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  • Huvudmeny

Causes and Effects of the Permian-Triassic Biotic Crisis Inferred from Continental Margin Sections and Modeling

Photo: Steve McLoughlin

Late Permian Glossopteris leaf from the Sydney Basin – one of the major casualties of the end-Permian biotic crisis.

Summary

The Late Permian-Early Triassic was marked by major perturbations to the Earth system, including the largest mass extinction of the geological record. This interval saw the final assembly of Pangea, a minimum in the extent of continental flooding by the sea, the development of extreme continentality, and unprecedented expansion of subtropical arid belts.

Geochemical proxy records reveal an Earth system that was primed for catastrophic response to triggers that may have included Siberian Trap volcanism, thermogenic methane and fly ash emission from intrusions into the West Siberian Coal Basin, and/or bolide impact.

This project involves an integrated sedimentological, geochemical, palaeobotanical, and palynological study of the Upper Permian to Lower Triassic stratigraphic records of the Bowen-Gunnedah-Sydney Basin System in eastern Australia, utilizing well-exposed surface sections supported by high-quality, bore core archives. We will synthesize these data with results from climate simulations.

Our investigations will be supported by extensive new, precise geochronological data from the Permian and Triassic succession of eastern Australia and our data will represent a transect through mid-high palaeolatitudes along the Panthalassan margin of Gondwana, allowing us to assess the possibility that the environmental stresses leading to the EPME were not evenly or synchronously distributed.

These environmental stresses identified from stratigraphic records will be integrated with climate sensitivity studies to evaluate possible responses to greenhouse gas, aerosol, and orbital forcing variations.

This research is funded by the National Science Foundation (USA)

External Project Participants

Prof Chris Fielding (principal investigator, sedimentology), University of Nebraska-Lincoln

Dr Tracy Frank (researcher, geochemistry & sedimentology), University of Nebraska-Lincoln

Dr Robert Nicoll (researcher, geochronology), Geoscience Australia

Dr Arne Winguth (researcher, palaeoclimate modelling), University of Texas-Arlington

Dr Cornelia Winguth (researcher, palaeoclimate modelling), University of Texas-Arlington

Selected Publications

McLoughlin, S. 2016. A new genus of glossopterid fructifications from the Artinskian–Changhsingian of eastern Australia. Ameghiniana 53: 586–598.

Edirisooriya, G., Dharmagunawardhane, H.A. & McLoughlin, S., in press-2017. The first record of the Permian Glossopteris flora from Sri Lanka: implications for hydrocarbon source rocks in the Mannar Basin. Geological Magazine