Results 131 to 140 of about 254 (156)
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Circular, Cryogenic Structures from the Hirnantian Deglaciation Sequence (Anti-Atlas, Morocco)
Journal of Sedimentary Research, 2013Abstract More than a hundred circular structures are observed at the topmost part of the Late Ordovician glaciogenic record in the central Anti-Atlas, southern Morocco. The structures were formed in the outer glaciated platform and characterize the Hirnantian deglaciation sequence.
Nutz, Alexis +2 more
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A global synthesis of the latest Ordovician Hirnantian brachiopod faunas
Transactions of the Royal Society of Edinburgh: Earth Sciences, 1988ABSTRACTA global review of new and existing data on the distribution of uppermost Ordovician (Hirnantian) brachiopods indicates the existence of at least three biogeographically distinct faunas. The typical Hirnantia fauna characterised subtropical and temperate latitudes and comprised a variety of ecological associations; the fauna reached its acme ...
Rong Jia-yu, David A. T. Harper
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Taphonomy of exceptional sponge preservation in the Hirnantian Anji Biota, China
Journal of the Geological Society, 2022The Anji Biota is a unique deposit with exceptionally preserved sponges and other organisms in deep-water, uppermost Ordovician mudstone of Zhejiang Province, China. The sponge fossils preserve remarkable details including carbonaceous preservation of soft tissues and axial filaments of spicules, but the taphonomy of the deposit has not previously been
Xuejin Wu +4 more
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Late Hirnantian Clastic Depositional Systems Using Sequence Stratigraphy and Chronostratigraphy
Abu Dhabi International Petroleum Exhibition & Conference, 2018Abstract The Hoban and Baqaa Members are located between the glacial to early post-glacial Sarah Formation (Ordovician) and the Qalibah Formation (Silurian). They have been distinguished as separate stratigraphic units in few outcrops of northern Saudi Arabia based on palynological analyses, graptolites, shell fragments, and their ...
Saeed Alshahrani, Rainer Zuhlke
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Pre‐Hirnantian Ashgill climatically warm event in the Mediterranean region
Lethaia, 2003Compilation of the marine, benthic megafossils from approximately the mid-Ashgill of the Mediterranean region, including much of Central and Southern Europe plus North Africa, and elsewhere indicates a warm interval featuring bioclastic limestone and a warm climate marine fauna.
A.J Boucot +3 more
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Brachiopods from the Hirnantian Stage (Ordovician–Silurian) at Percé, Quebec
1976(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
Lespérance, Pierre Jacques +1 more
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Geological Society of America Abstracts with Programs, 2017
The so-called Big Five mass extinctions of the Phanerozoic include two prominentPalaeozoic episodes: the end-Ordovician and end-Permian events, both with large biodiversityloss. We consider that the end-Ordovician (Hirnantian) extinction could bebest compared to the Middle Permian end-Guadalupian (=Capitanian) extinction,rather than to the end-Permian (
Isozaki, Yukio, Servais, Thomas
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The so-called Big Five mass extinctions of the Phanerozoic include two prominentPalaeozoic episodes: the end-Ordovician and end-Permian events, both with large biodiversityloss. We consider that the end-Ordovician (Hirnantian) extinction could bebest compared to the Middle Permian end-Guadalupian (=Capitanian) extinction,rather than to the end-Permian (
Isozaki, Yukio, Servais, Thomas
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Environmental changes in the Hirnantian (upper Ordovician) of the Prague Basin, Czechoslovakia
Geological Journal, 1989AbstractSedimentary sequences through the uppermost Ordovician (Hirnantian), Kosov Formation, are described. The Kosov Formation is a shale‐dominated formation with two thin horizons of sandy diamictites near the base and two ‘flysch’ units separated by shales forming the main part of the formation, which is overlain abruptly by Silurian graptolitic ...
P. J. Brenchley, P. Štorch
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The Hirnantian δ13C Positive Excursion in the Nabiullino Section (South Urals)
Doklady Earth Sciences, 2018The upper Sandbian, Katian, and Hirnantian complexes of conodonts in the upper Ordovician section of the western slope of the Southern Urals near the village of Nabiullino were studied. The δ13C positive excursion with a maximum of 3.3‰ associated with the global Hirnantian isotopic event, HICE, was fixed for the first time.
R. R. Yakupov +2 more
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Chemical Geology, 2010
Abstract We examined the Sr-isotopic composition of one species of well-preserved brachiopod species from the mid-Cincinnatian (Upper Katian–Lower Hirnantian, Upper Ordovician) in closely spaced samples from one borehole on the western shelf of the Upper Ordovician Appalachian low latitude retroarc basin in southwestern Ontario. The section spans the
R. Hannigan, M.E. Brookfield, A.R. Basu
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Abstract We examined the Sr-isotopic composition of one species of well-preserved brachiopod species from the mid-Cincinnatian (Upper Katian–Lower Hirnantian, Upper Ordovician) in closely spaced samples from one borehole on the western shelf of the Upper Ordovician Appalachian low latitude retroarc basin in southwestern Ontario. The section spans the
R. Hannigan, M.E. Brookfield, A.R. Basu
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