Sequencing events across the Permian-Triassic boundary, Guryul Ravine (Kashmir, India)

Autor(en)

Thomas J. Algeo, Robyn Hannigan, Harry Rowe, Michael Brookfield, Aymon Baud, Leopold Krystyn, Brooks B. Ellwood

Abstrakt

The Permian-Triassic boundary (PTB) section at Guryul Ravine (Kashmir, India) comprises a > 100-m-thick, apparently conformable succession of mixed siliciclastic-carbonate sediments deposited in a deep-shelf or ramp setting. This section, although long important in debates concerning placement of the PTB, has not previously been the focus of an integrated chemostratigraphic study. In the present study, samples from a 20-m-thick interval straddling the PTB were analyzed for major- and trace-element concentrations, TOC-TIC, REEs, and organic delta C-13-delta N-15 to investigate contemporaneous environmental changes. The Guryul Ravine section exhibits a sequence of discrete events that provide potentially important information about the character and cause(s) of the PTB. Two transient negative C-isotopic excursions within the upper changxingensis zone predate the Late Permian event horizon (LPEH, i.e., the global mass extinction event) by similar to 200-400 kyr and are associated with the onset of a major eustatic rise and with secondary extinction peaks. These excursions may record minor environmental disturbances prior to the main end-Permian crisis, supporting an intrinsic mechanism such as volcanism and climate change rather than an extrinsic mechanism such as a bolide impact. The onset of a large (similar to -4.0 to -4.5%), sustained negative C-isotope shift marks the LPEH, which is located at the Zewan-Khunamub formation contact similar to 260 cm below the biostratigraphically defined PTB, The Guryul Ravine section exhibits a stepwise extinction pattern, with the largest peak between the LPEH and PTB and a secondary peak just above the PTB, a pattern similar to that observed in the Meishan D GSSP. (C) 2007 Elsevier B.V. All rights reserved.

Organisation(en)

Institut für Paläontologie

Externe Organisation(en)

University of Cincinnati, Arkansas State University, Jonesboro, University of Kentucky, University of Guelph, Musée cantonal de Géologie Lausanne, Louisiana State University

Journal

Palaeogeography, Palaeoclimatology, Palaeoecology

Band

252

Seiten

328-346

Anzahl der Seiten

19

ISSN

0031-0182

DOI

https://doi.org/10.1016/j.palaeo.2006.11.050

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

105121 Sedimentologie, 105118 Paläontologie, 105105 Geochemie

Schlagwörter

Sustainable Development Goals

SDG 13 – Maßnahmen zum Klimaschutz

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d5e29f86-80b6-4419-8b77-5b95be8a7784