with this fish-preservation trend is one which at first appears very peculiar: a trend to lower fish diversity in the beds with the best fish preservation, and vice versa. This observation is based on the results from the Yale Quarry in Weehawken (Olsen et al., 1989) (Figure 37). This trend is all the more surprising because many more fish (individuals) are identifiable from the beds producing the best-preserved fish. The explanation seems to be that the highest diversity of lake environments tends to be near the shores, whereas the deeper-water zones tend toward low diversity (this is especially true for lakes with anoxic bottom waters, because they lack benthic forms). Thus, the cycle in fish diversity is a consequence of proximity to the shore which varies as a function of depth, which in turn controls the degree of lamination and absence of bioturbation.
The taphonomic pattern seen in the microlaminated division 2 of Van Houten cycles fits a chemically-stratified lake model (Bradley, 1929, 1963; Ludlam, 1969), in which bioturbation is perennially absent from the deeper parts of the lake bottom because the bottom waters lack oxygen, which is required by almost all macroscopic benthic organisms. Chemical stratification (meromixis) can arise by a number of mechanisms, but the main physical principle involved is the exclusion of turbulence from the lower reaches of a water column. This tremendously decreases the rate at which oxygen diffuses down from the surface waters, and retards the upward movement of other substances. The main source of water turbulence is wind-driven wave mixing. This turbulence usually extends down about one-half the wavelength of surface wind waves, which depends on the fetch of the lake, wind speed, and wind duration. If the lake is deeper than the depth of the turbulent zone, the lake becomes stratified with a lower non-turbulent zone and an upper, turbulently-mixed zone. The thickness of the upper mixed zone is also dependent on density differences between the upper waters (epilimnion) and lower waters (hypolimnion), which can be set up by salinity differences (saline meromixis) or by temperature differences, as seen in many temperate lakes. In the absence of saline or temperature stratification, chemical stratification can still arise in a deep lake with relatively high levels of organic productivity. Because oxygen is supplied slowly by diffusion, consumption by bacteria of abundant organic matter sinking into the hypolimnion plus oxidation of bacterial by-products eliminates oxygen from the hypolimnion. Lakes Tanganyika and Malawi in East Africa are excellent examples of very deep lakes in which there is very little temperature or density difference between the epilimnion and hypolimnion, but still chemical stratification occurs with the exclusion of oxygen below 200 m. Such a pattern is common in deep tropical lakes. The preservation of microlaminae and fossils in Van Houten cycles may have been a function of great water depth relative to a small surface area of the lake, which in the case of Lockatong lakes was none the less huge (in excess of 10,000 km2); the depth, based on the area of the lake that must have been below the turbulent zone, was a minimum of 80 m during the deposition of the microlaminated beds (Olsen, 1990).
Thus, Van Houten cycles with a microlaminated division 2, such as G3 and G7 at Granton Quarry, and W5 and W6 at Stop 4, reflect the alternation of shallow, ephemeral lakes or subaerial flats with deep perennial lakes with an anoxic hypolimnion set up by turbulent stratification under conditions of relatively high primary productivity and low organic consumption (e.g. low ecosystem efficiency). The low organic content of divisions 1 and 3 of Van Houten cycles in general probably reflects higher ecosystem efficiency caused by shallow water depths, rather than lower total organic productivity.
This model also accounts for an exceptionally useful (for collecting) property of those cycles with a microlaminated division 2. Articulated small reptiles, such as Tanytrachelos, are found with predictable regularity in the basal few millimeters of the microlaminated unit. This pattern was first noticed in 1977 in Van Houten cycles in the upper member of the Cow Branch Formation of the Dan River basin (North Carolina and Virginia) (Olsen et al., 1978). The discovery of Tanytrachelos in the base of microlaminated units in this southern basin prompted a concerted search for reptiles in the homologous position in Van Houten cycles 500 km further north, in northeastern New Jersey. It took less than an hour for PEO to find the first skeleton, and that was at the locality described by Gratacap (1886) in Weehawken. Although Gratacap collected several hundred fish specimens from this site, no reptiles were found. That is, because without an appropriate model of why extra effort should be expended in those specific units, they get short shrift from the collector due to the presence of abundant fish in other parts of the unit. After the discovery of Tanytrachelos at Gratacap's locality, PEO informed Steven Steltz and James Leonard (two dedicated amateur collectors) about their predictable pattern of occurrence. The next time they visited Granton Quarry they found a complete Tanytrachelos (Figure 39) as well as pieces of other Tanytrachelos individuals, exactly where predicted. Prior to this, articulated Tanytrachelos had not been found at Granton Quarry despite the fact the site had been a famous fossil locality for several decades.
With the sections on the east and west sides of the Palisade sill now combined, several larger-scale patterns emerge that are reinforced by data from elsewhere in the Newark basin. Looking at the distribution of fossil fish taxa through several cycles of different scales, a hierarchy of self-similar ecological patterns from the scale of the Van Houten cycle to the long modulating cycle is revealed. The full basic pattern of occurrence is, from oldest to youngest, Semionotus; Semionotus + Osteopleurus; Osteopleurus + redfieldiids (especially Synorichthyes); Osteopleurus + redfieldiids + Turseodus; Turseodus + redfieldiids, and finally just Turseodus. Most of this sequence can be seen in cycles W6 and W5 (Figure 37) at the Yale quarry in Weehawken, supplemented by data from the Eureka Quarry (Eureka, Pennsylvania). The pattern can also be seen within the short modulating cycle, e.g. N2 (which contains cycles W6 - W3). Thus, Semionotus is dominant in cycle W6, and Osteopleurus and Turseodus are dominant in cycles W5-W3. The basic pattern can be seen again in the McLaughlin cycle, such as the Nursery Member. Semionotus is abundant in short modulating cycle N2, near the bottom of the member, and Osteopleurus and Turseodus are dominant in short modulating cycles N3-N4. Finally, sequences of McLaughlin cycles, making up long modulating cycles, also show the pattern, with Semionotus being more common in the Princeton Member than in the Nursery Member, while Semionotus is virtually absent from the Ewing Creek Member. The distribution of fish taxa largely tracks the lithology of the fish-bearing units. More clastic units tend to be dominated by Semionotus, while more calcareous (or formerly calcareous) units tend to be dominated by Turseodus. In turn, the lithology is a function of paleoclimate, with more calcareous units being deposited higher in the cycles by more concentrated lake waters in drier times.
Interestingly, a very similar pattern is evident in Jurassic age strata of the Hartford basin (the Shuttle Meadow and East Berlin formations), Deerfield basin (the Turners Falls Formation, temporally equivalent to the East Berlin Formation), and probably also in the less well known Newark basin (Feltville, Towaco and Boonton formations). In these Jurassic age strata, Osteopleurus and Turseodus are absent, with Redfieldius being the only redfieldiid present. Again, Semionotus tends to occur low in the Van Houten, short modulating, and McLaughlin cycles.
The stratigraphic sequence in the Hackensack Meadowlands, underlying the Granton sill to the west of it's dip slope, consists of arkosic tan sandstones, overlain by black shales (that surely represent much of the remainder of the Lockatong Formation), which are in turn overlain by red mudstones of the Passaic Formation (Parker, 1993). If something like the average accumulation rate, based on the thickness of the Princeton, Nursery, and Ewing Creek members in the vicinity of North Bergen and Edgewater (i.e. 18 m/McLaughlin cycle), was maintained upward to the position of the Graters Member of the Passaic Formation (encountered in a boring; Lovegreen, 1974 cited in Parker, 1993), there is sufficient stratigraphic thickness in this area for the rest of the Lockatong and basal Passaic Formation.
At the south-facing exposures cycles G1 and G2 are injected by diabase of the 20 m thick Granton sill (Van Houten, 1969), another component of the CAMP, which has protected the Lockatong Formation from erosion in this area. Notice the absence of prominent folding at the diabase-sediment contact. Because this sill is thin, and the Palisade sill fairly remote, much of the sedimentary rock is not as metamorphosed as at previous stops; some cycles still have considerable organic matter.
One or two bedding plane thrust faults, always thrusting to the east, are present in division 2 of nearly every cycle at Granton Quarry. Slickensides are usually present and indicate that movement occurred parallel to dip. All the joint sets are cut by these thrusts, their displacement indicating that each fault has a net slip of 0.5 to 1.5 cm. This type of minor thrust fault is evident in virtually all Newark Supergroup lacustrine cycles and can be seen at every stop of this trip. The fact that all of these faults are thrusts requires post-depositional northwest-southeast shortening, a steepening of dip, and a σ3 that would have been vertical. This is completely incompatible with the extension that produced the basins; thus we take these faults as evidence for structural inversion.

Dip slope of Palisade sill
Dip slope of Palisade sill mantled by northwesterly dipping Lockatong Formation. Contact appears concordant from here to Granton Quarry.

Contact of uppermost Stockton with Palisade Sill directly on left (east).
Stockton dips 15° NW and the contact dips 45° to 80° NW. Recrystallized arkose of Stockton Formation is sheared and dragged upwards close to contact with slickensides indicating down-dropping to the west. There are no indications of movement in the diabase, however. Basal Lockatong hornfels 100 m to the north, dip 15° NW and lie concordantly on the Palisade Sill. A possible interpretation of these exposures might be that the apparent movement in the Stockton occurred during intrusion of the sill.

West portal of tunnel for Penn Central Railroad.
On left is open cut in Stockton Formation and west portal of tunnel for Penn Central Railroad. Cut exposes upper Stockton beds described by Darton (1883) and Olsen (1980b). At east end of cut at tunnel is excellent exposure of the contact between the Stockton Formation and the Palisade Diabase. Stockton beds dip at 15° NW while the irregular contact dips at 60° NW. This contact is locally welded according to Darton (1890) and Lewis (1908). This appears to be a continuation of the contact surface exposed at the Penn Central tunnel described above and this is another exposure where the Palisade sill is described as having a dike-like appearance. Actually, these exposures and similar ones near by are perhaps better explained by a local stepping up of the Palisade sill as described by Olsen (1980b).

Ridge underlain by more resistant strata in proximity to the Graters Member.
Ridge underlain by more resistant strata in proximity to the Graters Member. Outcrops of this member occur further south at abandoned diabase quarry at Laurel Hill.

Crossing over Hackensack River.
At one stage or another the Hudson probably flowed along this route (Lovegreen, 1974).

STOP 6. Bluff and Copper Prospect at Lyndhurst, New Jersey
Stratigraphic Unit: Passaic Formation
Age: Late Norian (middle Late Triassic); 212 Ma
1. Part of ridge representing wet phase of long modulating cycle P4
2. Wetter facies better cemented
3. Kilmer Member of Passaic, marginal lacustrine facies
4. Vague pattern of Lockatong cycles
5. Accumulation rate similar to cored areas
6. Copper hosted in sandstones
7. Drier facies similar to more basinward facies with gypsum nodules
8. Footprints abundant in lake margin facies
9. Dinosaurs becoming larger and more abundant
10. Crurotarsans still very abundant
The Meadowlands are bordered on the west by a distinct ridge that extends from Hackensack to Kearny (NJ). For the most part this ridge is characterized by a heterogeneous assemblage of red mudstones and sandstones. However, there are a few purple and gray units present; based on their stratigraphic position they are part of long modulating cycle P4. The most eastern gray and purple unit probably is the lower part of the Kilmer Member (Figure 14).
Stop 6 is located on the eastern side of this ridge (Figure 49) and exposes the uppermost part of member T-U and the lower half of the Kilmer Member (Figure 50). In the central Newark basin, the basal Kilmer Member includes a prominent Van Houten cycle with a well-developed black division 2. In the region around New Brunswick (NJ), this black shale and the underlying division 1 of this cycle are often rich in copper minerals, so much so that during mapping of this member its surface trace became known as the “dead zone” because plants have trouble growing on the copper-rich regolith. There is surface evidence of copper prospect pits where and unnamed brook crosses the Kilmer Member in Piscataway (NJ), but these are not mentioned by either Lewis (1907) or Woodward (1944).
In the outcrops in the northeastern Newark basin, the same Van Houten cycle apparently lacks black shale, instead having a purple shale with associated tan or white sandstones. The unit is still copper-mineralized, at least locally, and where intruded by thin diabase sills 2 km to the south-southeast in North Arlington (NJ), it was commercially exploited in what is supposed to be the oldest copper mine in North America – the Schuyler mine (Lewis, 1907). According to Woodward (1944), the Schuyler copper was discovered a few years prior to 1719 and an extensive mine was developed there, remaining profitable on and off until nearly 1830. In addition to copper it also produced a small amount of silver and trace amounts of gold. Possibly the first steam engine to arrive in North America (1753) was used to drain the mine, but the machine was damaged by fire in 1765, 1768, and 1773 (Woodward, 1944). There were several attempts at reopening the mine through the latter part of the 19th and earliest 20th centuries, but by 1903 the mine had been abandoned because of various engineering problems, and no doubt the much greater profitability of the copper deposits in the central and western United States.
The exposures at this stop may be the prospect mentioned by Woodward (1944) on the Kingsland estate, inspired by the Schuyler mine, but never worked extensively. An exploratory shaft at least was opened, and the now-cemented entrance is still visible. Tan and white sandstones associated with purple and gray mudstone are exposed, and mineralized with the same minerals as at the Schuyler mine, including chalcocite (black copper sulfide), chrysocolla (bluish-green copper silicate), malachite (green copper carbonate), and azurite (blue copper carbonate) (Figure 50).
The overall section at this stop consists of lower red massive mudstones of member T-U, followed by the tan and white sandstones surrounding a purple well-bedded mudstone of the basal part of the Kilmer Member. This is succeeded by massive red mudstones, a well bedded interval, and then red mudstones and fine sandstones with gypsum nodules. The overall stratigraphy is very similar to the expression of member TU and the Kilmer member in the NBCP cores.
A large collection of very well-preserved reptile footprints was made near here by Lawrence Blackbeer in the late 1960s (pers. comm., 1985; Olsen and Baird, 1986). Although the exact location was not recorded, the lithology of the footprint slabs is consistent with the local expression of the Kilmer Member. The assemblage is distinguished in the Newark basin by the presence of relatively large grallatorid footprints, up to the size of Anchisauripus tuberosus; this is the oldest level in the basin with such tracks (Figure 51). The nomenclatural problems associated with these kinds of footprints are discussed in the text for Stop 7. Relatively large examples of the ornithischian dinosaur track, Atreipus milfordensis, are present, along with a new dinosaurian ichnogenus ("Coelurosaurichnus" sp. of Olsen and Flynn, 1989), as well as the non-dinosaurian Brachychirotherium parvum, and Rhynchosauroides sp.
Rhynchosauroides brunswickii and Grallator sp. were found specifically at this site by PEO during the early 1970s. PEO also found Kouphichnium sp., made by horseshoe crabs, as well as Scoyenia burrows. These trace fossils were all found in the red siltstones immediately above the gray sandstones.
Further southwest, (0.3) mi are additional exposures along former Erie Lackawanna Railroad tracks showing an unusual reverse fault dipping to the west and downthrown on the east. Slickensides confirm the dipslip nature of the fault.
About 2.9 km west of here on the west bank of the Passaic River are what were the Avondale and Belleville quarries that produced a large amount of building stone ("brownstone") to the region (based on location of quarries shown by Darton et al (1908). These quarries are now the location of Father Glotzbach and Monsignor Owens parks in Nutley (Avondale) New Jersey. These quarries produced a fragmentary phytosaur skull (Edwards, 1895; Lull, 1953; Baird, 1986b) as well as dinosaur footprints (Woodworth, 1895) and fragmentary plant remains (Nason, 1889). Unfortunately the whereabouts of the dinosaur tracks are unknown. The stratigraphic level of the quarries appears to be close to the Cedar Grove Member and almost certainly with in long modulating cycle P6.

Crossing Passaic River.

Underpass for North 6th Street.
Outcrop on right is a gray sandstone of the Cedar Grove Member. According to Neal K. Resch (quoted in Cornet (1977) The gray zone is roughly 4.8 m thick, the basal beds of which consists of 90 cm of black laminated shale passing upward into gray shale. This is followed by 60 cm of tan sandstone and 3 m of thinly bedded gray sandy shale and sandstone, grading upward into red sandstone. During the construction of Route 280, Resch collected conchostracans and leafy shoots of Brachyphyllum from the shale and various reptile footprints, including Apatopus sp.. Brachychirotherium sp., Grallator sp., and Anchisauripus sp. from the well bedded siltstone. Cornet (1977) described a palynoflorule from gray shale (sample SPPS-23A) indicating a probable early Rhaetian age. This unit was originally thought to be part of the Ukrainian Member, but Witte et al. (1991) show that the red beds directly overlying this gray sequence are of reversed polarity indicating correlation with the Cedar Grove Member.

Exposures of Passaic Formation
Exposures of Passaic Formation in cuts for connections to the Garden State Parkway.

Partial trackway
Exposures on left have produced a partial trackway of Apatopus sp., a phytosaurian trackway figured in Baird (1986b). This is amongst the youngest Apatopus know dating from about 500 ky before the Triassic-Jurassic boundary.

Huge cut in Orange Mountain Basalt
Type section of the formation (Olsen 1980a) (modified from Olsen and Schlische in Olsen et al. (1989).
When this road was constructed in 1969, this 33 m high roadcut was the deepest federally financed highway cut east of the Mississippi River (Manspeizer, 1980). A complete section of the lower flow unit of the Orange Mountain Basalt is exposed (Figure 52) (Olsen, 1980a,c; Manspeizer, 1980; Olsen et al., 1989). Unusual curved patterns of columnar joints are present in the cut, described as chevrons, oblique and reverse fans, and rosettes. This flow overlies red beds of the Passaic Formation which contains the Triassic-Jurassic boundary 10 m or so below the basalt contact. During the construction of this cut in 1969, PEO found several examples of Batrachopus sp. just beneath the contact with the Orange Mountain basalt.
At this outcrop of the type section, the west-dipping lower flow of the Orange Mountain Basalt is almost completely exposed (Olsen, 1980a; Puffer, 1987). The Orange Mountain Basalt is an HTQ basalt (Puffer and Lechler, 1980) which at this exposure shows a complete, beautifully displayed Tomkeieff (1940) sequence (Olsen, 1980a; Puffer, 1987) almost exactly comparable to Long and Woods (1986); Type III flows. The thin (6 m) lower colonnade is fine-grained with large columns, the entablature is thick (35 m) with very well-developed curvicolumnar jointing, and the upper colonnade (10 m) is massive with poorly-developed columns.
According to Lyle (2000) the curvicolumnar jointing of the type seen at this outcrop are a direct result of ponded water on top of the cooling flows. The curved columns result from joints forming normal to large widely-spaced vertical master fractures in a hexagonal array that form very early in the cooling of the basalt flow. Water percolates down the mater fractures and provides a surface cooling faster than adjacent basalt resulting in surface-normal hexagonal fractures that propagate away from the master fractures and curving towards the upper cooling colonnade of the flow. The master fractures can be clearly seen separating bowl-shaped fans of the curvicolumnar jointing. Additional bowl-shaped fractures, as seen here may also have helped to control the radiating pattern of columns.
The largest fault in this exposure strikes N05°E, dips 80°E, and does not visibly offset subhorizontal cooling joints, suggesting that it is a predominantly strike-slip fault (Schlische, 1985). Another fault with a 25-cm wide breccia and gouge zone strikes N30°E and dips 70°NW. Although slickensides suggest that the last slip on the fault was predominantly dip-slip, this fault may have originated as a normal fault during NW-SE extension. Several minor slickensided surfaces, mostly reactivated cooling joints in the basalt, show evidence of an earlier period of predominantly normal-slip and a later period of predominantly strike-slip (Schlische, 1985)
The Orange Mountain Basalt was probably fed by the Palisade sill (Ratcliffe, 1988) and it (and correlative units in other basins) represents the oldest of the known CAMP lava flows, flowing out less than 20 ky after the Triassic-Jurassic boundary (Olsen et al., 1996b).

Exposures of ?second flow of Orange Mountain Basalt.

Unexposed contact between Feltville Fm - Orange Mtn
Unexposed contact between Feltville Formation and underlying Orange Mountain Basalt below this point.

Contact between Preakness Basalt and Feltville Fm
Contact between Preakness Basalt and Feltville Formation poorly exposed on south side of road and type section of the Preakness Basalt in deep open cut for Route 280 (modified from Olsen and Schlische in Olsen et al. (1989).
This type section (Olsen, 1980a.c) exposes about 100 m of the lowest flow of the Preakness Basalt, the thickest extrusive multiple flow unit in the Newark basin section (Figure 53). It is a high-Ti, high-Fe quartz-normative tholeiite indistinguishable from the Holyoke Basalt of the Hartford basin. The lowest flow is characterized by a thin lower colonnade; a massive, thick, and coarse-grained entablature with very characteristic splintery columns; a massive upper colonnade; and a comparatively thin vesicular flow top. It does not closely resemble any of the flow types of Long and Wood (1986), but it is similar to the second flow of the Sander Basalt of the Culpepper basin, the Holyoke Basalt of the Hartford basin, and some parts of the North Mountain Basalt of the Fundy basin.
The splintery columns are defined by what Faust (1977) calls a platy prismatic joint system, and it is characteristic of the lower flow throughout the areal extent of the Preakness Basalt. The joint system is not hexagonal and does not appear to be a faulting phenomena (although faulting does exaggerate it). Its origin remains a mystery.
Several faults cut the rocks at this exposure (Schlische, 1985) but most are now covered with gunnite for the safety of traffic. The largest fault zone strikes 005°, dips 85°E and is marked by a gully 1.5 m wide. The zone of brecciation varies in width from 40 to 60 cm. Slickenlines are curved from more steeply-plunging to more shallow-plunging attitudes. Another major fault strikes 035° and dips 83°NE and is marked by a breccia zone (with clasts 2 to 5 cm in size) 35 to 40 cm wide. Slickenlines rake 35°N. Three other macroscopic faults have orientations 010°, 82°NE; 040°W, 82°NE; and 020°, 83°NE; brecciated zones are 10 to 15 cm wide. A systematic study of minor fault populations showed that, although most of the faults followed preexisting joints within the basalt, the slickenside striae strongly indicated strike-slip on NW-striking planes (Schlische, 1985), consistent with the larger faults at this exposure.
At this locality the contact (now overgrown) with the underlying Feltville Formation is simple, with massive basalt of the lower colonnade in direct contact with sedimentary rocks. At other localities thin flow units, pillow lavas or rubble flows are present (Olsen, 1980a).

Entering former course of Hudson River
Take exit 4A onto Eisenhower Parkway south paralleling to the south the ancient course of the Hudson. Entering former course of Hudson River (Johnson, 1931).

Two flows of the Hook Mtn Basalt and underlying upper Towaco Fm
Outcrop on left is of the two flows of the Hook Mountain Basalt and underlying upper Towaco Formation described in Olsen et al. (1989, Stop 6.3).

STOP 7. Walter Kidde Dinosaur Park, Riker Hill, Roseland (NJ)
Tectonostratigraphic Sequence: TS IV
Stratigraphic Unit: Towaco Formation and Hook Mountain Basalt
Age: middle Hettangian (Early Jurassic); ~202 Ma
1. Long section of upper Towaco Formation: type section
2. Very thick Van Houten cycles
3. Peak wet phase of long modulating cycle H1 and Laskar cycle LaCV1.
4. But dry phase of 404 ky cycle
5. Footprints very common in lake margin sheet deltas
6. Typical earliest Jurassic assemblage
8. Extraordinary preservation
7. Includes level of Dinosaur State Park in Hartford basin
8. Level of unique assemblage of track types, including synapsids
9. Association with waning phases of the CAMP
The discovery of dinosaur footprints in the "Riker Hill" (aka "Roseland") quarry - part of which is now the Walter Kidde Dinosaur Park (Figure 54), was first reported in the local newspapers of Livingston and Roseland, NJ about 1968 (Figure 55). The quarry occupied a 55-acre tract on the northeast side of Riker Hill in Roseland, and was owned by the Walter Kidde Company, Inc. Over the next few years the Riker Hill quarry became locally very well known for its abundant reptile footprints, and in 1971 the owners agreed to give the most fossil-rich portion of the tract to the Essex County Department of Parks and Recreation. The resulting publicity made the site internationally famous. In 1977 the 17 acres of the present Walter Kidde Dinosaur Park was formally donated to Essex County (Figure 54) and today the park remains one of the premier sites for Jurassic age fossils in eastern North America. In this paper the 55-acre tract will be referred to as the Riker Hill quarry, and the term Walter Kidde Dinosaur Park will be used for the 17-acre portion of the Riker Hill quarry that is now the county park. This stop has been described in part by Olsen (1980b) and Olsen et al. (1989), and described in detail by Olsen (1995).
Although thousands of footprints have been found in the Riker Hill quarry, only a tiny fraction have made it into museum collections. Presently, the Walter Kidde Dinosaur Park is administered by the Center for Environmental Studies of the Essex County Department of Parks, Recreation and Cultural Affairs. Prospecting and collecting are no longer allowed at the Dinosaur Park without permission from the Center for Environmental Studies.
The Towaco Formation at the Riker Hill quarry (the type section; Olsen. 1980a, c) consists of relatively fine-grained red, gray, and black units, mostly mudstone and fine sandstone. This facies represents some of the more basinward deposits of the Newark basin Jurassic, although the sequences deposited near the geographic center of the basin have been lost to erosion. The Hook Mountain Basalt as seen in the park is representative of most of its preserved extent.
Prior to the development of the Nob Hill complex on what was the east side of the Riker Hill quarry, the exposed section below the Hook Mountain Basalt consisted of the uppermost red beds of one Van Houten cycle (RVH-1), two complete gray and black shale-bearing Van Houten cycles (RVH-2 and RVH-3), and the lower part of an entirely red fourth cycle (RVH-4) (Figure 56). Together, these cycles constitute most of a short modulating cycle (~100 ky duration). Presently, only the uppermost beds of RVH-3 and RVH-4 are exposed, representing less than ~40 ky of Jurassic sedimentation in the drying phase of a 100 ky short modulating cycle, which is in turn the drying phase of a 404 ky McLaughlin cycle, itself in the wet phase of a 1.75 my long modulating cycle (Figure 4). In the following description of the paleontology, all of the fossils will be keyed into the section shown in Figure 56 so their positions within the pattern of cyclically-shifting climate can be seen.
Varied assemblages of plant and animal remains have been found in the Riker Hill quarry. Most famous are the reptile - notably dinosaur - footprints, but well-preserved plants, fish and even insect body fossils have been found as well. As in the Towaco Formation in general, trace fossils (mostly tracks and burrows) are abundant in the red and gray beds of divisions 1 and 3 of the Van Houten cycles, while insects, fish, plants, and pollen and spores are restricted to the gray and black beds of division 2. Apart from a single tooth fragment and a coprolite, all of the fossils of tetrapods from the Walter Kidde Dinosaur Park are trace fossils.
Pollen assemblages recovered from units 9-10 are, as is typical for the Early Jurassic of tropical Pangea, dominated by the extinct conifer genus Corollina (Classopolis), accompanied by various other conifer, cycadophyte, and fern spores (Figure 57) (Cornet, 1977). Remains of cheirolepidiaceous conifers are the most common macroscopic plant fossils in all facies at Riker Hill. Compressed wood and fossil charcoal almost certainly belonging to these plants are found in all of the gray and black beds at the, and large roots are present in the gray siltstones and sandstones of unit 16 of division 1 of cycle RVH-3. Leaf and shoot compressions and cone fragments are similarly present in all the gray beds, and well preserved material occurs in units 9 and 10 of division 2 of cycle RVH-3, which is still exposed. Impressions of leafy shoots and clay casts of roots and stems are common in the red units, sometimes on the same surfaces as footprints (Figure 57). Imponoglyphus torquendus was originally described from Late Triassic age strata of the former Soviet Union and an example of this form taxon has been described from Walter Kidde Dinosaur Park by Metz (1984). This form species consists of impressions resembling truncated cones fitted into one another. Imponoglyphus torquendus is almost certainly an impression of a conifer shoot similar to that shown in Figure 57. From the extreme dominance of the remains of cheirolepidiaceous conifers in all facies at the, both as macro- and microfossils, it is clear that the woodlands and scrub lands of the Newark basin in Towaco time were strongly dominated in biomass by the cheirolepidiaceous conifers. However, it is not yet possible to tell how many biological species of cheirolepidiaceous conifers are represented, and the species diversity could be quite low.
A rich invertebrate trace fossil assemblage has been recovered over the years from the Riker Hill quarry, mostly from strata exposed in Walter Kidde Dinosaur Park (Figure 58). As described by Metz (1992), Cochlichnus anguineus consists of smooth, narrow (1.5-2 mm), sinusoidal, unlined, and unbranching horizontal burrows possibly made by nematodes or perhaps fly larvae. Helminthopsis sp. (Metz, 1991) is a smooth, straight to gently winding burrow of constant width that does not show sediment layer crossings. It may possibly have been produced by a worm-like form. Metz (1992) has described two species of Planolites, a form genus comprised of small, horizontal or inclined filled burrows lacking exterior ornament or interior structure. Planolites montanus is a very small form (1-1.5 mm) having occasionally-branching burrows, often curved, filled with material coarser than the matrix, and with crossovers and interpenetrations (Metz, 1991). Planolites beverleyensis is a larger (5-6 mm) burrow that is similar in form and filling to P. montanus, but shows discontinuous rings where the burrow tapers (Metz, 1991). A perhaps similar form is shown in Figure 58; in this example a burrow which shows distinct annuli is present, which apparently was broken up at one end, releasing pellets which were scattered by a weak current. In general, however, Planolites is a catch-all taxon with few defining characters, that could have been made by variety of worms or even arthropods. Trepyichnus bifircus, as described by Metz (1991), consists of a "... straight to curved trace (1 mm in diameter), with short extensions (1 mm - 2 mm) possessing slightly thickened terminations projecting from junctures between longer segments, creating a zigzag pattern". The originator of this kind of trace is unknown. Biformites sp. and Fustiglyphus roselandensis are possibly related to Trepyichnus described by Boyer (1979) from the Riker Hill quarry. Fustiglyphus consists of two kinds of linked trails: a thin (0.4-0.6 mm) part 4-7 mm long with distinct annulae and a thicker (2-2.5 mm) part 2 to 3 mm long with faint annulae. There is a faint groove running down the middle of the trace. Biformites is a tapering trace with annulae and a faint longitudinal groove. According to Boyer (1979), the Roseland Fustiglyphus is a succession of repeated Biformites-like traces, probably produced by a small arthropod seeking refuge in a deteriorating environment. Metz (1992) has described Scoyenia gracilis from Walter Kidde Dinosaur Park, where it is not common. Scoyenia is a lined burrow with a meniscate filling and distinct rice-grain-like prod marks on the outside surface. This form genus is the most common trace fossil in deposits of Triassic age in the Newark basin (and Newark Supergroup). It is markedly more rare in the Newark basin Jurassic, notably so in the Towaco Formation. There is little consensus on the makers of Scoyenia with opinions ranging from polychaete worms (D'Alessandro et al., 1987), to insects (Frey and others, 1984), and crayfish (Olsen, 1988). This taxon is very badly in need of detailed study.
Insect body fossils are represented by a single beetle elytron (wing cove) from unit 10. The narrow rows of punctures between ridges and the general shape of the elytron distinguishes the beetle family Cupedidae, hence the common name "reticulated" beetles. The elytron from Walter Kidde Dinosaur Park most closely resembles the Early Jurassic genus Liassocupes Whalley 1985 (Figure 58, Huber et al., 2002). The cupedids are often regarded as the most primitive of the beetle families. The family is extant; both the larvae and adults feed on rotting wood. Cupes concolor is the most common living member of the family in the United States and is very similar to the Walter Kidde Dinosaur Park fossil. This isolated elytron is illustrative of how incomplete our sampling of Early Jurassic life is. Then as now, beetles were probably the most diverse insect group, and insects the most diverse animal group. The lack of insect fossils is probably due to both a real bias against fossilization as well as a collection bias. Recent years have seen a strong increase in the number of insect body fossil occurrences in the Newark Supergroup (Fraser et al., 1996; Huber et al., 2002; Olsen, 1988) and there is no reason not to expect more finds at Walter Kidde Dinosaur Park (especially with intense collecting of unit 10).
Several trackways attributable to Acanthichnus (Hitchcock, 1858) have been found at Walter Kidde Dinosaur Park (Figure 59). This ichnogenus is distinguished by two rows of thin impressions. These kinds of tracks could be made by any of a number of types of walking insects. The well-defined trackways shown in Figure 59 come from the lower part of unit 5, which has very small oscillatory ripples characteristic of very shallow water.
The only fish genus found thus far at the Walter Kidde Dinosaur Park is the holostean Semionotus, the most abundant fish throughout the Newark Supergroup Jurassic. Semionotus has been found in four units in the Riker Hill section (Fig. 4). Cycle RVH-3 has produced articulated fish in the upper microlaminated zone (unit 23c) and the overlying platy fine sandstone (unit 23b) of division 2. Fish fragments have been found in cycle RVH-2 in the gray claystone that produced the beetle elytron (unit 10) in division 2, and in a coprolite in the lower part of division 3 (lower part of unit 5).
In the entire Newark basin, the Towaco Formation has produced only Semionotus. It is very unusual for lakes, especially large ones, to have only one genus, and other genera are probably present but in low abundance. Studies of thousands of well-preserved Semionotus from the Towaco Formation of Pompton (NJ) by McCune (1987, 1996) show that although the genus-level diversity is very low, the species-level diversity may be very high. McCune has identified over 30 species of Semionotus in the laminated division 2 of a single Van Houten cycle. This type of high species diversity in one genus in a geographically circumscribed area is termed a "species flock". Closely analogous species flocks of cichlid fishes occur today in the great lakes of Africa, and species flocks of the fruit fly Drosophila occur in Hawaii. In these modern cases, the high species diversity correlates with a local deficit in the generic diversity due to geographic isolation.
At the Riker Hill quarry, at least three species of Semionotus appear to be present, although the preservation is too incomplete for certain identification (Figure 58). These are Semionotus tenuiceps, a small thin bodied form with small dorsal ridge scales, and a large form. Semionotus tenuiceps has a distinct hump at the back of the head and has expanded shield-like dorsal ridge scales. The two other forms are much too poorly preserved to be assigned to known species.
Preservation of the Semionotus at the park is variable (Figure 58). Fish from unit 24 in division 2 of cycle RVH-2 are preserved as flat films. No bone appears to be preserved, although an organic matrix outlines the gut and eye regions. The mineral matter of bone is a form of calcium phosphate (hydroxyapatite). Generally, in the process of fossilization, the cellular spaces within the bone become filled with minerals - often calcite - introduced by groundwater; the original mineral matter of the bone becomes somewhat altered to carbonate fluorapatite (i.e. francolite) (Shemesh, 1990). In anoxic environments, degradation products of the organic matrix of the bone also remain, coloring the bone black. In the case of the Semionotus in unit 23c, the phosphatic mineral matter of the bone has been dissolved away, leaving an outline marked by the residuum of the organic matrix of the bone and organic matter in the gut. This dephosphatization has been noted elsewhere in the Newark Supergroup and is generally more prevalent in the portions of lacustrine strata farther from the basin edge (McDonald and LeTourneau, 1989). A completely different style of preservation is represented by the fish from unit 23b, in which siltstone and fine sandstone have preserved the fish as a natural mold in high relief (Figure 58). In this case the bone tissue has been dissolved by recent near-surface weathering. Bone is preserved (along with the decay products of the organic matrix) in the Semionotus fragments from unit 10 in division 2 of cycle RVH-3. Bone is also preserved in the fish fragments in a coprolite from the lower part of unit 5 (in the lower part of division 3 of cycle RVH-3); however, the organic matrix is not preserved in the red mudstones, and hence the bone is white. The coprolite itself may be the excrement of a small theropod dinosaur.
By far the most spectacular fossils found at the Riker Hill quarry are tetrapod footprints. Thus far, excellent examples of Ameghinichnus, Batrachopus, Grallator, Anchisauripus, Eubrontes, and Anomoepus have been found. Only one other ichnogenus is known from elsewhere in the Newark basin Jurassic - the lepidosauromorph track Rhynchosauroides.
Ameghinichnus was first found by Larry Felder in 1978, in the upper beds of unit 5 of Walter Kidde Dinosaur Park. The ichnogenus was established by Casamiquela in 1964 for small five-toed quadrupedal tracks from the Late Jurassic Matilde Formation of northern Santa Cruz province in Argentina. The Towaco form differs somewhat from A. patagonicus (Casamiquela, 1964) and we consider it to be a new (although unnamed) species. The genus is characterized by a pentadactyl manus and pes of equal size, with nearly symmetrically-disposed digits of subequal length (Figure 59). Although the inferred structure of the manus and pes are consistent with mammals in both the type and new species, this arrangement appears phylogenetically well below the base of the Mammalia. In fact, such tracks could have been made by any of a variety of advanced therapsids, including the tritylodonts (which were contemporaneous with both Ameghinichnus ichnospecies) or trithelodonts (which were contemporaries of at least the Towaco ichnospecies). The size of the Towaco form is more consistent with trithelodonts or the largest of the Early Mesozoic mammals. Trithelodonts (e.g. Pachygenelus monus) have been found in abundance in the earliest Jurassic McCoy Brook Formation of the Fundy basin in Nova Scotia, in strata very close in age to the Towaco Formation (Olsen et al., 1987; Shubin et al., 1991). We therefore favor trithelodonts as the makers of the Riker Hill species of Ameghinichnus, although we cannot exclude other therapsids (including mammals) on the basis of existing evidence. Since the discovery by Mr. Felder, several more specimens of Ameghinichnus have been recovered from closely adjacent beds, although all of these are leptodactylous forms (Figures 26, 59). A complete treatment of this new species will be given elsewhere.
A single trackway found by John Colagrande in the uppermost Towaco Formation of Towaco, New Jersey represents the sole known post-Passaic Formation occurrence of Rhynchosauroides in the Newark Supergroup (Figure 59). It is described here because it should also occur at Riker Hill. During the Triassic, there were a very wide range of lepidosauromorph reptiles that could have made Rhynchosauroides-type footprints including the Trilophosauria, Rhynchosauria, Protorosauria, and the Lepidosauria, but by the Early Jurassic only the Lepidosauria remained. The Lepidosauria include the Rhynchocephalia (Sphenodontia; which includes the living Tuatara) and the Squamata (lizards and snakes). Small members of either group could have made these Jurassic Rhynchosauroides, although we note that an appropriate sized sphenodontian, Clevosaurus bairdi, is one of the most abundant skeletal forms known from the earliest Jurassic of Nova Scotia (Sues et al., 1994).
The probable-crocodylomorph track Batrachopus deweyii is the most common quadrupedal ichnite in the Newark Supergroup Jurassic, and is common at Walter Kidde Dinosaur Park as well (Figure 59). The form genus is diagnosed as a small quadrupedal form with a five-toed manus and a functionally four-toed digitigrade pes. Skeletal examples of crocodyliforms have been found in the Early Jurassic Portland Formation of Massachusetts (Stegomosuchus longipes; Walker, 1968) and the McCoy Brook Formation of Nova Scotia (Protosuchus micmac; Sues et al., 1996). The crocodyliforms of the earliest Jurassic, such as Protosuchus, were rather different in their overall appearance from living crocodilians (crocodiles and alligators). They were small, slender, short-snouted, and lightly armored, with no obvious aquatic adaptations. Their skeletons had elongate limbs, which, based on Batrachopus, appear to have carried the body in a high walk, with the legs more or less under the body. Similarly, they were digitigrade most of the time, while modern crocodilians walk plantigrade nearly all the time. In contrast to the large lunging semi-aquatic modern crocodilians, the makers of Batrachopus were small, fully terrestrial, active, fast predators.
By far the most abundant dinosaur tracks at the Riker Hill quarry are bipedal three toed forms (Figure 60) that never have manus impressions. The smallest ones (1.5-15 cm long) tend to be very narrow, with a distinctly elongate middle digit (III); the largest ones (20-30 cm long ) tend to be broad, with a relatively short digit III. Only very rarely is there an imprint of the tip of digit I (the hallux). The in-between sized forms are intermediate in all proportions. These types of tracks have been traditionally called Grallator (the smallest forms), Anchisauripus (the intermediate-sized forms), and Eubrontes (the largest forms) (e.g. Lull, 1953). The phalangeal formula and general proportions are consistent with small to medium-large theropod dinosaurs. One would think that because these kinds of tracks are very common, they must be well known and understood; unfortunately the reality is a nomenclatural quagmire badly in need of revision.
This nomenclatural mess has two origins. First, the history of the nomenclature is sloppy and in desperate need of revision: most of what are proffered in the literature as the type specimens are not, and virtually every named taxon has a tortured and confused history (e.g. Olsen et al., 1998); even the commonly-used names are not necessarily valid by strict application of nomenclatural rules! Second, organisms change in shape as they grow. This is termed "allometry" and is caused by different growth rates in different parts of the body, and we have argued that much of the variation in shape in these footprints can be explained by growth alone.
For over 90 years the standard references for Newark Supergroup tracks of Early Jurassic age have been the works of Lull (1904, 1915, 1953), essentially revisions of Hitchcock's monographs (1858, 1865). As defined by Lull's concept of their type species, the major differences between the genera Grallator, Anchisauripus, and Eubrontes, apart from size, are the ratio of length to width, the relative projection and length of digit III, and the angle of divarication between digits II and IV. When considering the type specimens (as identified in Lull, 1953) alone the genera appear morphologically quite distinct. However, when we attempt to place other specimens in these taxa we find that there are a multitude of intermediate forms. As suggested by Olsen (1980b) and Olsen et al. (1998), all of the forms lie on a morphological trend varying in a consistent way with size. It is not at all apparent to us that it is possible to objectively isolate portions of this trend as separate genera. As the size of the footprint increases, the relative width of the footprint increases, as does the divarication between digits II and IV; there is thus a decrease in the projection of digit III beyond the outer two toes. The same general proportional changes can be seen between the skeletons of the small ceratosaurian theropod Coelophysis (Colbert, 1989) and the much larger ceratosaur Dilophosaurus (Welles, 1984). The larger specimens of Coelophysis fit the proportions of large Grallator or small Anchisauripus. If these footprints cannot be objectively split up into several genera, they should all be give the earliest proposed valid name, which should be Eubrontes (Ornithichnites Hitchcock 1836) (Olsen et al, 1998). But, pending a revision of these genera (underway by ECR), we refer to them the same way as did Lull (1953): as Grallator, Anchisauripus, and Eubrontes, and collectively as grallatorids.
Among the many grallatorid tracks from Riker Hill are some very small examples (Figures 60). These tracks are among the smallest dinosaur footprints known from anywhere geographically and temporally. A nice gradational series of tracks intermediate between the smallest grallatorids and the largest Eubrontes have been found at the site (Figure 60).
Remains of small theropods have been found in Jurassic Newark Supergroup strata in the Portland Formation of Connecticut and Massachusetts and the McCoy Brook Formation of Nova Scotia (Colbert and Baird, 1958; Olsen et al., 1987; Sues and others, 1987; Talbot, 1911). A single large tooth fragment found within a Eubrontes track at Walter Kidde Dinosaur Park (unit 18) is the only skeletal material of theropods yet found in the Newark basin (Olsen, 1995).
The ichnogenus Anomoepus (Hitchcock, 1848) is the only other common dinosaurian track form that has been positively identified from the Riker Hill quarry. This genus is distinguished in bipedal walking tracks by having the metatarsal-phalangeal pad of digit IV nearly in line with digit III, having a short digit III for the size of the foot, and more divaricate pedal digits than similar-sized grallatorids. Sitting traces are fairly common, in which the entire pes including the metatarsus is impressed, as is the five-toed manus. The wide range of sizes of Anomoepus present at Roseland demonstrate the range of variation in the genus, although there is far less variability than is seen in the grallatorid forms described above. We have not, however, found criteria for recognizing more than one footprint species, and therefore we synonymize all Anomoepus species from the Newark Supergroup with Anomoepus scambus, the type species of the genus from the Turners Falls Formation of Massachusetts (Olsen and Rainforth, 2002). Also unlike Grallator, there seems to be little change in shape with size, except perhaps for a slight relative shortening of digit III with increasing foot length.
The structure of the inferred pedal skeleton is compatible with either a theropod or an ornithischian dinosaur; however, the hand flatly rules out a theropod track maker, because all five digits remain well developed, albeit short. In contrast to theropods (in which manual digits I-III are dominant, IV and V eventually being lost), manual digits IIIV are dominant in Anomoepus - the beginnings of a trend seen clearly in more advanced ornithischians (e.g. hadrosaurs), in which the outer digits are reduced and finally lost. Anomoepus was therefore probably made by a small, herbivorous, relatively primitive ornithischian dinosaur, similar to Lesothosaurus or some other "fabrosaur". Scrappy bones and isolated teeth of "fabrosaurs" have been found in the McCoy Brook Formation of Nova Scotia (Olsen et al., 1987; Sues et al., 1987).
Anomoepus is characterized by a less well-developed pad structure in the pes than grallatorids. Although the skin texture is very similar to grallatorids, the pads tend to be separated by much smaller narrower pads, suggesting that some flexing of the foot was common. The pads on the hand show this very well, and in fact appear to show creases or grooves over the articulations, which is to be expected in a hand used more for grasping than walking. Thus, it seems likely that Anomoepus used its hands, and sometimes its feet, to grasp things - probably branches; a reasonable scenario for a small herbivorous dinosaur.
One of the most unusual aspects of the Riker Hill assemblages is the unusually large number of presumably-juvenile Anomoepus tracks. One layer in particular in the upper part of unit 18 was covered in many small and a few larger Anomoepus. The association of the uncommon larger forms with the much more abundant smaller forms suggests, but of course does not demonstrate, herding of young. The smallest Anomoepus tracks are, like the tiny Grallator, among the smallest dinosaur footprints known. Unfortunately, also like the tiny Grallator, these tracks lack pads and thus the assignment to Anomoepus can only be tentative. One of the minute Grallator trackways is from the same bedding plane as the abundant "baby Anomoepus". The meaning of the diminutive carnivore among the baby herbivores is unknown.
The track assemblage at Walter Kidde Dinosaur is typical for the Towaco Formation, and is very similar to all of the Newark Supergroup assemblages that postdate the Triassic-Jurassic boundary. They are the post-catastrophe assemblages, largely consisting of survivors of the end-Triassic mass extinction.

This area is often flooded
This area is often flooded by waters from the Passaic River. Control of this flooding was the goal of the proposed Passaic River diversionary tunnel, the planning stages of which resulted in the collection of over 10 k of short cores (each ~100 m) spanning the upper Passaic Formation and most of the succeeding Jurassic Formation (Fedosh and Smoot, 1988; Olsen et al., 1996b) collected by the Army Corps of Engineers (ACE cores).

Cut in Hook Mountain Basalt.
Immediately north in the same ridge is the cut for Interstate Route 80 that comprises the type section of the Hook Mountain Basalt (Olsen, 1980c).

Gap in ridge for Preakness Basalt
Gap in ridge for Preakness Basalt through which the Hudson River flowed.

Crossing Passaic River

Gap on left in Orange Mountain Basalt for Hudson River.

On right are outcrops of the Orange Mountain Basalt
On right are outcrops of the Orange Mountain Basalt and underlying uppermost Passaic Formation. This is section E of the type section of the Passaic Formation of Olsen (1980c). A series of faults cut the Orange Mountain Basalt here, some of which are visible in the cut on the left, just west of the Passaic - Orange Mountain Basalt contact. Triassic-Jurassic boundary is somewhere within a few meters below contact.

Garrett Mountain visible on right (south),
Garrett Mountain visible on right (south), Passaic Falls is on the left (north). The upper Passaic Formation of Rhaetian age (latest Triassic) has produced near here a series of well preserved skeletons of the highly specialized procolophonid reptile Hypsognathus (Colbert, 1946) including the type specimen, which was found just south of here (Gilmore, 1928). About one skeleton or skull is found in the northern Newark basin per decade.

Section D of type section of Passaic Formation (Olsen, 1980a,c).

Section C of type section of Passaic Formation (Olsen, 1980a,c).

Section B of type section of Passaic Formation (Olsen, 1980a,c).

Section A
Beginning of type section of Passaic Formation (section A, Olsen of Olsen, 1980a,c) in open cuts for Route 80.

Open cut in Palisade sill and Lockatong hornfels.
According to Van Houten (1969), hornfels include grosularite, andradite, prehnite, and diopside varieties. Lockatong cycles fossiliferous, as usual, and these cycles may tie in with Granton Quarry cycles (Stop 4). Geochemistry of the sill at this cut described by Naslund (2000).

Strike ridge of the Palisade sill
Turn left onto US Route 9W north and follow along the crest of the strike ridge of the Palisade sill.

End of Field Trip