scholarly journals Dinoflagellate cysts from the Upper Triassic (Norian) of northeastern Iran

2008 ◽  
Vol 27 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Ebrahim Ghasemi-Nejad ◽  
Martin J. Head ◽  
Maryam Zamani
Keyword(s):  
World Wide ◽  
Sedimentary Facies ◽  
Upper Triassic ◽  
Late Triassic ◽  
Dinoflagellate Cysts ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Northwest Europe ◽  
Near Shore ◽  
Early Late

Abstract. Upper Triassic (Norian) strata of the Miankuhi Formation in northeastern Iran have been studied palynologically, revealing a diverse but poorly preserved association of dinoflagellate cysts. Based on representatives of the genera Hebecysta, Heibergella, Rhaetogonyaulax and Sverdrupiella, the strata are assigned to the middle of the Hebecysta balmei Zone with an inferred age of early Late Norian. The association shows similarities with assemblages from Australia, New Zealand, Indonesia, Northwest Europe, arctic Canada and Alaska, indicating an interconnection of warm Tethyan waters during the Late Triassic. The occurrence of Sverdrupiella species in the clastic, near-shore marine deposits of Miankuhi, and their presence in similar sedimentary facies world-wide, indicate that this genus was well adapted to clastic shallow-marine environments.

scholarly journals A review of Palaeozoic and Mesozoic tetrapods from Greenland

2018 ◽  
Vol 66 ◽  
pp. 21-46 ◽  
Author(s):  
Marco Marzola ◽  
Octávio Mateus ◽  
Jesper Milàn ◽  
Lars B. Clemmensen
Keyword(s):  
Late Jurassic ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Late Triassic ◽  
Late Devonian ◽  
Early Triassic ◽  
Shallow Marine ◽  
East Greenland ◽  
Marine Deposits ◽  
Theropod Dinosaurs

This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

The stratigraphy of the Nicola Group in the Hedley district, British Columbia, and the chemistry of its intrusions and Au skarns

1996 ◽  
Vol 33 (8) ◽  
pp. 1105-1126 ◽  
Author(s):  
G. E. Ray ◽  
I. C. L. Webster ◽  
G. L. Dawson
Keyword(s):  
British Columbia ◽  
Oxidation State ◽  
Sedimentary Facies ◽  
Island Arc ◽  
Quartz Diorite ◽  
Late Triassic ◽  
Nickel Plate ◽  
Shallow Marine ◽  
Tectonically Active ◽  
Volcaniclastic Rocks

The Nicola Group at Hedley, British Columbia, is a late Carnian to late Norian (Late Triassic) sequence of calcareous sedimentary and arc-related volcaniclastic rocks. It was deposited on a tectonically active paleoslope that marked either the rifted eastern margin of the shallow-marine Nicola basin or the faulted edge of an intrabasinal platform. The lower part of the Nicola Group comprises a succession of four essentially coeval sedimentary facies. From east to west across the district, these are informally named the thin (approx. 200 m), shallow-marine, limestone-dominant French Mine formation; the thicker, calcareous siltstone-dominant Hedley and Chuchuwayha formations in the central part of the district; and the thick (up to 2200 m), deeper water and argillite-dominant Stemwinder formation. These facies are all blanketed by the Whistle formation, a 1200 m thick unit of basaltic tuff and tuffaceous sediment whose base is marked by a gravity-slide megabreccia, the Copperfield breccia. The Nicola arc at Hedley was associated with two plutonic episodes. Oldest are the Hedley intrusions, which are related to economic Au skarns, including the Nickel Plate deposit, which has produced over 71 t of gold from 13.4 Mt of ore. The Hedley intrusions are similar in composition (quartz gabbro to quartz diorite) and overall metaluminous chemistry to other island-arc-generated plutons related to many Cu and Fe skarns in British Columbia, although they are less evolved. They also differ in having lower Fe2O3/FeO ratios (avg. 0.23), indicating a reduced oxidation state, and higher Ba/La and Sc/Nb ratios. A slightly younger plutonic episode produced the 193 Ma (Early Jurassic) Bromley batholith and the 194 Ma Mount Riordan stock; the latter is associated with the Mount Riordan (Crystal Peak) industrial garnet skarn. Gold skarns are preferentially developed in areas where the Hedley intrusions cut the Hedley and French Mine formations. The Au skarn ore is marked by anomalous As, Bi, Te, and Co values, and by high pyrrhotite/pyrite and pyroxene/garnet ratios. It is distinct from the ore of Fe, Cu, Mo, Pb–Zn, W, and Sn skarns by its very low Cu/Au, Zn/Au, and Ag/Au ratios (avg. 97, 18, and 12, respectively).

scholarly journals Early Cretaceous (Neocomian-Cenomanian) Palynomorphs

1985 ◽  
Vol 4 (1) ◽  
pp. 131-149 ◽  
Author(s):  
B. Thusu ◽  
J. G. L. A. Van Der Eem
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Age Determination ◽  
Marine Environments ◽  
Dinoflagellate Cysts ◽  
Shallow Marine ◽  
The North ◽  
Close Proximity ◽  
Pollen And Spores ◽  
Early Late

Abstract. INTRODUCTIONThis study is primarily concerned with the Neocomian to Aptian palynomorphs recorded in selected exploration wells (See Fig. 9). In order to document a complete Early Cretaceous microfloral succession in the studied wells, a reconnaissance of Aptian to Early Cenomanian palynomorphs was also undertaken. Details of the results from this younger interval appear in a later section.Palynomorph assemblages vary in preservation and character. To the north, sandstone, siltstone and shale deposited in shallow-marine environments, contain well-preserved assemblages of dinoflagellate cysts, pollen and spores which can be used for stage-level age determination. A majority of the samples analysed, however, contain moderate numbers of dinoflagellate cysts, but fewer miospores. The abundance of land derived detritus indicates the relatively close proximity of the shoreline. In the central and southern parts of the study area, sandstone and siltstone that are deposited in non-marine, fluvial, lacustrine or lagoonal environments show a general paucity of well-preserved palynofloras. Miospores of stratigraphic value are generally rare or absent although the majority of the samples are dominated by land derived detritus.PALYNOMORPH SUCCESSIONThe majority of the wells from northern Cyrenaica show a hiatus at the Jurassic Cretaceous boundary. Late Neocomian or Aptian sediments occur immediately above Middle or early Late Jurassic sediments. Well preserved Neocomian palynomorphs were recorded in wells A1-36, B1-36, Bla-18 and A1-45. The stratigraphical ranges of palynomorphs presented on the plate explanations are local ranges and are based on the studied intervals only. A preliminary palynological zonation of Late Jurassic (Late Kimmeridgian) to . . .

scholarly journals Non-dinosaurian dinosauromorphs from the Chinle Formation (Upper Triassic) of the Eagle Basin, northern Colorado: Dromomeron romeri (Lagerpetidae) and a new taxon, Kwanasaurus williamparkeri (Silesauridae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7551 ◽  
Author(s):  
Jeffrey W. Martz ◽  
Bryan J. Small
Keyword(s):  
Articular Surface ◽  
Upper Triassic ◽  
Late Triassic ◽  
New Taxon ◽  
Dietary Specialization ◽  
Sister Clade ◽  
Chinle Formation ◽  
Northern Colorado ◽  
Land Vertebrate ◽  
Early Late

The “red siltstone” member of the Upper Triassic Chinle Formation in the Eagle Basin of Colorado contains a diverse assemblage of dinosauromorphs falling outside of Dinosauria. This assemblage is the northernmost known occurrence of non-dinosaurian dinosauromorphs in North America, and probably falls within the Revueltian land vertebrate estimated biochronozone (215–207 Ma, middle to late Norian). Lagerpetids are represented by proximal femora and a humerus referable to Dromomeron romeri. Silesaurids (non-dinosaurian dinosauriforms) are the most commonly recovered dinosauromorph elements, consisting of dentaries, maxillae, isolated teeth, humeri, illia, femora, and possibly a scapula and tibiae. These elements represent a new silesaurid, Kwanasaurus williamparkeri, gen. et sp. nov., which possesses several autapomorphies: a short, very robust maxilla with a broad ascending process, a massive ventromedial process, a complex articular surface for the lacrimal and jugal, and 12 teeth; 14 dentary teeth; an ilium with an elongate and blade-like preacetabular process and concave acetabular margin; a femur with an extremely thin medial distal condyle and a depression on the distal end anterior to the crista tibiofibularis. The recognition of K. williamparkeri further demonstrates the predominantly Late Triassic diversity and widespread geographic distribution across Pangea of the sister clade to Asilisaurus, here named Sulcimentisauria. Silesaurid dentition suggests a variety of dietary specializations from faunivory and omnivory in the Middle Triassic and early Late Triassic (Carnian), to herbivory in the Late Triassic (Carnian and Norian), with the latter specialization possibly coinciding with the radiation of Sulcimentisauria across Pangea. The extremely robust maxilla and folidont teeth of K. williamparkei may represent a strong herbivorous dietary specialization among silesaurids.

scholarly journals The Upper Triassic - Lower Jurassic Vinding and Gassum Formations of the Norwegian-Danish Basin

1978 ◽  
Vol 3 ◽  
pp. 1-26
Author(s):  
Finn Bertelsen
Keyword(s):  
Lower Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
North German Basin ◽  
Sea Level Changes ◽  
Northern Margin ◽  
The North ◽  
Tectonic Events ◽  
Near Shore ◽  
German Basin

The late Triassic-early Jurassic Vinding and Gassum Formations are redefined and mapped within the Norwegian-Danish Basin. The Vinding Formation is a brackish marine shallow water deposit restricted to the Danish Subbasin. It is of late Norian-Rhaetian age. The Gassum Formation is a fluvio-deltaic to near-shore marine, arenaceous deposit carried from north and east into the basin. Its upper part is diachronous, ranging in age from Rhaetian in the basin center to late Sinemurian in the northern margin. It is proposed that the Ullerslev Formation is repealed. The parallelism between the course of sedimentation in the Norwegian-Danish Basin, the North German Basin and the Polish Basin indicates eustatic sea level changes to be of greater importance than local tectonic events.

scholarly journals An enigmatic Arthropoda from the Upper Triassic (Carnian) southwestern Gondwana (Argentina)

2019 ◽  
Vol 94 (2) ◽  
pp. 279-290 ◽  
Author(s):  
María B. Lara ◽  
Bárbara Cariglino ◽  
Ana M. Zavattieri ◽  
Iracema Zacarías
Keyword(s):  
New Genus ◽  
Upper Triassic ◽  
Late Triassic ◽  
New Taxon ◽  
Delta Plain ◽  
Ecological Implications ◽  
Fish Remains ◽  
Potrerillos Formation ◽  
Warm Temperate ◽  
Early Late

AbstractThe presence of a new taxon, Duraznovis gallegoi new genus new species is reported and described from an early Late Triassic (Carnian) deposit in Argentina. Two specimens, recovered from the Quebrada del Durazno locality, uppermost levels of the Potrerillos Formation, Cuyana Basin (Mendoza), are represented by the molds of their shield and imprints of soft parts. The identity of these specimens appears enigmatic but closely resembles in the possession of a generalized arthropod morphology and a distinctive combination of characters, to living and fossil representatives of xiphosurans (Chelicerata) and notostracans (Branchiopoda). The new fossils are associated with a rich biota comprising abundant insects, spinicaudatans, plants, and scarce fish remains living in semipermanent swamps and/or ponds within a delta plain environment with intermittent episodes of flooding, in a warm temperate and humid megamonsoonal climate during Triassic times. In this context, we analyze the taphonomic and ecological implications of their presence. Lastly, these unique specimens at the Quebrada del Durazno locality adds to the diversity of the biota, revealing the importance of this site as an exceptional paleontological Triassic deposit.UUID: http://zoobank.org/8d1194c2-170c-4b7a-b0c6-5c08b0974d95

scholarly journals Glauconitic deposits at Julegård on the south coast of Bornholm, Denmark dated to the Cambrian

2011 ◽  
Vol 59 ◽  
pp. 1-12
Author(s):  
Lars B. Clemmensen ◽  
Richard G. Bromley ◽  
Paul Martin Holm
Keyword(s):  
Lower Cambrian ◽  
Trace Fossils ◽  
Upper Triassic ◽  
South Coast ◽  
The South ◽  
Shallow Marine ◽  
Marine Deposits

Bioturbated, glauconitic siltstones and sandstones are overlain by presumed Upper Triassic deposits at coastal exposures at Julegård on the south coast of Bornholm. These glauconitic deposits have not previously been dated. A 40Ar-39Ar dating of the glaucony gives an age of 493 ± 2 Ma suggesting the deposits belong to the Lower Cambrian Norretorp Member of the Læså Formation. The shallow marine deposits are strongly bioturbated, but only a single ichnoassociation is represented. The ichnogenus is referable to either Trichophycus Miller and Dyer, 1878 or Teichichnus Seilacher, 1955. Rare examples of Rusophycus Hall, 1852, probably trilobite trace fossils, are also represented.

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