T335 Marine and Terrestrial Records of Extreme Climates and Extinction: Making Sense of Similarities and Differences (Posters)

Wednesday, 28 September 2016
9:00 AM - 6:30 PM
Exhibit Hall E/F

MATGROUND OASIS FACILITATING RAPID BIOTIC RECOVERY FOLLOWING THE END-PERMIAN EXTINCTION IN MARINE HABITABLE ZONE

Paper number: T335-3
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Marine ecosystems experienced the most profound recovery following the Permian‒Triassic (P‒Tr) mass extinction during their Phanerozoic evolutionary history. Biotic recovery, however, occasionally occurred fast in some cases. For instance, trace-making organisms may recover faster in shallow marine habitable zone than in other settings, and also rebound faster in relatively higher latitudes than in low latitudes. Here, we present a new case that trace-makers recovered rapidly following the P‒Tr biocrisis in matground oasis of shallow marine habitable zone based on an anomalously diverse and high-tiering trace-fossil assemblage from the lowest Triassic sandstones in the southern Qilian basin of Qinghai Province, western China. The studied area was situated at the northern margins of the Paleotethys Ocean and located at moderate-high latitudes during the P‒Tr transition. The lowest Triassic sandstones yield abundant cross-beddings, ripple marks and microbially induced sedimentary structures (MISSs) as well as the Claraia-dominated bivalve assemblage of early-middle Griesbachian age, suggesting the relatively high-energy, fair-weather wave action zone in siliciclastic shallow sea. This lowest Triassic ichnoassemblage comprises 17 ichnospecies in 12 ichnogenera and is dominated by Diplocraterion with common presence of Rhizocorallium, Arenicolites, Bifungites, Rosselia, and Skolithos, all of which possess very high complexity and tiering levels, and usually mark ecologic recovery following major biocrises. Such a diverse ichnoassemblage therefore indicates that final stage of post-extinction recovery was much more rapid in the southern Qilian than most areas elsewhere in which biotic recovery usually occurred in Spathian.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-278563

© Copyright 2016 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.