Geological Society of America

T271 Mass Extinctions: Past, Present, and Future? (Posters)

Tuesday, 24 October 2017
9:00 AM - 6:30 PM
Halls 4EF

STABLE AND RADIOGENIC STRONTIUM ISOTOPE (δ88SR, 87SR /86SR) IN SEAWATER ACROSS GUADALUPIAN-LOPINGIAN BOUNDARY (PERMIAN)

Paper number: T271-3
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Tomomi Kani Presenting Author
Faculty of Advanced Science and Technology Division of Natural Science Earth and Environmental Science, Kumamoto
Yukio Isozaki
University of Tokyo, Tokyo
Keiji Misawa
National Institute of Polar Research, Tachikawa
Akira Ishikawa
University of Tokyo, Tokyo
Shigekazu Yoneda
National Museum of Nature and Science, Tsukuba

Abstract

In order to reconstruct the secular change in stable and radiogenic strontium isotope ratios of Permian seawater, we analyzed mid-oceanic paleo-atoll and shelf limestones that span across the Guadlupian-Lopingian boundary; i.e. at the Akasaka section in Japan deposited on a mid-Panthalassan paleo-seamount at 12 degree South, and at the Lianshan section in S. China deposited on a carbonate platform on the equatorial eastern Tethys. Stable strontium isotope ratios (δ⁸⁸Sr) of the Capitanian (late Guadalupian) to Wuchiapingian (early Lopingian) carbonates were measured by TRITON TIMS, by correcting isotope fractionation during mass spectrometry with ⁸⁷Sr-⁸⁴double spike. The newly obtained δ⁸⁸Sr profile of Middle-Late Permian seawater shows an interval of lowδ⁸⁸Sr values throughout the Capitanian, which is followed by a rapid increase across the G-L boundary. This profile is positively correlated with that of ⁸⁷Sr/⁸⁶Sr ratio, suggesting a sharp change in balance between carbonate burial flux and carbonate dissolution flux across the G-L boundary. The Capitanian minimum in seawater ⁸⁷Sr/⁸⁶Sr and the following rapid increase was likely driven by a major change in erosion/weathering of continental crusts probably in relation with global glaciation/deglaciation.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-299456

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