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Neoproterozoic granitoids on Wrangel Island
Doklady Earth Sciences, 2016Based on geochronological U–Pb studies, the age of Wrangel Island granitoids was estimated as Neoproterozoic (Cryogenian). Some granitoids contain zircons with inherited cores with an estimated age of 1010, 1170, 1200, and >2600 Ma, assuming the presence of ancient (Neoarchean–Mesoproterozoic) rocks in the Wrangel Island foundation and their ...
M. V. Luchitskaya +3 more
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The Neoproterozoic glacial broom
GeologyAbstract Neoproterozoic snowball Earth events reflect globally frigid conditions thought to have stimulated changes in geochemical cycling with planetary biotic response. We investigated the impact of these events on sediment dynamics, focusing on the detrital zircon record within the Dalradian Supergroup of Scotland and Ireland ...
C.L. Kirkland +3 more
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The Neoproterozoic supercontinent Palaeopangaea
Gondwana Research, 2007Abstract The Rodinia hypothesis for the Neoproterozoic Supercontinent reconstruction is associated with five major problems: (i) The palaeomagnetic test requires continental break-up hundreds of millions of years before the geological evidence for this event is recognised near the dawn of the Cambrian.
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Two or four Neoproterozoic glaciations?
Geology, 1998A thick Neoproterozoic carbonate and glaciogenic succession of the southern Congo craton has yielded δ 13 C and 87 Sr/ 86 Sr records through the later Cryogenian (ca. 750–600 Ma) and earlier part of the Terminal Proterozoic (ca. 600–570 Ma). Sizeable negative δ 13 C excursions (to less than–5‰) occur above each of two glacial intervals and the 87 Sr/
Martin J. Kennedy +4 more
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Neoproterozoic banded iron formations
Lithology and Mineral Resources, 2009Two epochs of the formation of ferruginous quartzites—Archean-Paleoproterozoic (3.2–1.8 Ga) and Neoproterozoic (0.85–0.7 Ga)—are distinguished in the Precambrian. They are incommensurable in scale: the Paleoproterozoic Kursk Group of the Kursk Magnetic Anomaly (KMA) extends over 1500 km, whereas the extension of Neoproterozoic banded iron formations ...
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Neoproterozoic Laurentia-Australia fit
Geology, 1993The proposed Vendian juxtaposition of western North America and eastern Australia can be tested by comparing sequences on each margin that developed during the major glacial epochs of the Neoproterozoic. The actual fitting of the margins, however, is more difficult, because both margins have been deformed since separation.
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Neoproterozoic timescales and stratigraphy
Geological Society, London, Special Publications, 2009Abstract The Infracambrian is a term for mostly Neoproterozoic successions in North Africa and areas to the east. Its base lies within the middle Neoproterozoic period, or Cryogenian, includes the youngest Neoproterozoic period, or Ediacaran, and continues into the early Cambrian to the level at which trilobites first appear.
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Toward a Neoproterozoic composite carbon-isotope record
Geological Society of America Bulletin, 2005Glacial deposits of Sturtian and Marinoan age occur in the well-studied Neoproterozoic successions of northern Namibia, South Australia, and northwestern Canada. In all three regions, the Marinoan glaciation is presaged by a large negative δ 13 C anomaly, and the cap carbonates to both glacial units share a suite of unique sedimentological ...
Halverson, G. +4 more
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Neoproterozoic Acritarch Biostratigraphy of China
2020According to studies of the acritarch biostratigraphy in China, the evolution of Neoproterozoic acritarchs roughly involves four stages, from older to younger, including the pre-Doushantuo Stage, the Doushantuo Stage, the Denying Stage and the Meishucun Stage.
Yin Leiming, Yin Chongyu
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