Environmental controls on marine ecosystem recovery following mass extinctions, with an example from the Early Triassic Hengye Wei a,b, ⁎, Jun Shen a,c , Shane D. Schoepfer d , Leo Krystyn e , Sylvain Richoz f , Thomas J. Algeo a,c,g, ⁎⁎ a Department of Geology, University of Cincinnati, Cincinnati, OH 45221, USA b College of Earth Science, East China Institute of Technology, Nanchang, Jiangxi 330013, PR China c State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei 430074, PR China d Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA e Institute for Paleontology, Vienna University, Althanstrasse 14, 1090 Vienna, Austria f Institute of Earth Sciences, Graz University, Heinrichstrasse 26, 8020 Graz, Austria g State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei 430074, PR China abstract article info Article history: Received 25 April 2014 Accepted 21 October 2014 Available online xxxx Keywords: Productivity Redox Anoxia Weathering South China India The recovery of marine ecosystems following a mass extinction event involves an extended interval of increasing biotic diversity and ecosystem complexity. The pace of recovery may be controlled by intrinsic ecosystem or extrinsic environmental factors. Here, we present an analysis of changes in marine conditions following the end-Permian mass extinction with the objective of evaluating the role of environmental factors in the protracted (~5-Myr-long) recovery of marine ecosystems during the Early Triassic. Specifically, our study examines changes in weathering, productivity, and redox proxies in three sections in South China (Chaohu, Daxiakou, and Zuodeng) and one in northern India (Mud). Our results reveal: 1) recurrent environmental perturbations during the Early Triassic; 2) a general pattern of high terrestrial weathering rates and more intensely reducing marine redox con- ditions during the early Griesbachian, late Griesbachian, mid-Smithian, and (more weakly) the mid-Spathian; 3) increases in marine productivity during the aforementioned intervals except for the early Griesbachian; and 4) stronger and more temporally discrete intervals of environmental change in deepwater sections (Chaohu and Daxiakou) relative to shallow and intermediate sections (Zuodeng and Mud). Our analysis reveals a close relationship between episodes of marine environmental deterioration and a slowing or reversal of ecosystem recovery based on metrics of biodiversity, within-community (alpha) diversity, infaunal burrowing, and ecosys- tem tiering. We infer that the pattern and pace of marine ecosystem recovery was strongly modulated by recur- rent environmental perturbations during the Early Triassic. These perturbations were associated with elevated weathering and productivity fluxes, implying that nutrient and energy flows were key influences on recovery. More regular secular variation in deepwater relative to shallow-water environmental conditions implies that perturbations originated at depth (i.e., within the oceanic thermocline) and influenced the ocean-surface layer irregularly. Finally, we compared patterns of environmental disturbance and ecosystem recovery following the other four “Big Five” Phanerozoic mass extinctions to evaluate whether commonalities exist. In general, the pace of ecosystem recovery depends on the degree of stability of the post-crisis marine environment. © 2014 Elsevier B.V. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 2.1. The end-Permian biotic crisis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 2.2. The Early Triassic marine ecosystem recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 2.3. Environmental change during the Early Triassic recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 3. Study sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Earth-Science Reviews xxx (2014) xxx–xxx ⁎ Correspondence to: H. Wei, College of Earth Science, East China Institute of Technology, Nanchang, Jiangxi 330013, PR China. Tel.: +86 18870073972. ⁎⁎ Correspondence to: T.J. Algeo, State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei 430074, PR China. Tel.: +86 513 5564195. E-mail addresses: weihengye@163.com (H. Wei), Thomas.Algeo@uc.edu (T.J. Algeo). EARTH-02045; No of Pages 28 http://dx.doi.org/10.1016/j.earscirev.2014.10.007 0012-8252/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Please cite this article as: Wei, H., et al., Environmental controls on marine ecosystem recovery following mass extinctions, with an example from the Early Triassic, Earth-Sci. Rev. (2014), http://dx.doi.org/10.1016/j.earscirev.2014.10.007