Newark supergroup

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Map with outcrops of the Newark supergroup (black)

The Newark Supergroup ( English Newark Supergroup ) is a lithostratigraphic unit of the rank of a supergroup , which, cumulated across basins, comprises a maximum of around 15,000 meters thick sequence from at least the Middle Triassic to the Lower Jurassic . It forms the predominantly siliciclastic-sedimentary filling , partly alternating with basalts, of numerous larger and smaller fossil sedimentary basins on the east coast of the USA and in the maritime provinces of Canada . The deposition of these sediments and the formation of the corresponding basins and the associated basaltic volcanism are closely related to the early phase of the opening of the Atlantic Ocean . The sub- Jurassic layers of the Newark supergroup are of outstanding importance in terms of the history of science as the horizons for the discovery of the historically first dinosaur tread seals and bones, the first largely completely preserved fish fossils and the first Mesozoic insects in North America .

Historical

The name Newark Group was coined by William Charles Redfield in 1856 . Previously, the early Mesozoic, often reddish colored siliciclastics of the east coast states of the USA * were given various names due to the presumed age equality with facially similar sequences in the sediment tradition, especially from Great Britain . So initially as Old Red Sandstone and from the 1830s often as New Red Sandstone † . Redfield found the name he chose to be more appropriate because there was increasing paleontological evidence that these strata are younger than the New Red Sandstone of Great Britain. Although this turned out to be only partially correct in retrospect, the name Newark - initially also in the combinations Newark System and Newark Series - prevailed in the 20th century. Israel Russell favored it in a monograph published in 1892 because of its regional reference, with no inherent assumption about a correlation with a particular rock unit of Europe. As such, he already complied with the naming rules of modern lithostratigraphy. Russell (1892), based on James Dwight Dana (1875) , among other things , also added the outcrops in the Canadian maritime provinces to the distribution area of ​​the " Newark System ".

After the establishment of the " Theory of New Global Tectonics " at the turn of the 1960s to the 1970s, the realization matured that the genesis of the basins and thus also the deposition of the sediments of the Newark group with the breakup and formation of the western Pangea of the Atlantic Ocean. see e.g. B. 

In 1978, Paul Eric Olsen , who had just received his geology bachelor's degree from the Peabody Museum in Yale , proposed that the Newark group be promoted to the rank of supergroup , since separate groups had been set up for some of the basin fillings (including the Fundy group and Dan River group; see pool names below ) and the term "Newark group" was therefore no longer suitable as an umbrella term for all pool fillings . In 1984, Olsen officially applied for this upgrade and accepted it by the United States Geological Survey . Numerous publications in the following decades ensured that the name Olsen is inextricably linked with modern, in particular sedimentological, stratigraphic and paleontological research of the Newark supergroup.

* "[...] the extensive sandstone formation of the Connecticut river valley; the small and isolated basin on the Pomperaug river near Southbury, Ct .; the New Jersey Sandstone, extending from the border of the Hudson river, southwesterly, to the interior of Virginia; and, also, the formation known as the coal rocks of Eastern Virginia "-" the extensive sandstone formation of the Connecticut River Valley; the small and isolated basin on the Pomperaug River at Southbury, Ct .; the New Jersey sandstone that extends from the Hudson River to Virginia and the formation known as the Coal Mountains of Eastern Virginia "
† A detailed list of the names used in the 19th century can be found on p. 16 ff. In Russell (1892).

distribution

Monotonous sequence of marginal lacustrine-fluvial fine-grain siliciclastics of the ball-bluff subformation of the bull-run formation (Passaic formation according to the new nomenclature; Chatham group) of the Culpeper basin in a quarry near Manassas , Virginia

The rocks of the Newark supergroup bite out discontinuously in a strip around 100 kilometers wide between the Appalachian Mountains and the coastal plain, which extends from northern South Carolina to the northwest end of Nova Scotia (Chedabucto Bay). They are distributed over seven larger and around 20 smaller and very small structural remnants of sedimentary basins , which, in principle, striking southwest-northeast, parallel to the structures of the Appalachians , are sunk into the pre-Mesozoic basement in the form of half-trenches . The names of the larger pools are as follows (from southeast to northwest):

Deposits that, due to their age and geological context, have a close genetic relationship to the Newark supergroup, can also be found from Florida and Georgia (South Georgia Basin) to Newfoundland (Jeanne d'Arc-Flemish Pass Basin) in the subsurface of the coastal plain and the upstream Shelves . In Nova Scotia, “ on-shore ” outcrops and “ off-shore ” deposits even merge laterally into one another.

Geographical and regional geological framework

Plate tectonic reconstruction of the western Tethys region and adjacent areas for the youngest Triassic ( Rhaetian ). Green lines mark continental areas with stretch tectonics.

The chain of basins, in which the sediments of the Newark supergroup and their buried equivalents were deposited, was formed from the Middle Triassic in the course of an expansion of the earth's crust in the North American-North African section of the largely eroded Variscan mountain belt . The North American part of the corresponding system of rifts ( Central Atlantic Margin , abbreviated to CAM), which is a Mesozoic analogue of the Great African Rift System , is known as the Eastern North American Rift System (ENARS). The expansion tectonics is the regional expression of the breakup of the supercontinent Pangea and represents the initial phase of the opening of the Central Atlantic.

The basalts, which are included in the sedimentary sequence in the area of ​​the Triassic-Jura boundary, are closely related to this plate tectonic event. The basalts are part of the Central Atlantic Magmenprovinz (Engl. Central Atlantic Magmatic Province abbreviated CAMP ), which also extends to Northwest and West Africa extends as well to the northeast of South America.

With the transition to the ocean floor spreading (“ rift to drift ”) in the actual Central Atlantic Basin in the further course of the Lower Jurassic, the continental crustal expansion and thus also the subsidence and uptake of sediments in the basins of the Newark supergroup ends . The rift basins in eastern North America even experience a slight inversion in this phase, in which the sense of movement of the previous faults is reversed and wrinkles are formed in some of the basin fillings . The cause of this compression phase is assumed to be the onset of the “ridge push” (see causes of plate tectonics ) at the Atlantic expansion zone and / or inertial forces that counter the movement of the plate and originate from the North American continental block ( Laurentia ). Since then, both the most recent layers of the basin fillings and the thin deposits that were probably originally present between the remains of the basin today ( depocenters ) have been removed again due to their more or less permanent location above the erosion base .

stratigraphy

Red siliciclastic from the Blomidon Formation (Passaic Formation according to the new nomenclature; Chatham Group), overlaid by North Mountain Basalt (Talcott Formation; Meriden Group), Fundy Basin, Five Islands Provincial Park, Nova Scotia

The internal lithostratigraphic organization of the Newark supergroup has undergone multiple changes over the past few decades. At the end of the 1980s, individual formation and group names were still being used to fill each larger pool . A total of 6 groups and 57 formations were distinguished (the formations of smaller basins were not combined into groups). In the course of a revision by Weems & Olsen (1997), the number of groups held up to that point was reduced from nine to three and all formations not yet assigned to a group were placed in one of these three groups. In a subsequent revision (Weems et al., 2016), when the number of groups was increased to four, the number of formations was reduced to 16, largely over-basin units. Accordingly, the Newark supergroup is structured as follows (from young to old):

  • Longmeadow sandstone
  • Boonton formation

laterally interlocked with both:
Mount Toby conglomerate

  • Meriden group (youngest Rhätium - older Hettangium)
    • Hampden formation B 
    • East Berlin formation
    • Holyoke formation B 
    • Shuttle Meadow Formation
    • Talcott Formation B 
  • Chatham group ( Carnium - Rhätium)
    • Passaic formation
    • Lockatong formation
    • Stockton formation
    • Doswell formation
  • Acadia Group (restricted to the Canadian Maritime Provinces  ;? Oberperm ,?  Anisium -?  Karnium )
  • Evangeline-Formation (formerly Evangeline-Subformation of the Wolfville-Formation; see Sues & Olsen (2015))
  • Economy-Formation (formerly Economy-Subformation of the Wolfville-Formation; see Sues & Olsen (2015))
  • Honeycomb point formation

with an unclear relationship
to the other formations:
Chedabucto formation

** For an almost complete overview of current and obsolete unit names see Weems et al. (2016: Table 2 / p. 116 ff.).
B. basalt- and / or basalt-tuff-dominated units

In North Carolina and further south, basin fillings are restricted to the Upper Triassic. As the oldest member of the supergroup, the lower part of the Wolfville Formation ("Lower Economy beds"; at the time the oldest layers of the Chatham group) of the Fundy Basin, which reaches down to at least the upper Middle Triassic, was still considered in 1997. The following are a small scale at the Fundy Bay coast of New Brunswick open-minded, and also originally as mitteltriassisch looked layers of the so-called Honeycomb-point formation, which are not mentioned in the 1997 revision, due to paleomagnetic and palichnologischen findings than likely oberpermisch classified and has been correlated with the clear Permian Ikakern formation of the argan basin in Morocco. The honeycomb point formation could have been deposited before the onset of the ENARS expansion tectonics. The most recent deposits are generally considered to be the uppermost layers of Longmeadow sandstone (formerly Upper Portland Formation, Agawam Group) in the Hartford (partial) basin. However, their exact age is uncertain. In more recent publications (2000 ff.) They are mostly placed in the Sinemurium , while at the end of the 1980s a late subjurassic age ( Toarcium ) was estimated.

Lithologies

Handpiece of the basal conglomerate layers of the New Oxford Formation (Stockton Formation according to the new nomenclature) of the Gettysburg Basin
Disturbed silt mudstones with layers of thin fine sandstone layers, Blomidon Formation (Passaic Formation according to the new nomenclature; Chatham Group) of the Fundy Basin, exposed in the coastal cliff southeast of Parrsboro , Nova Scotia

Sedimentary rocks - facies and cycles

The sequence of the Newark supergroup consists mostly of reddish siliciclastic rocks that were deposited as sediments either by rivers (fluviatil) or in lakes (lacustrine / limnic). North of North Carolina, in the Triassic section of the basin fillings, a three-way division of the sequence can be identified: a basal, predominantly fluvial part is followed by an interval dominated by lacustrine deep-water deposits with often gray or black layers, followed by an interval with predominantly lacustrine, reddish deposits follow, whereby the boundaries between these intervals are not of the same age (isochronous) across the pelvis. In the Lower Jurassic sections of the basin fillings, no comparable typical vertical facies sequence can be identified.

Intervals with dominant lacustrine sedimentation show a laterally concentric structure. The finest-grained deposits ( clay-silt rocks ) are found in the relatively central basin areas with the highest subsidence due to the half-ditch geometry in the direction of the basin rim fault. With this actual lacustrine facies, sandy fluvial and deltaic sediments interlock towards the outside, which merge into conglomerates in the direction of the basin rim fault. Vertically, many of the mighty sequences of the actual lacustrine facies show a cyclical structure that reflects Milanković- controlled climatic fluctuations. The Van Houten cycles that can be observed on the outcropping scale are lacustrine transgression - regression cycles that can be correlated across the basin and correspond to the roughly 20,000-year precession cycle. The McLaucghlin cycles , which can only be perceived on a map scale and comprise around 20 Van Houten cycles, represent longer-term but more extreme climatic fluctuations in the 400,000-year eccentricity cycle. A distinction is made between three sections ( divisions ) within a Van Houten cycle :

  1. transgressive section - small powerful, with rather massive formed base, for hanging wall towards decreasing number of dry cracks and root tracks, accompanied (with distinct formed layering Non are atypical carbonate moving water deposits of the bank area So includes a transgressive sequence in the Passaic formation. in-situ -erhaltene , fusinit ized, d. h. may charred in a forest fire, small snags that of stromatolites are overgrown that turn into oolitic embedded sand, and everything is black siltstones with increasing and decreasing lamination , English. "pinch and swell lamination" superimposed.); documents increasingly humid climate
  2. Elevated section - thin, often gray or black, “schisty” -plated, partly laminated silt clay stones; documents a period with a very humid climate; dark, laminated layers show deep (up to 80 meters) lakes with little water circulation and basin-wide extension (the lakes probably extended well beyond the edges of today's structural remains of the basin, possibly even the "largest lakes of all time")
  3. regressive section - thick, with relatively clearly developed stratification at the base, the number of dry cracks and root traces increasing towards the hanging wall, accompanied by a more massive appearance of the rock; documents increasingly dry climate; represents relatively shallow, less extensive and regularly at least partially dry waters

Layers of fluvial origin are mainly interpreted as evidence of intertwined rivers . Corresponding deposits are mostly in the form of reddish-brownish, gravelly and / or arcotic sandstones . Only a few fluvial sediments show features that indicate deposition by meandering rivers , although this could be an artifact that is due to a relatively poor exposure situation. The conglomeratic layers of the basin margins are at least partly fanglomerates , i.e. deposits of alluvial fans in which coarse, unsorted erosion debris from the basement was deposited, which was washed in from the terrain on the other side of the trench margin fault, which at the time was more in relief. Especially in the Doswell and Lockatong Formations (according to the new nomenclature) of several mostly smaller basins in North Carolina and Virginia, associated with both fluvial and lacustrine deposits, coal seams with thicknesses between 5 centimeters and 2 meters occur.

Aeolian sediments ( sand dunes ) are also relatively widespread in the Fundy Basin .

Basalt of the Preakness Formation (Holyoke Formation according to the new nomenclature; Meriden Group) superimposed on sandstones of the Feltville Formation (Shuttle Meadow Formation; Meriden Group) of the Newark Basin, east flank of Preakness Mountain (High Mountain Park Preserve), New Jersey

Volcanites

Hand pieces of basalt from the Hook Mountain Formation (Hampden Formation according to the new nomenclature; Meriden Group) of the Newark Basin, weathered brown, collected on Third Watchung Mountain in Passaic County, New Jersey

The volcanic rocks of Newark supergroup include Tholeiitbasalt cover and corresponding pyroclastic sediments . They vary only slightly in their relative chemical composition and mineral composition, with each of the three volcanite-dominated formations (according to the new nomenclature) having a specific composition. These compositions essentially correspond to the "chemotypes" used by Weigand & Ragland (1970) for early Jurassic dolerites in eastern North America and by Tollo & Gottfried (1989) for the Hook Mountain basalt (Hampden formation according to the new nomenclature) of the Newark Basin identified. Accordingly, the basalt of the Talcott Formation corresponds to the type of titanium-rich, quartz-normative tholeiite (HTQ; more than 1.0 wt.% TiO 2 ), the chemically relatively variable basalt of the Holyoke Formation corresponds to the type of iron-rich quartz-normative tholeiite (HFQ; 13–15 wt .-% total Fe 2 O 3 ) and in the Culpeper Basin and Newark Basin also the type of low-titanium, quartz-normative tholeiite (LTQ; 0.7-0.8% by weight TiO 2 ) and the basalt of the Hampden Formation corresponds to this Type of iron- and titanium-rich quartz-normative tholeiite (HFTQ; more than 15 wt.% Total Fe 2 O 3 with more than 1.3 wt.% TiO 2 ).

From clear differences in the trace element signatures of the basalts of the three formations, in particular the distribution of so-called incompatible elements (including REE ), i.e. elements that remain in the melt for a very long time because their ionic radii do not match the crystal lattice of the minerals that prefer to crystallize out, and their Content and distribution in the melt is consequently not influenced by fractionation processes, it has been concluded that the magmas of the three formations do not come from the same source, but from different sources.

Fossil guide

Examples of distinctive fossils from the strata of the Newark supergroup on display at the Carnegie Museum of Natural History

The Newark supergroup is now considered to be one of the richest continental strata series in the world. Depending on the sedimentary facies and depositional environment it contains mainly terrestrial vertebrates (tetrapods), various fish (predominantly but more or less "primitive" ray-finned fishes from the groups Palaeonisciformes or semionotiformes ), terrestrial and aquatic arthropods , fresh water mollusks , plants, fossil footprints of land vertebrates and trace fossils of invertebrates in various states of preservation. The sandy-conglomerate fluvial-alluvial marginal facies contain numerous terrestrial vertebrates, but often only in poor to moderate preservation (i.e. more or less severely abraded individual bones and bone fragments, which can only rarely be determined or diagnosed at the level of the genus or species ). Plant residues only occur there in the form of unidentifiable chaff. The still water facies of the central basin areas, on the other hand, contain plants, invertebrates, fish and some (aquatic and terrestrial) terrestrial vertebrates in good to exceptionally good preservation ( conservation deposits ). Step seals can be found in the finer-grained fluvial deposits ( alluvial plain ) and above all in the lacustrine deposits near the banks, periodically dry areas, whereby, following a general "tradition," they are hardly or not at all associated with fossil bones.

The vertebrate faunas show on the one hand relationships to faunas of the same age in the Colorado Plateau (Chinle Formation, Kayenta Formation) and European-North African ("British fissure fills", Germanic basin , Argana basin ) and Chinese faunas, but also on the other Relations with Gondwanian faunas (especially those of the Paraná - Karoo basin complex in southeastern South America and in southern Africa).

Since it also includes fossil-bearing layers of the Lower Jurassic in the northern part of its range, the Newark supergroup offers an insight into the Triassic Jurassic mass extinction and the subsequent recovery phase.

Middle Triassic

Middle Triassic vertebrate fossil societies occur only in the Fundy Basin. A distinction is made between an older one in the economy formation and a younger one in the Evangeline formation. The older one contains scattered remains of " primeval amphibians " that cannot be clearly identified at the level of the genus , more precisely trematosauroids (previously identified as Aphaneramma or Cosgriffius ) and capitosauroid temnospondyles . Amniotes are represented by procolophonoids and various representatives of the Archosauriformes , of which only Tanystropheus can be clearly identified by means of a single cervical vertebra.

A similar but clearly distinguishable fauna includes the Evangeline lineup, with the metoposauroiden Temnospondylen Metoposaurus bakeri and Procolophonoiden Acadiella psalidodon , Haligonia bolodon and Scoloparia glyphanodon and the narrow trilophosaurus congeners Teraterpeton hrynewichorum , "higher" (hyperodapedontinen) Rhynchosauriern , basal terrestrial crocodile lines -Archosaurs from the group of the aetosaurs and the Rauisuchier and with Arctotraversodon plemmyridon also a reliably identifiable representative of non-mammal cynodontics . Material that was previously assigned to dinosaurs probably belongs to other archosaur groups already mentioned above and only in some cases to non-dinosaur ornithodires . In contrast to Weems et al. (2016), Sues & Olsen (2015) date the Evangeline formation (or the Evangeline subformation of the Wolfville formation) not in the late Middle Triassic ( Ladinian ), but in the early Upper Triassic ( Carnic ).

Upper Triassic

Incomplete skeleton of Hypsognathus fenneri from the Passaic Formation (Nor) of the Newark Basin, New Jersey
Skull of " Colobops noviportensis " from the Passaic Formation of the Hartford-Deerfield Basin, Connecticut

Terrestrial vertebrate faunas in fluvial deposited layers in the Upper Triassic of the Newark supergroup are dominated by procolophonoids (with Hypsognathus fenneri as the last representative of the group in terms of geological and evolutionary history), phytosaurs, aetosaurs, rauisuchier and hyperodapedontine rhynchosaurs. Dinosaurs form only subordinate fauna elements and are represented by fragmentary remnants of (probably exclusively coelophysoid ) theropods that cannot be identified in detail . The previously postulated occurrence of " prosauropods " has not been proven for the Upper Triassic in all of North America due to a lack of diagnostic material. The also previously postulated occurrence of ornithics (" Fabrosauridae ", " Galtonia gibbidens ", " Pekinosaurus olseni ") is now generally doubted even for the Upper Triassic. The relationships between the 1993 find of the skull of a small juvenile reptile from the New Haven Arkose (Passaic formation of the Hartford-Deerfield Basin) are also controversial. Originally classified as an indefinable sphenodontic animal, it was re-described in 2018 as a basal stem group archosaur under the name Colobops noviportensis , whereupon the interpretations made in this work and the conclusions drawn from it were immediately questioned with reference to the state of preservation of the material.

Historical drawing (1847) of a specimen of Dictyopyge macrurus from the Doswell Formation (Unter-Karn) of the Richmond Basin, Virginia

Fossil-bearing swamp deposits that are relatively clearly identifiable as such (defined as dysoxic fine-grained deposits in densely planted parts of still waters) are restricted to the southern basins of the Newark supergroup and to the lower Upper Triassic ( Carnian ). In the lower Carnium (Doswell Formation) of the small Richmond Basin (Virginia), the oldest well-preserved macroflora of the sequence occurs. It is of ferns (u. A. Clathropteris ), horsetails (u. A. Neocalamites , Equisetites ) and cycads ( Macrotaeniopteris , Taeniopteris , Pterophyllum dominated). Associated with it is a fish fauna in which the species Dictyopyge macrurus (Palaeonisciformes, Redfieldioidei) is by far the most common species. This species is endemic in the small basins in eastern Virginia and there “omnipresent” in all fish-bearing strata, not just in the lower Carniola. This is where the fish faunas in these basins differ from all other Upper Triassic fish faunas in the Newark supergroup. Younger (but sometimes uncertain dated) contain Carnic Landwirbeltierfaunen in (alleged) swamp deposits of these basins non-mammale Cynodontier (so the Traversodontiden Boreogomphodon jeffersoni , the Eucynodontier Microconodon tenuirostris and Cynodontier unclear position Dromatherium sylvestre ), Dicynodontier ( placerias ), "higher" Crocodile - Tribe group representatives ( Carnufex carolinensis and the Sphenosuchier Dromicosuchus grallator ), phytosaurs ( Rutiodon , dominant in the Middle Carniola), the archosaurs Uatchitodon, known only from their poisonous teeth, as well as Temnospondyles traditionally classified as Metoposaurids. The Temnospondyle Calamops paludosus , which originates from possible swamp deposits of the Newark Basin and is also traditionally classified as Metoposauroids, is now assigned to the Trematosauroids .

From a flat-open acustrine facies of the Doswell Formation of the Taylorsville Basin (Virginia), the crocodile-like, but very peculiarly built basal trunk group archosaur Doswellia kaltenbachi was described.

The vast majority of the better preserved fossil specimens come from deep lacustrine layers in the Van Houten cycles of the central pelvic facies (see above ). Abundant allochthonous macro flora with ferns, horsetail, cycads and conifers do not generally occur in it, but presumably only where the banks were relatively close and the plant material introduced could easily reach the deeper lake regions, i.e. H. only in the narrow of the larger basins such as the Dan River-Danville Basin. The same apparently applies to the occurrence of insects. In the Ober-Karn or Unter-Nor (Cow Branch or Lockatong Formation) of the Danville Basin, the Solite Quarry near Eden (Leaksville Junction, North Carolina) is known as a single Upper Triassic site in which completely and detailed aquatic and terrestrial insects are common. By 2007, about 50 different kinds of goods in this locality flying insects have been identified, focusing on 11 major groups ( cockroaches , beetles , Diptera , scorpion flies , dragonflies , grasshoppers , stoneflies , aphids , cicadas , bugs and thrips spread). By 2010, a total of 4,000 specimens had been collected during the excavations. In addition, the geologically oldest real spider has been described from this locality .

From the higher trophic levels , primarily fish have survived in the deep water facies. A total of tens of thousands of specimens have been collected from various excavation sites. General representative of the type genus dominate the semionotiformes Semionotus , in the higher Upper Triassic also dominate either the Palaeoniscoide Turseodus or the coelacanth Diplurus (=  Osteopleurus ) newarki . Land vertebrates are rarer but still relatively common, mainly represented by the peculiar diapsids Tanytrachelos ahynis (a tanystropheid) and Hypuronector limnaios (a drepanosaurid with a controversial ecology) as well as the diapside gliding reptile Icarosaurus siefkeri and some remains of phytosaurs. An important source of all these reptiles is the now defunct “Granton Quarry” in the township of North Bergen , New Jersey (Lockatong Formation, Newark Basin).

Lower Jurassic

Basalt breccia of the McCoy Brook Formation (Shuttle Meadow Formation according to the new nomenclature; Meriden Group), Wasson Bluff, Fundy Basin, Nova Scotia. In such breccias, interpreted as fossil rubble cones , there are numerous fossilized bones of terrestrial vertebrates.

The only abundant sub-Jurassic terrestrial fossil fossil record in eastern North America is Wasson Bluff near Parrsboro in the Fundy Basin. In the local fine sand to brecciated / conglomeratic pool edge deposits and silty clayey distal equivalents (McCoy Brook Subformation the shuttle Meadow formation, lowermost Hettangian) dominate Sphenodontier ( Clevosaurus bairdi ) and Protosuchier ( Protosuchus micmac ) and Semionotus and cf. Hybodus . Dinosaurs form only a subordinate element of the fauna and are primarily represented by an alleged "prosauropod" (cf. Ammosaurus or " Fendusaurus eldoni " cf.  ). There are also sparse remains of small theropods and ornithics. Amniotes of the synapsid line are represented by non-mammal cynodontics from the groups Tritheledontidae ( Pachygenelus cf. monus ) and Tritylodontidae ( Oligocyphus ).

The first discoveries of “prosauropods” ( Anchisaurus polyzelus ) made in 1818 in alluvial / fluvial sandstones of the “Connecticut Valley” (Portland group of the Hartford-Deerfield basin) were the first historically, albeit more than 30 years before the establishment of the Taxons Dinosauria by Richard Owen , initially misinterpreted finds of dinosaur bones in North America. The remains of a coelophysoid theropod ( Podokesaurus holyokensis , original material destroyed in a fire in 1916) come from roughly the same layers and the same area .

Remains of insects are known from the clayey-silty layers of the Newark and Hartford-Deerfield basins, which, according to the sedimentological findings, were deposited in alluvial plains or shallow lakustrine, which mainly originate from beetles (mostly isolated elytra ). In two localities in the Turners Falls sandstone (East Berlin formation according to the new nomenclature; early Hettang) of the Deerfield (partial) basin near Turners Falls in Massachusetts, suspected beetle larvae occur in great density, which were the first Mesozoic insect fossils in 1850 proven to have been collected in North America. They were first described in 1858 under the name Mormolucoides articulatus . At that time, these larvae probably died en masse during the dry season due to the increasing salinity of the shallow water areas.

Historic photograph (1905) of a specimen of Redfieldius gracilis from the Lower Jurassic Hartford-Deerfield Basin

From the deep lacustrine facies of the lower Jurassic strata of the Newark supergroup, tens of thousands of more or less complete fish have been recovered. With the exception of a few isolated teeth and individual bones, which probably come from dinosaurs, it contains almost no remains of terrestrial vertebrates. The fish faunas are dominated by various endemic species of Semionotus and also include representatives of the genera Redfieldius (type genus of the Palaeonisciformes subgroup Redfieldioidei), Ptycholepis (type genus of the basal ray fins group Ptycholepidiformes ) and the coelacanth Diplurus longicaudatus . These deposits also have a high scientific and historical value, because they are the origin of the oldest known finds of articulated fossil fish in the USA. The plants that have survived in the Jurassic deep water facies are represented by isolated but well-preserved shoots, leaves and twigs of ferns, cycads ( Otozamites ) and conifers.

Trace fossils

The dating of the Honeycomb Point Formation as Upper Permian is based on palichnological findings, but the tread seals in question, which are similar to the Permian forms Dimetropus and Hyloidichnus , are too poorly preserved for an exact determination and moreover not directly accessible.

The fluviatile and especially the lacustrine-deposited Upper Triassic and Lower Jurassic layers of the Newark supergroup in the northeast of the USA have been world-famous for their tetrapod tracks and treads since the 19th century. With regard to the frequency distribution of the terrestrial vertebrate taxa presumably represented by the step seal, the trace fossil record differs in part significantly from the body fossil record.

In the Upper Triassic, for example, the trace genera Atreipus , Grallator , Anchisauripus and Evazoum , the more basal Dinosauropmorpha (e.g. Silesauridae ) and "real" dinosaurs are assigned as causers, compared to the bone and tooth material handed down from Dinosauromorpha. The trace genera Rhynchosauroides (Sphenodotiertrittsiegel / -fährten), Gwyneddichnium (Tanystropheidentrittsiegel / -fährten) as well as Procolophonichnus and Cynodontipus (step seals / -tracks or burrows of procolophonoids) are rather underrepresented. Temnospondyle traces are not represented at all in the tradition of the step seal. The frequency of the Apatopus phytosaur track roughly corresponds to the frequency of traditional phytosaur bones .

Several crossing theropod tracks ( Grallator ) as spills on the underside of a layer of the "Portland Arkose" (Lower Jurassic) of the Hartford Basin ( Middletown, Connecticut ). The cause of the associated step seal could have been the Podokesaurus , known from bone finds from the Lower Jurassic of the Connecticut Valley .

There is a similar imbalance in the Jura. There traces of theropods and ornithics ( Grallator , Eubrontes , Amonoepus ) are strongly overrepresented, whereas the ego genus Otozoum , which is predominantly interpreted as “prosauropod”, is underrepresented. Also underrepresented are the rare trace genera Rhynchosauroides and Ameghinichnus, the latter of which is assigned to tritheledontid cynodontics. Again, only one crocodile line archosaur trail, Batrachopus , is roughly as common as the bone material of its potential causer.

The imbalance is explained by the fact that, on the one hand, trace and body fossil societies each represent different tetrapod faunas and that the body fossil societies also do not represent real fauna, but were probably selected and mixed through transport.

A very common invertebrate grave trail is Scoyenia .

Web links

Commons : Newark Supergroup  - collection of images, videos, and audio files

Individual evidence

  1. ↑ a b c d Gwendolyn W. Luttrell: Stratigraphic nomenclature of the Newark Supergroup of eastern North America. US Geological Survey Bulletin 1572. Washington (DC) 1989, online .
  2. ↑ a b c d e f g h i j Robert E. Weems, Lawrence H. Tanner, Spencer G. Lucas: Synthesis and revision of the lithostratigraphic groups and formations in the Upper Permian? –Lower Jurassic Newark Supergroup of eastern North America. Stratigraphy. Vol. 13, No. 2, 2016, pp. 111–153, online (alternative full-text access: ResearchGate ).
  3. ^ A b William Charles Redfield: On the relations of the fossil fishes of the sandstone of Connecticut and other Atlantic states to the Liassic and Oolithic periods. American Journal of Science and Arts, 2nd series. Vol. 22, No. 66, 1856, pp. 357-363, BHL .
  4. ^ A b c Israel C. Russel: Correlation papers: The Newark system. US Geological Survey Bulletin 85. Washington (DC) 1892, online .
  5. ↑ James D. Dana: Manual of Geology - Treating of the Principles of the Science, with Special Reference to American Geological History. 2nd Edition. Ivison, Blakeman, Taylor & Co., New York 1875, archive.org , p. 403 ff .
  6. ↑ Elizabeth M. Truswell: Pre-Cenozoic palynological and continental movements. Pp. 13-26 in: MW McElhinny, DA Valencio (Ed.): Paleoreconstruction of the Continents. Geodynamic Series, Volume 2. American Geophysical Union / Geological Society of America, Washington (DC) / Boulder (CO) 1981, ISBN 0-87590-511-0 , p. 19.
  7. ^ Paul E. Olsen: On the use of the term Newark for Triassic and Early Jurassic rocks of eastern North America. Newsletters on Stratigraphy. Vol. 7, No. 2, 1978, pp. 90-95, doi: 10.1127 / nos / 7/1978/90 .
  8. ^ Albert J. Froelich, Paul E. Olsen: Newark Supergroup, a revision of the Newark Group of eastern North America. Pp. A55-A58 in: Stratigraphic Notes, 1983. US Geological Survey Bulletin 1537-A. Washington (DC) 1984, online .
  9. ↑ a b c d e f g h Martha Oliver Withjack, Roy W. Schlische: A Review of Tectonic Events on the Passive Margin of Eastern North America. Pp. 203-235 in: Paul Post, Donald Olson, Kevin Lyons, Stephen Palmes, Peter Harrison, Norman Rosen (Eds.): 25th Annual Bob F. Perkins Research Conference: Petroleum Systems of Divergent Continental Margin Basins. Society for Sedimentary Geology (SEPM), Gulf Coast Section, Houston (TX) 2005, ResearchGate .
  10. ^ A b c d Robert E. Weems, Paul E. Olsen: Synthesis and revision of groups within the Newark Supergroup, eastern North America. Geological Society of America Bulletin. Vol. 109, No. 2, 1997, pp. 195-209, doi : 10.1130 / 0016-7606 (1997) 109 <0195: SAROGW> 2.3.CO; 2 (alternative full text access : ResearchGate ).
  11. ↑ a b c d e f g h i j k l Warren Manspeizer, Jelle DeBoer, John K. Costain, Albert J. Froelich, Cahit Çoruh, Paul E. Olsen, Gregory J. McHone, John H. Puffer, David C. Prowell: Post-Paleozoic activity. Pp. 319-374 in: Robert D. Hatcher, Jr., William A. Thomas, George W. Many (Eds.): The Geology of North America, Vol F-2: The Appalachian-Ouachita Orogen in the United States. Geological Society of America, Boulder (CO) 1989, ISBN 0-8137-5209-4 .
  12. ^ A b c d Paul E. Olsen: Fossil Great Lakes of the Newark Supergroup - 30 Years Later. Pp. 101-162 in: Alan I. Benimoff (Ed.): Field Trip Guidebook, New York State Geological Association, 82nd Annual Meeting, Staten Island, NY, September 24-26, 2010. ResearchGate .
  13. ^ A b c d Paul E. Olsen: Stratigraphic record of the early Mesozoic breakup of Pangea in the Laurasia-Gondwana Rift System. Annual Review of Earth and Planetary Sciences. Vol. 25, No. 1, 1997, pp. 337-401, doi: 10.1146 / annurev.earth.25.1.337 (alternative full text access : ResearchGate ).
  14. ↑ Andrea Marzoli, Sara Callegaro, Jacopo Dal Corso, Joshua HFL Davies, Massimo Chiaradia, Nassrrdine Youbi, Hervé Bertrand, Laurie Reisberg, Renaud Merle, Fred Jourdan: The Central Atlantic Magmatic Province (CAMP): A Review. P. 91–125 in: Lawrence H. Tanner (Ed.): The Late Triassic World - Earth in a Time of Transition. Topics in Geobiology, Vol. 46. Springer 2018, ISBN 978-3-319-68008-8 .
  15. ↑ a b Newark Supergroup Correlation Chart. Plate 1 (extra supplement) in: Albert J. Froelich, Gilpin R. Robinson, Jr. (Eds.): Studies of the Early Mesozoic Basins of the Eastern United States. US Geological Survey Bulletin 1776. Washington (DC) 1988, online .
  16. ↑ a b c d e f g h i j k l Hans-Dieter Sues, Paul E. Olsen: Stratigraphic and temporal context and faunal diversity of Permian-Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada. Atlantic Geology. Vol. 51, No. 1, 2015, pp. 139–205, doi: 10.4138 / atlgeol.2015.006 (Open Access).
  17. ^ Paul E. Olsen, Dennis V. Kent, Sarah J. Fowell, Roy W. Schlische, Martha O. Withjack, Peter M. LeTourneau: Implications of a comparison of the stratigraphy and depositional environments of the Argana (Morocco) and Fundy ( Nova Scotia, Canada) Permian-Jurassic basins. Pp. 165-183 in: M. Oujidi, M. Et-Touhamin (eds.): Le Permien et le Trias du Maroc. Actes de la Premièr Réunion su Groupe Marocain du Permien et du Trias. Hilal Impression, Oujda 2000, doi: 10.7916 / D86Q26MF .
  18. ^ Heinz W. Kozur, Robert E. Weems: The biostratigraphic importance of conchostracans in the continental Triassic of the northern hemisphere. Pp. 315-417 in Spencer G. Lucas (Ed.): The Triassic Timescale. Geological Society, London, Special Publications, 334. 2010, doi: 10.1144 / SP334.1 , p. 341.
  19. ↑ Nicholas G. McDonald, Peter M. LeTourneau: Paleoenvironmental reconstruction of a fluvial-deltaic-lacustrine sequence, Lower Jurassic Portland Formation, Suffield, Connecticut. Pp. 24-30 in: Albert J. Froelich, Gilpin R. Robinson, Jr. (Eds.): Studies of the Early Mesozoic Basins of the Eastern United States. US Geological Survey Bulletin 1776. Washington (DC) 1988, online , p. 24.
  20. ^ A b Paul E. Olsen, Dennis V. Kent, Bruce Cornet, William K. Witte, Roy W. Schlische: High-resolution stratigraphy of the Newark rift basin (early Mesozoic, eastern North America). Geological Society of America Bulletin. Vol. 108, No. 1, 1996, pp. 40-77, doi : 10.1130 / 0016-7606 (1996) 108 <0040: HRSOTN> 2.3.CO; 2 (alternative full text access : SemanticScholar ).
  21. ^ A b Paul E. Olsen, Dennis V. Kent: Long-period Milankovitch cycles from the Late Triassic and Early Jurassic of eastern North America and their implications for the calibration of the Early Mesozoic time-scale and the long-term behavior of the planets. Philosophical Transactions of the Royal Society of London, A. Vol. 357, No. 1757 (Discussion Meeting Issue 'Astronomical (Milankovitch) calibration of the geological time-scale'), 1999, pp. 1761-1786, doi: 10.1098 / rsta .1999.0400 (alternative full text access : ResearchGate ).
  22. ↑ a b c d e f g h i j k l m n o p q r s t u v Paul E. Olsen: Paleontology and paleoecology of the Newark Supergroup (early Mesozoic, eastern North America). Pp. 185-230 in: Warren Manspeizer (Ed.): Triassic-Jurassic Rifting: Continental Breakup and the Origin of the Atlantic Ocean and Passive Margins. Part A. Developments in Geotectonics 22. Elsevier, Amsterdam / New York 1988, ISBN 0-444-42903-4 .
  23. ^ Eleanora I. Robbins, Gerald P. Wilkes, Daniel A. Textoris: Coal deposits of the Newark rift system. Pp. 649-682 in: Warren Manspeizer (ed.): Triassic-Jurassic Rifting: Continental Breakup and the Origin of the Atlantic Ocean and Passive Margins. Developments in Geotectonics 22. Elsevier, Amsterdam / New York 1988, ISBN 0-444-42903-4 .
  24. ^ Peter W. Weigand, Paul C. Ragland: Geochemistry of Mesozoic dolerite dikes from eastern North America. Contributions to Mineralogy and Petrology. Vol. 29, No. 3, 1970, pp. 195-214, doi: 10.1007 / BF00373305 .
  25. ↑ a b c Richard P. Tollo, David Gottfried: Early Jurassic quartz normative magmatism of the eastern North America province: Evidence for independent magmas and distinct sources. In: Continental Magmatism, Abstracts - International Association of Volcanology and Chemistry of the Earth's Interior, General Assembly, Santa Fe, New Mexico, USA, June 25 - July 1 1989. New Mexico Bureau of Mines and Mineral Resources Bulletin 131. Socorro (NM ) 1989, p. 270, online (complete volume can be downloaded as PDF), HTML version (abstract only).
  26. ^ A b Richard P. Tollo, David Gottfried: Petrochemistry of Jurassic basalt from eight cores, Newark Basin, New Jersey: Implications for the volcanic petrogenesis of the Newark Supergroup. Pp. 233-259 in: John H. Puffer, Paul C. Ragland (Eds.): Eastern North American Mesozoic Magmatism. Geological Society of America Special Paper 268. Boulder (CO) 1992, doi: 10.1130 / SPE268-p233 ; For a brief description of the geology of the basalts of the Newark Basin and the results of the rock-chemical analyzes previously published in connection with this work, see Richard P. Tollo, David P. Hawkins, David Gottfried: Petrographic and geochemical data for Jurassic basalt from eight cores, Newark basin, New Jersey. Open-File Report 90-689. US Geological Survey, US Department of the Interior, Washington (DC) 1990, online .
  27. ↑ Harvey E. Belkin, Daniel F. Fiorito: Geochemical data for Jurassic basalts in the Early Mesozoic Newark Basin, New Jersey: the data of GT Faust. Open-File Report 93-10. US Geological Survey, US Department of the Interior, Washington (DC) 1993, online .
  28. ^ Paul E. Olsen, Emma C. Rainforth: The "Age of Dinosaurs" in the Newark Basin, with Special Reference to the Lower Hudson Valley. Pp. 59-176 in: Alexander E. Gates (Ed.): 2001 New York State Geological Association Fieldtrip Guidebook: Geology of the Lower Hudson Valley. PDF (10.9 MB), p. 61.
  29. ^ A b Paul E. Olsen, Jessica H. Whiteside, Timothy Fedak: Triassic-Jurassic faunal and floral transition in the Fundy Basin, Nova Scotia. North American Paleontological Convention (NAPC) 2005, Halifax, Nova Scotia. Excursion guide, PDF (46.7 MB), p. 32.
  30. ^ Phillip Huber, Spencer G. Lucas, Adrian P. Hunt: Vertebrate biochronology of the Newark Supergroup Triassic, eastern North America. Pp. 179-186 in: Spencer G. Lucas, Michael Morales (Eds.): The Nonmarine Triassic. New Mexico Museum of Natural History and Science Bulletin, 3. Albuquerque 1993 ( online ), p. 180.
  31. ↑ Spencer G. Lucas: Late Triassic Terrestrial Tetrapods: Biostratigraphy, Biochronology and Biotic Events. Pp. 351-405 in: LH Tanner (Ed.): The Late Triassic World. Topics in Geobiology, 46th Springer, 2018, ISBN
  32. ↑ Sterling J. Nesbitt, Randall B. Irmis, William G. Parker: A critical re-evaluation of the Late Triassic dinosaur taxa of North America. Journal of Systematic Palaeontology. Vol. 5, No. 2, 2007, pp. 209-243, doi: 10.1017 / S1477201907002040 , p. 230.
  33. ^ Paul E. Olsen, Dennis V. Kent, Jessica H. Whiteside, Implications of the Newark Supergroup-based astrochronology and geomagnetic polarity time scale (Newark-APTS) for the tempo and mode of the early diversification of the Dinosauria. Earth and Environmental Science Transactions of the Royal Society of Edinburgh. Vol. 101, special no. 3-4 ( Late Triassic Terrestrial Biotas and the Rise of Dinosaurs ), 2011, pp. 201-229, doi: 10.1017 / S1755691011020032 , pp. 221 f.
  34. ^ Adam C. Pritchard, Jacques A. Gauthier, Michael Hanson, Gabriel S. Bever, Bhart-Anjan S. Bhullar: A tiny Triassic saurian from Connecticut and the early evolution of the diapsid feeding apparatus. Nature Communications. Vol. 9, 2018, item no. 1213, doi: 10.1038 / s41467-018-03508-1 (Open Access)
  35. ↑ Torsten M. Scheyer, Stephan NF Spiekman, Hans-Dieter Sues, Martín D. Ezcurra, Richard J. Butler, Marc EH Jones: Colobops : a juvenile rhynchocephalian reptile (Lepidosauromorpha), not a diminutive archosauromorph with an unusually strong bite. Royal Society Open Science. Vol. 7, 2020, item no. 192179, doi: 10.1098 / rsos.192179 (Open Access)
  36. ↑ Bruce Cornet, Paul E. Olsen: Early to Middle Carnian (Triassic) Flora and Fauna of the Richmond and Taylorsville Basins, Virginia and Maryland, USA Virginia Museum of Natural History Guidebook, No. 1. Martinsville (VA), 1990.
  37. ^ Hans-Dieter Sues, Paul E. Olsen, Peter A. Kroehler: Small tetrapods from the Upper Triassic of the Richmond basin (Newark Supergroup), Virginia. Pp. 161–170 in: Nicholas C. Fraser, Hans-Dieter Sues (Ed.): In the shadow of the dinosaurs: Early Mesozoic tetrapods. Cambridge University Press, 1994, ISBN 0-521-45242-2 .
  38. ^ Hans-Dieter Sues: On Microconodon , a Late Triassic cynodont from the Newark Supergroup of eastern North America. Bulletin of the Museum of Comparative Zoology. Vol. 156, No. 1, 2001, pp. 37-48, BHL
  39. ↑ Lindsay E. Zanno, Susan Drymala, Sterling J. Nesbitt, Vincent P. Schneider: Early crocodylomorph increases top tier predator diversity during the rise of dinosaurs. Scientific Reports. Vol. 5, 2015, item no. 9276, doi: 10.1038 / srep09276 (Open Access)
  40. ↑ Jonathan S. Mitchell, Andrew B. Heckert, Hans-Dieter Sues: Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”. Natural sciences. Vol. 97, 2010, pp. 1117–1121, doi: 10.1007 / s00114-010-0729-0 (Open Access)
  41. ^ Hans-Dieter Sues, Rainer R. Schoch: Anatomy and phylogenetic relationships of Calamops paludosus (Temnospondyli, Stereospondyli) from the Triassic of the Newark Basin, Pennsylvania. Journal of Vertebrate Paleontology. Vol. 33, No. 5, 2013, pp. 1061-1070, doi: 10.1080 / 02724634.2013.759120 (alternative full text access: ResearchGate ).
  42. ↑ a b Cynthia M. Liutkus, James S. Beard, Nicholas C. Fraser, PC Ragland: Use of fine-scale stratigraphy and chemostratigraphy to evaluate conditions of deposition and preservation of a Triassic deposit , south-central Virginia. Journal of Paleolimnology. Vol. 44, 2010, pp. 645-666, doi: 10.1007 / s10933-010-9445-1 (Open Access).
  43. ↑ Vladimir A. Blagoderov, David A. Grimaldi, Nicholas C. Fraser: How time flies for flies: diverse Diptera from the Triassic of Virginia and early radiation of the order. American Museum Novitates, 3572. American Museum of Natural History, New York 2007, online , p. 5.
  44. ^ Paul A. Selden, John M. Anderson, Heidi M. Anderson, Nicholas C. Fraser: Fossil araneomorph spiders from the Triassic of South Africa and Virginia. The Journal of Arachnology. Vol. 27, No. 2, 1999, pp. 401-414, JSTOR .
  45. ^ A b Edwin H. Colbert, Paul E. Olsen: A new and unusual aquatic reptile from the Lockatong Formation of New Jersey (Late Triassic, Newark Supergroup). American Museum Novitates, 3334. American Museum of Natural History, New York 2001, online .
  46. ^ Edwin H. Colbert: A phytosaur from North Bergen, New Jersey. American Museum Novitates, 2230. American Museum of Natural History, New York 1965, online .
  47. ^ Adam Douglas Marsh: The Osteology of Sarahsaurus aurifontanalis and Geochemical Observations of the Dinosaurs from the Type Quarry of Sarahsaurus (Kayenta Formation), Coconino County, Arizona. Ms-Thesis, The University of Texas at Austin, 2013, online , p. 18.
  48. ↑ Peter Malcolm Galton: Prosauropod dinosaurs (Reptilia: Saurischia) of North America. Postilla, 169. Peabody Museum of Natural History, New Haven 1976, BHL , p. 4
  49. ↑ a b Arnaud Brignon: The earliest discoveries of articulated fossil fishes (Actinopterygii) in the United States: A historical perspective. American Journal of Science. Vol. 317, No. 2, 2017, pp. 216–250, doi: 10.2475 / 02.2017.03 .
  50. ^ David B. Weishampel: Another look at the dinosaurs of the East Coast of North America. P. 129–168 in: Colectivo Arqueológico-Paleontológico Salense (ed.): Actas de las III Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno. Salas de los Infantes, Burgos 2006, Yumpu , p. 136 f.
  51. ^ Phillip Huber, Nicholas G. McDonald, Paul E. Olsen: Early Jurassic Insects from the Newark Supergroup, Northeastern United States. Pp. 206-223 in: Peter M. LeTourneau, Paul E. Olsen (Eds.): The Great Rift Valleys of Pangea in Eastern North America, Volume 2: Sedimentology, Stratigraphy, and Paleontology. Columbia University Press, New York 2003, ISBN 0-231-12676-X , ResearchGate .