T58 The Ediacaran-Cambrian Ecosphere (R)evolution: Emerging Records from Central and East Asia (Posters)
Sunday, 19 October 2014
9:00 AM - 5:00 PM
Exhibition Hall C
OCEANIC OXIDATION MECHANISMS SPANNING THE SNOWBALL EARTH AND EARLY ANIMAL DIVERSIFICATION
Paper number: T58-1
Program: Technical Sessions
Time: 9:00 AM – 5:00 PM
Authors
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Atena ShizuyaTohoku University, Sendai, N/A
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Kenji YamadaTohoku University, Sendai, N/A
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Masahiro ObaTohoku University, Sendai
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Minori KikuchiTohoku University, Sendai, N/A
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Naoto SenbaTohoku University, Sendai, N/A
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Zhong Qiang ChenChina University of Geosciences, Wuhan
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Jinnan TongChina University of Geosciences, Wuhan
Abstract
The late Neoproterozoic (780 million years ago (Ma)) to early Cambrian (520 Ma) interval witnessed the rise and evolution of early animals from sponges to vertebrates. Oceanic oxidation is believed to occur just after the Gaskiers Glaciation (580 Ma), partial glaciation, to explain appearance of the Ediacaran biota. We investigated a redox proxy of sedimentary organic molecules during 850 to 520 Ma. Those data indicate that significant oxidation in shallow intermediate waters occurred just after the Sturtian global Glaciation (730-720 Ma) and the Marinoan global Glaciation (650-635 Ma), and oxidation in the deep water occurred in early Cambrian. This indicates that strong linkage between the global glaciation so called Snowball Earth and oceanic oxidation due to an increase in atmospheric oxygen. Moreover, those data show anoxic or suboxic conditions in surface waters during the Marinoan global Glaciation and Ediacaran-Cambrian transition.