Climate warming, euxinia and carbon isotope perturbations during the Carnian (Triassic) Crisis in South China

Sun, Y.D.; Wignall, P.B.; Joachimski, M.M.; Bond, D.P.G.; Grasby, S.E.; Lai, X.L.; Wang, L.N.; Zhang, Z.T.; Sun, S.

Abstract

The Carnian Humid Episode (CHE), also known as the Carnian Pluvial Event, and associated biotic changes are major enigmas of the Mesozoic record in western Tethys. We show that the CHE also occurred in eastern Tethys (South China), suggestive of a much more widespread and probably global climate perturbation. Oxygen isotope records from conodont apatite indicate a double-pulse warming event. The CHE coincided with an initial warming of 4 °C. This was followed by a transient cooling period and then a prolonged ~7 °C warming in the later Carnian (Tuvalian 2). Carbon isotope perturbations associated with the CHE of western Tethys occurred contemporaneously in South China, and mark the start of a prolonged period of carbon cycle instability that persisted until the late Carnian. The dry-wet transition during the CHE coincides with the negative carbon isotope excursion and the temperature rise, pointing to an intensification of hydrologic cycle activities due to climatic warming. While carbonate platform shutdown in western Tethys is associated with an influx of siliciclastic sediment, the eastern Tethyan carbonate platforms are overlain by deep-water anoxic facies. The transition from oxygenated to euxinic facies was via a condensed, manganiferous carbonate (MnO content up to 15.1 wt%), that records an intense Mn shuttle operating in the basin. Significant siliciclastic influx in South China only occurred after the CHE climatic changes and was probably due to foreland basin development at the onset of the Indosinian Orogeny. The mid-Carnian biotic crisis thus coincided with several phenomena associated with major extinction events: a carbonate production crisis, climate warming, δ 13 C oscillations, marine anoxia, biotic turnover and flood basalt eruptions (of the Wrangellia Large Igneous Province).

Citation

Sun, Y., Wignall, P., Joachimski, M., Bond, D., Grasby, S., Lai, X., Wang, L., Zhang, Z., & Sun, S. (2016). Climate warming, euxinia and carbon isotope perturbations during the Carnian (Triassic) Crisis in South China. Earth and planetary science letters, 444, 88-100. https://doi.org/10.1016/j.epsl.2016.03.037

• Journal Article Type: Article
• Acceptance Date: Mar 18, 2016
• Online Publication Date: Apr 8, 2016
• Publication Date: Jun 15, 2016
• Deposit Date: Mar 31, 2016
• Publicly Available Date: Apr 8, 2016
• Journal: Earth and planetary science letters
• Print ISSN: 0012-821X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 444
• Pages: 88-100
• DOI: https://doi.org/10.1016/j.epsl.2016.03.037
• Keywords: Carnian Humid Episode; Carbon isotopes; Marine anoxia; Climate warming; Wrangellia flood basalt; Large igneous provinces
• Public URL: https://hull-repository.worktribe.com/output/434473
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0012821X16301248
• Additional Information: This article is maintained by: Elsevier; Article Title: Climate warming, euxinia and carbon isotope perturbations during the Carnian (Triassic) Crisis in South China; Journal Title: Earth and Planetary Science Letters; CrossRef DOI link to publisher maintained version: http://dx.doi.org/10.1016/j.epsl.2016.03.037; Content Type: article; Copyright: © 2016 Elsevier B.V. All rights reserved.
• Contract Date: Mar 31, 2016