261 D6. Recent Advances in Geochemistry (Posters)

Wednesday, 25 September 2019
9:00 AM - 6:30 PM
Hall AB, North Building

GLOBAL OCEAN ACIDIFICATION DURING THE LATE PERMIAN- LATE TRIASSIC AS INFERRED FROM CARBONATE CALCIUM ISOTOPE

Paper number: 261-8
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

  • Feihong Ye Presenting Author
    China University of Geosciences,, WUHAN
  • Laishi Zhao
    China University of Geosciences,, WUHAN
  • Ying Cui
    Montclair State University: Department of Earth and Environmental Studies, Montclair, NJ
  • Lei Zhang
    State Key Laboratory of Geological Processes and Mineral Resources, Wuhan

Abstract

The end-Permian mass extinction (EPE; ca. 251.9 Ma) is the largest biological disaster in the Phanerozoic and has been hypothesized to be caused by ocean acidification due to large amount of CO2 (>10,000 Pg C) emitted through Siberian Traps volcanism. The marine ecosystem, however, did not recover until several million years after the EPE. The continued deterioration of the environment is suggested to be responsible for the delayed recovery of life. To understand the causes and consequence of the end-Permian extinction event, we performed detailed geochemical analysis (δ44/40Ca, δ13C, 87Sr/86Sr and trace elements) on carbonate from the Kamura section in Japan. The Kamura section analyzed spans the Uppermost Permian and Upper Triassic, deposited as shallow water successions in a seamount in the central Panthalassic ocean. The age framework of the Kamura section was determined based on conodont zonation, carbonate carbon isotope stratigraphy and age model. Both δ44/40Ca and δ13Ccarb exhibit negative excursions across the PTB, exhibiting closely coupled relationship. We suggest that CO2-driven global ocean acidification best explains the coincidence of the negative excursions in both δ44/40Ca and δ13Ccarb. During the Middle and Late Triassic, strong coupling between δ44/40Cacarb and δ13Ccarb is collapsed, suggesting a recovery to normal marine pH. 87Sr/86Sr suggest the Siberian Trap volcanism played a significant role on the δ44/40Ca records during the Early Triassic. The evidence of the ocean acidification from the Panthalassic ocean gives us a new sight into the magnitude of the mass extinction.

Geological Society of America Abstracts with Programs. Vol. 51, No. 5

doi: 10.1130/abs/2019AM-339378

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