Results 251 to 260 of about 8,265,842 (328)

The Absaroka Sequence: Lower Pennsylvanian—Lower Jurassic

1987
The Absaroka Sequence was deposited through the longest of Phanerozoic geological intervals to be considered in this book. It took more than three geological periods (Pennsylvanian through Early Jurassic time) for the complete sequence to be laid down and, during these roughly 145 Myr., some fundamental changes occurred on Earth and on the continent ...
William J. Frazier, David R. Schwimmer
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Synthesis and revision of the lithostratigraphic groups and formations in the Upper Permian?-Lower Jurassic Newark Supergroup of eastern North America

Stratigraphy, 2016
The Upper Permian? - Lower Jurassic Newark Supergroup of eastern North America has a strikingly uniform succession of lithologic units. This uniformity is seen regardless of whether these units are characterized on the basis of their lithostratigraphy ...
R. Weems, L. Tanner, S. Lucas
semanticscholar   +1 more source

Magnetostratigraphy of the Jurassic Through Lower Cretaceous in the Neuquén Basin

2020
The first magnetostratigraphic scales for the Jurassic through Early Cretaceous from the Southern Hemisphere have been constructed over the last decades from marine sections in the Neuquen Basin. Paleomagnetic sites were tied to ammonite zones in order to achieve well-refined ages of studied sections. Diverse field tests for the paleomagnetic stability
Iglesia Llanos, Maria Paula, Kietzmann, Diego Alejandro   +1 more
openaire   +2 more sources

The lower jurassic of the north viking graben in the context of western european lower jurassic stratigraphy

1995
The Lower Jurassic interval of the North Viking Graben (60-62°N) has been divided into four regressive-transgressive cycles based upon the wireline log correlation of some 80 wells, largely from the Norwegian Continental Shelf, supplemented by biostratigraphic data.
openaire   +1 more source

Lower Jurassic palynostratigraphy of Eastern Siberia

Stratigraphy and Geological Correlation, 2017
This paper presents the results of a palynological study of the natural outcrops of the Lower and Middle Jurassic on the Kelimyar River (Outcrops 5, 6, 7, 14, and 16) and two boreholes, Middle-Nakynskaya and Ygyata-Tyungskaya 1, in Eastern Siberia. The Ukugut, Tyung, Motorchuna, Suntar, Kyrin, and Kelimyar formations were studied.
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Jurassic faunas of the Canadian Arctic, Lower Jurassic and lowermost Middle Jurassic ammonites

1960
Lower Jurassic and lower Bajocian faunas are widely distributed in the Canadian Arctic, particularly in the Arctic Archipelago, where marine lower Sinemurian, Toarcian, and Bajocian are represented. In the Aklavik Range (northeastern Richardson Mountains, Arctic Coast region) lower and upper Sinemurian rocks are present; farther to the west lower ...
openaire   +1 more source

Reappraisal of the gastric contents of a Lower Jurassic ichthyosaur

Geological Curator, 2010
Re-examination of cephalopod hooklets preserved within the gastric mass of several Lower Jurassic ichthyosaurs reveals that these reptiles fed mainly on phragmoteuthids, rather than belemnites as previously proposed. This conclusion matches the findings of recent research on ichthyosaurs and well-preserved coleoids from the Lower Jurassic (Toarcian ...
David E. Valente, Amanda L. Edwards, John E. Pollard   +2 more
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Metacopine ostracods in the Lower Jurassic

1982
The present state of knowledge of metacopine ostracods in the Jurassic is reviewed and their biostratigraphic significance analysed. Particular attention is paid to the disappearance of this group near the Pliensbachian/Toarcian boundary, which is an important but poorly known extinction event in the history of the Ostracoda.
openaire   +1 more source

The Lower Lias (Lower Jurassic) of the Bridgend area, South Wales

Proceedings of the Geologists' Association, 1986
The Lias in the Bridgend area reveals a facies of marly limestones and clays in the off-shore Lias and a new locality in the marginal Lias which equates with the Brocastle Beds of Moore (1867) . Re-examination of the marginal Lias along the coast between Ogmore-by-Sea and Southerndown casts doubt on Tawney's (1866) division of these deposits into ...
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Ornithopod dinosaur tracks from the Lower Jurassic of Queensland

Alcheringa: An Australasian Journal of Palaeontology, 1994
Natural casts of seven small footprints have been identified on a single weathered block derived from the Precipice Sandstone (Lower Jurassic) of the Carnarvon Gorge, southeastern Queensland. The footprints are attributed to omithopod dinosaurs and are referred to the ichnogenus Anomoepus.
openaire   +3 more sources