Results 21 to 30 of about 802 (179)
Pathways and mechanisms of Late Ordovician (Katian) faunal migrations of Laurentia and Baltica [PDF]
Estonian Journal of Earth Sciences, 2015 Late Ordovician strata within the Cincinnati Basin record a mass faunal migration event during the C4 and C5 depositional sequences. The geographic source region for the invaders and the paleoceanographic conditions that facilitated dispersal into the ...
Adriane R. Lam, Alycia L. Stigall
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Open Research Europe, 2023 Background The Svalbard Archipelago is commonly believed to have been located at comparable latitude and, possibly, to have been attached to Laurentia in the early Paleozoic (500–420 Ma) based on trilobite assemblage similarities.
Jean-Baptiste P. Koehl
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Ediacaran Doushantuo-type biota discovered in Laurentia [PDF]
Communications Biology, 2020 AbstractThe Ediacaran period (635–541 Ma) was a time of major environmental change, accompanied by a transition from a microbial world to the animal world we know today. Multicellular, macroscopic organisms preserved as casts and molds in Ediacaran siliciclastic rocks are preserved worldwide and provide snapshots of early organismal, including animal ...
Sebastian Willman +5 more
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Scientific Reports, 2021 The cratonic elements of proto-Australia, East Antarctica, and Laurentia constitute the nucleus of the Palaeo-Mesoproterozoic supercontinent Nuna, with the eastern margin of the Mawson Continent (South Australia and East Antarctica) positioned adjacent ...
Dillon A. Brown +3 more
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Journal of Paleontology, 2022 AbstractThe Late Ordovician (late Katian)Tcherskidiumfauna consisted of large- and thick-shelled virgianid pentamerid brachiopods characterized by large and ribbed shells ofTcherskidiumandProconchidiumand usually associated withHolorhynchus,Deloprosopus, andEoconchidium.
Jisuo Jin +3 more
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Geologica Acta, 2007 A substantial, diverse body of evidence has been interpreted as suggesting that the Cuyania terrane of northwestern Argentina, which includes the Argentine Precordillera, rifted from the Ouachita embayment of Laurentia in the Early Cambrian, drifted ...
S. Finney
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The Medicine Hat Block and the Early Paleoproterozoic Assembly of Western Laurentia
Geosciences, 2020 The accretion of the Wyoming, Hearne, and Superior Provinces to form the Archean core of western Laurentia occurred rapidly in the Paleoproterozoic. Missing from Hoffman’s (1988) original rapid aggregation model was the Medicine Hat block (MHB).
Jennifer N. Gifford +2 more
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THE END OF MIDCONTINENT RIFT MAGMATISM AND THE PALEOGEOGRAPHY OF LAURENTIA [PDF]
Geological Society of America Abstracts with Programs, 2016 Paleomagnetism of the North American Midcontinent Rift provides a robust paleogeographic record of Laurentia (cratonic North America) from ca. 1110 to 1070 Ma, revealing rapid equatorward motion of the continent throughout rift magmatism. Existing age and paleomagnetic constraints on the youngest rift volcanic and sedimentary rocks have been ...
Luke M. Fairchild +4 more
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New reticulosan sponges from the middle Cambrian of Sonora, Mexico [PDF]
Acta Palaeontologica Polonica, 2017 A small assemblage of extremely well-preserved fragments of new sponges has been discovered in calcipelites of the middle Cambrian El Mogallón Formation in the Cerro El Mogallón section, near Arivechi in eastern Sonora, Mexico.
Matilde Sylvia Beresi +3 more
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Introduction: Making the Southern Margin of Laurentia [PDF]
Geosphere, 2010 Continental crust is very long-lived but continents themselves are ephemeral. Earth9s inventory of continental crust changes slowly but how this material is partitioned into separate aggregations is always changing. We call these distinct aggregations of buoyant, felsic crust "continents" and now there are 6 of them: North America, South America ...
Robert Stern +2 more
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