Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena
Consistently positive carbon isotopic values were obtained from in situ peloids, ooids, and stromatolitic carbonate within Neoproterozoic glacial successions in northern Namibia, central Australia, and the North American Cordillera. Because positive values continue upward into the immediately overly...
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/carbon-isotopic-composition-of-neoproterozoic-glacial-carbonates-as-a-test-of-paleoceanographic-models-for-snowball-earth-phenomena(aef26a19-90be-4909-b8b8-5fc5db632169).html https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 http://www.scopus.com/inward/record.url?scp=0035681644&partnerID=8YFLogxK |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/aef26a19-90be-4909-b8b8-5fc5db632169 2023-05-15T18:18:32+02:00 Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena Kennedy, MJ Christie-Blick, N Prave, Anthony Robert 2001-12 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/carbon-isotopic-composition-of-neoproterozoic-glacial-carbonates-as-a-test-of-paleoceanographic-models-for-snowball-earth-phenomena(aef26a19-90be-4909-b8b8-5fc5db632169).html https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 http://www.scopus.com/inward/record.url?scp=0035681644&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Kennedy , MJ , Christie-Blick , N & Prave , A R 2001 , ' Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena ' , Geology , vol. 29 , no. 12 , pp. 1135-1138 . https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 Neoproterozoic paleoclimate carbon cycle carbonates glaciation isotopes DELTA-C-13 EXCURSIONS DEATH-VALLEY PRECIPITATION CALIFORNIA EVOLUTION SEAWATER SR article 2001 ftunstandrewcris https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 2021-12-26T14:11:24Z Consistently positive carbon isotopic values were obtained from in situ peloids, ooids, and stromatolitic carbonate within Neoproterozoic glacial successions in northern Namibia, central Australia, and the North American Cordillera. Because positive values continue upward into the immediately overlying postglacial cap carbonates, the negative isotopic excursions widely observed in those carbonate rocks require an explanation that involves a short-term perturbation of the global carbon cycle during deglaciation. The data do not support the ecological consequences of complete coverage of the glacial ocean with sea ice, as predicted in the 1998 snowball Earth hypothesis of P.F. Hoffman et al. In the snowball Earth hypothesis, the postglacial cap carbonates and associated -5 parts per thousand negative carbon isotopic excursions represent the physical record of CO2 transfer from the high-pCO(2) snowball atmosphere (similar to0.12 bar) to the sedimentary reservoir via silicate weathering in the snowball aftermath. Stratigraphic timing constraints on cap carbonates imply weathering rates of similar to 1000 times preglacial levels to be consistent with the hypothesis. The absence of Sr isotopic variation between glacial and postglacial deposits and calculations of maximum weathering rates do not support a post-snowball weathering event as the origin for cap carbonates and associated isotopic excursions. Article in Journal/Newspaper Sea ice University of St Andrews: Research Portal |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Neoproterozoic paleoclimate carbon cycle carbonates glaciation isotopes DELTA-C-13 EXCURSIONS DEATH-VALLEY PRECIPITATION CALIFORNIA EVOLUTION SEAWATER SR |
spellingShingle |
Neoproterozoic paleoclimate carbon cycle carbonates glaciation isotopes DELTA-C-13 EXCURSIONS DEATH-VALLEY PRECIPITATION CALIFORNIA EVOLUTION SEAWATER SR Kennedy, MJ Christie-Blick, N Prave, Anthony Robert Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
topic_facet |
Neoproterozoic paleoclimate carbon cycle carbonates glaciation isotopes DELTA-C-13 EXCURSIONS DEATH-VALLEY PRECIPITATION CALIFORNIA EVOLUTION SEAWATER SR |
description |
Consistently positive carbon isotopic values were obtained from in situ peloids, ooids, and stromatolitic carbonate within Neoproterozoic glacial successions in northern Namibia, central Australia, and the North American Cordillera. Because positive values continue upward into the immediately overlying postglacial cap carbonates, the negative isotopic excursions widely observed in those carbonate rocks require an explanation that involves a short-term perturbation of the global carbon cycle during deglaciation. The data do not support the ecological consequences of complete coverage of the glacial ocean with sea ice, as predicted in the 1998 snowball Earth hypothesis of P.F. Hoffman et al. In the snowball Earth hypothesis, the postglacial cap carbonates and associated -5 parts per thousand negative carbon isotopic excursions represent the physical record of CO2 transfer from the high-pCO(2) snowball atmosphere (similar to0.12 bar) to the sedimentary reservoir via silicate weathering in the snowball aftermath. Stratigraphic timing constraints on cap carbonates imply weathering rates of similar to 1000 times preglacial levels to be consistent with the hypothesis. The absence of Sr isotopic variation between glacial and postglacial deposits and calculations of maximum weathering rates do not support a post-snowball weathering event as the origin for cap carbonates and associated isotopic excursions. |
format |
Article in Journal/Newspaper |
author |
Kennedy, MJ Christie-Blick, N Prave, Anthony Robert |
author_facet |
Kennedy, MJ Christie-Blick, N Prave, Anthony Robert |
author_sort |
Kennedy, MJ |
title |
Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
title_short |
Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
title_full |
Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
title_fullStr |
Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
title_full_unstemmed |
Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena |
title_sort |
carbon isotopic composition of neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball earth phenomena |
publishDate |
2001 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/carbon-isotopic-composition-of-neoproterozoic-glacial-carbonates-as-a-test-of-paleoceanographic-models-for-snowball-earth-phenomena(aef26a19-90be-4909-b8b8-5fc5db632169).html https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 http://www.scopus.com/inward/record.url?scp=0035681644&partnerID=8YFLogxK |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Kennedy , MJ , Christie-Blick , N & Prave , A R 2001 , ' Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for snowball Earth phenomena ' , Geology , vol. 29 , no. 12 , pp. 1135-1138 . https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2 |
_version_ |
1766195149403062272 |