Journal
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
Volume 474, Issue -, Pages 140-151Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.palaeo.2016.06.027
Keywords
Mass extinction; Photic zone euxinia; Biomarkers; Permian-Triassic boundary
Funding
- 973 Program [2011CB808800]
- 111 Project [B08030]
- National Natural Science Foundation of China [41202240, 41290262]
- Fundamental Research Funds for National University, China University of Geosciences (Wuhan) [1610491T02]
- Sedimentary Geology and Paleobiology Program of the U.S. National Science Foundation [EAR-1053449]
- NASA Exobiology Program [NNX13ADIG]
- China University of Geosciences-Wuhan (SKL-GPMR program) [GPMR201301]
- China University of Geosciences-Wuhan (SKL-BGEG program) [BGL201407]
Ask authors/readers for more resources
The incursion of euxinic waters into the ocean-surface layer is hypothesized to have been an important killing agent during the end-Permian mass extinction. However, both the causes and extent of oceanic euxinia during this crisis remain poorly known, making assessment of its role in the mass extinction difficult. Here, we document the distribution of aryl isoprenoids (AIs), which are biomarkers of obligate anaerobic green sulfur bacteria (Chlorobiaceae) that are indicative of photic-zone euxinia, in 12 Permian-Triassic Boundary (PTB) sections with a wide distribution globally. Profiles of Al abundance for the 12 study sections show significant spatiotemporal variation. No Als were identified in the shallowest sections, but Als are present both prior to and following the mass extinction in intermediate-depth sections and following the mass extinction in deep-water sections. This pattern suggests a combination of upward and oceanward expansion of photic-zone euxinia during the PTB crisis, possibly fueled by elevated riverine nutrient fluxes as a consequence of climatic warming, terrestrial ecosystem destruction, and enhanced erosion. This hypothesis is supported by the close association of AIs with elevated abundances of moretanes and dibenzofuran (DBF), which are biomarkers for terrestrial erosion. Expansion of oceanic euxinia at intermediate water depths may have established a long-term reservoir that fed episodic incursions of H2S-bearing waters into shallow-marine environments, delaying the recovery of marine ecosystems during the Early Triassic. The biomarker records of the present study thus provide significant evidence of terrestrial-marine linkage during the PTB crisis. (C) 2016 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available