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An astronomical timescale for the Permian-Triassic mass extinction reveals a two-step, million-year-long terrestrial crisis in South China

Hua, Fanghui; Shao, Longyi; Zhang, Tianchang; Bond, David P.G.; Wang, Xuetian; Wang, Juan; Yan, Zhiming; Lu, Jing; Hilton, Jason


Fanghui Hua

Longyi Shao

Tianchang Zhang

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David Bond
Palaeoenvironmental Scientist and Schools Liason Officer

Xuetian Wang

Juan Wang

Zhiming Yan

Jing Lu

Jason Hilton


The Permian-Triassic Mass Extinction (PTME) is the greatest biotic crisis of the Phanerozoic. In terrestrial settings, the PTME appears to have been diachronous and it has been suggested that losses initiated before the marine crisis. We examine organic carbon-isotope (δ13Corg) and geochemical proxies for environmental change in a palaeotropical wetland succession from southwest China. A newly constructed astronomical timescale provides a temporal framework for constraining the timing of the terrestrial PTME. Two major, negative carbon isotope excursions (CIEs) of 5.3‰ and 3.9‰ are observed between the top of the (Permian) Xuanwei Formation and the middle of the (Permian-Triassic) Kayitou Formation respectively. Our cyclostratigraphic model suggests that carbon cycle destabilization lasted ∼0.6 ± 0.1 Myr. We calculate total erosion rates for basaltic landscapes as a proxy for volumes of bare soil resulting from deforestation. Two phases of accelerated erosion saw denudation rates rise over a ∼1 Myr period from ∼150 t/km2/yr in the upper Xuanwei Formation (Permian) to >2000 t/km2/yr at the base of the Dongchuan Formation (Triassic). Calibrating the collapse of terrestrial ecosystems indicates that although the equatorial terrestrial PTME initiated before the marine crisis, it was a protracted process with the final coup-de-grâce not until ∼ 700 ky later. This has a bearing on extinction scenarios in which the terrestrial PTME is a causal factor in marine losses via enhanced nutrient runoff, because the final devastation on land post-dates the much more abrupt marine PTME.


Hua, F., Shao, L., Zhang, T., Bond, D. P., Wang, X., Wang, J., …Hilton, J. (2023). An astronomical timescale for the Permian-Triassic mass extinction reveals a two-step, million-year-long terrestrial crisis in South China. Earth and planetary science letters, 605, Article 118035.

Journal Article Type Article
Acceptance Date Jan 28, 2023
Online Publication Date Feb 9, 2023
Publication Date Mar 1, 2023
Deposit Date Jan 31, 2023
Publicly Available Date Feb 10, 2023
Journal Earth and planetary science letters
Print ISSN 0012-821X
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 605
Article Number 118035
Keywords Permian-Triassic; Astrochronology; Carbon isotopes; Mass extinction; Terrestrial plants; South China
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