Revised Wonoka isotopic anomaly in South Australia and Late Ediacaran mass extinction
The global Late Ediacaran Shuram–Wonoka carbon isotope anomaly has been regarded as the largest and longest known isotopic anomaly in the ocean, assuming that all Ediacaran carbonate is marine. Disregarding carbonate in South Australia shown here to be palaeosol or palaeokarst, the synchronous marine organic–carbonate excursion is only −8‰ for δ13C organic and −6‰ for δ13C carbonate, and lasted less than a million years. This revised magnitude and duration is comparable with perturbations across the Permian–Triassic boundary, and correlative with a global Late Ediacaran acritarch mass extinction. Like Permian–Triassic isotopic excursions, the revised organic–carbonate Wonoka excursion may also have been a greenhouse palaeoclimatic warm spike, which terminated valley incision and glacioeustatic drawdown during the mid-Ediacaran Fauquier Glaciation, and preceded chill of the Late Ediacaran Billy Springs Glaciation.
Citation Information
Publication Year | 2014 |
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Title | Revised Wonoka isotopic anomaly in South Australia and Late Ediacaran mass extinction |
DOI | 10.1144/jgs2014-016 |
Authors | Gregory J. Retallack, André Marconato, Jeffery T. Osterhout, Kathryn E. Watts, Ilya N. Bindeman |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of the Geological Society |
Index ID | 70206601 |
Record Source | USGS Publications Warehouse |
USGS Organization | Geology, Minerals, Energy, and Geophysics Science Center |