Results 61 to 70 of about 27,145 (212)

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

Terra Nova, EarlyView.
ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito, B. V. Ribeiro, F. Alkmim, A. Deramchi, C. L. Kirkland   +4 more
wiley   +1 more source

Considering a Neoproterozoic Snowball Earth

Science, 1999
P. F. Hoffman et al. and N. Christie-Blick et al. discuss Hoffman et al.'s paper that "developed a modified 'snowball Earth' hypothesis (2) to explain the association of Neoproterozoic low-latitude glaciation with the deposition of 'cap carbonate' rocks bearing highly depleted carbon isotopic values (δ13C ≤ −5‰).
Christie-Blick, Nicholas, Sohl, Linda E., Kennedy, Martin J.   +2 more
openaire   +4 more sources

Detrital-zircon geochronology and provenance of the Ocloyic synorogenic clastic wedge, and Ordovician accretion of the Argentine Precordillera terrane [PDF]

, 2015
The Precordillera terrane in northwestern Argentina is interpreted to be anexotic (Laurentian) continental fragment that was accreted to western Gondwanaduring the Ordovician. One prominent manifestation of the subductionand collision process is a Middle?
Astini, Ricardo Alfredo, McClelland, William C., Mueller, Paul A., Thomas, William A.   +3 more
core   +1 more source

Quantitative and Nuanced Approaches Elucidate Carbon Isotope Records

Geochemistry, Geophysics, Geosystems
Earth scientists have leveraged carbon isotope records to interpret Earth history and establish chronostratigraphic frameworks for decades (e.g., Halverson et al., 2005, https://doi.org/10.1130/b25630.1; Kaufman & Knoll, 1995, https://doi.org/10.1016 ...
Cedric J. Hagen
doaj   +1 more source

MINERALOGY AND ZIRCON AGE OF CARBONATITES OF THE SREDNYAYA ZIMA COMPLEX (EASTERN SAYAN)

Геодинамика и тектонофизика
The Srednyaya Zima alkaline-ultramafic carbonatite complex is located in the Eastern Sayan and is a part of the area of manifestation of Neoproterozoic rare-metal alkaline-carbonatite magmatism along the southern and southeastern margins of the Siberian ...
I. R. Prokopyev, A. G. Doroshkevich, M. D. Varchenko, D. V. Semenova, I. A. Izbrodin, M. N. Kruk   +5 more
doaj   +1 more source

Relics of ophiolite-bearing accretionary wedges in NE Brazil and NW Africa: Connecting threads of western Gondwana´s ocean during Neoproterozoic times

Geosystems and Geoenvironment, 2023
Neoproterozoic breakup of Rodinia resulted in the formation of several oceanic realms between dispersing cratons, which were later consumed during the assembly of Gondwana. In its western portion, the interior orogenic belts of Gondwana formed during the
Lauro Cézar M. de Lira Santos, Fabrício A. Caxito, Merlain H. Bouyo, Sonia Ouadahi, Kawther Araïbia, Geysson A. Lages, Glenda L. Santos, João Paulo A. Pitombeira, Peter A. Cawood   +8 more
doaj   +1 more source

Petrographic and mineralogical characteristics of diagenetic overprinting in Neoproterozoic diamictites from Murchisonfjorden, Nordaustlandet, Svalbard

Mineralogia
The diagenetic processes exhibited by the Neoproterozoic diamictites from Murchisonfjorden (Nordaustlandet, NE Svalbard) are presented. Diamictite samples from the Cryogene Polarisbreen Group - the Petrovbreen Member of the Elbobreen Formation and the ...
Bal Szczepan, Nejbert Krzysztof, Michalski Krzysztof, Domańska-Siuda Justyna, Manby Geoffrey, Hołda-Michalska Aleksandra, Sláma Jiři   +6 more
doaj   +1 more source

Animal survival strategies in Neoproterozoic ice worlds

Global Change Biology, 2022
AbstractThe timing of the first appearance of animals is of crucial importance for understanding the evolution of life on Earth. Although the fossil record places the earliest metazoans at 572–602 Ma, molecular clock studies suggest a far earlier origination, as far back as ~850 Ma. The difference in these dates would place the rise of animal life into
Griffiths, Huw, Whittle, Rowan J., Mitchell, Emily G.   +2 more
openaire   +3 more sources

The laurentian record of neoproterozoic glaciation, tectonism, and eukaryotic evolution in Death Vally, California [PDF]

, 2013
Neoproterozoic strata in Death Valley, California contain eukaryotic microfossils and glacial deposits that have been used to assess the severity of putative Snowball Earth events and the biological response to extreme environmental change.
A. E. Fallick, A. R. Prave, Aitken, ALLISON, Allison, Armin, Bekker, Berney, BOND, Bowring, Brasier, BURCHFIEL, CLOUD, Cohen, Colpron, CORSETTI, Corsetti, Corsetti, D. Trotzuk, Dalziel, Dalziel, E. F. Smith, Erwin, F. A. Macdonald, F. Waechter, Fanning, FLECK, Goodge, Gutstadt, HOFFMAN, Hoffman, Hoffmann, James, K. Oates, Karlstrom, Kaufman, Kenny, Knauth, Labotka, Licari, Love, Lund, Macdonald, Macdonald, MILLER, Moores, NOBLE, Prave, R. Petterson, S. B. Pruss, Sears, SNOW, Snow, Snow, Timmons, Tucker, Vorob'eva, Walker, WERNICKE, Wright, WRIGHT, Yin, Zhou   +62 more
core   +1 more source

Neoproterozoic subduction along the Ailaoshan zone, South China : geochronological and geochemical evidence from amphibolite [PDF]

, 2014
This study was supported by China Natural Science Foundation (41190073 and 41372198), National Basic Research Program of China (2014CB440901) and Natural Environment Research Council (grant NE/J021822/1).Lenses of amphibolites occur along the Ailaoshan ...
Cai, Yongfeng, Cawood, Peter A., Fan, Weiming, Liu, Huichuan, Wang, Yuejun, Xing, Xiaowan, Zhang, Yuzhi   +6 more
core   +1 more source