Novas pistas do que pode ter provocado a extinção mais catastrófica mundial há aproximadamente 252 milhões de anos atrás

quinta-feira, agosto 03, 2017

Initial pulse of Siberian Traps sills as the trigger of the end-Permian mass extinction

S. D. Burgess, J. D. Muirhead & S. A. Bowring

Nature Communications 8, Article number: 164 (2017)


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Geology Natural hazards Palaeoclimate Volcanology

Received: 31 October 2016 Accepted: 31 May 2017

Published online: 31 July 2017

Source/Fonte: YouTube

Abstract

Mass extinction events are short-lived and characterized by catastrophic biosphere collapse and subsequent reorganization. Their abrupt nature necessitates a similarly short-lived trigger, and large igneous province magmatism is often implicated. However, large igneous provinces are long-lived compared to mass extinctions. Therefore, if large igneous provinces are an effective trigger, a subinterval of magmatism must be responsible for driving deleterious environmental effects. The onset of Earth’s most severe extinction, the end-Permian, coincided with an abrupt change in the emplacement style of the contemporaneous Siberian Traps large igneous province, from dominantly flood lavas to sill intrusions. Here we identify the initial emplacement pulse of laterally extensive sills as the critical deadly interval. Heat from these sills exposed untapped volatile-fertile sediments to contact metamorphism, likely liberating the massive greenhouse gas volumes needed to drive extinction. These observations suggest that large igneous provinces characterized by sill complexes are more likely to trigger catastrophic global environmental change than their flood basalt- and/or dike-dominated counterparts.

Acknowledgements

The authors would like to acknowledge J.T. Hagstrum and B. Schoene for thoughtful comments, and A.R. Van Eaton, A.T. Calvert, M.A. Coble, D.T. Downs, J.A. Vazquez, and C.R. Bacon for discussion during development of this manuscript. S.D.B. would like to acknowledge the USGS Mendenhall postdoctoral program.

Author information

Affiliations

U.S. Geological Survey, Volcano Science Center, 345 Middlefield Road, Mail Stop 910, Menlo Park, CA, 94025, USA

S. D. Burgess

Department of Earth Sciences Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY, 13244, USA

J. D. Muirhead

Earth, Atmospheric, and Planetary Sciences Department Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA

S. A. Bowring

Contributions

S.D.B. wrote the manuscript. J.D.M. and S.A.B. contributed intellectual and editorial advisement.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to S. D. Burgess.