中国地质大学David B. Kemp团队最新的研究揭示了早侏罗世大规模碳释放的时间和持续时间。2024年9月10日出版的《地质学》杂志发表了这项成果。

Toarcian海洋缺氧事件(T-OAE, ca.183Ma)是显生宙最重要的变暖事件之一，与大规模碳排放、物种大灭绝以及水文和海洋化学的扰动有关。然而，这种过热的年龄和持续时间长期以来一直不确定，阻碍了人们对碳释放的时间和速度，以及相关的环境和生物变化的理解。

该研究团队提供了高精度的放射性同位素数据，涵盖了生物地层学限制的日本T-OAE记录。地质年代学结果显示，T-OAE持续时间出乎意料地短，约为300k.y.，并与Ferrar大火成岩省(LIP)岩浆活动在时间上重合。

结果驳斥了先前将T-OAE与早期Karoo LIP联系在一起的研究工作，这与早期在Pliensbachian-Toarcian边界的碳循环扰动相一致。研究结果表明，这两个事件都是由极快(可能是次千年尺度)的热成因碳脱气所驱动的。

附：英文原文

Title: The timing and duration of large-scale carbon release in the Early Jurassic

Author: David B. Kemp, Jahandar Ramezani, Kentaro Izumi, Aisha Al-Suwaidi, Chunju Huang, Wenhan Chen, Yuqing Zhu

Issue&Volume: 2024-09-10

Abstract: The Toarcian oceanic anoxic event (T-OAE, ca. 183 Ma) in the Early Jurassic was one of the most significant warming events of the Phanerozoic, associated with large-scale carbon emissions, mass extinction, and perturbations to hydrology and ocean chemistry. However, the age and duration of this hyperthermal have long been uncertain, hindering our understanding of the timing and pace of carbon release and the associated environmental and biotic changes. We present high-precision radioisotopic dates bracketing a biostratigraphically constrained record of the T-OAE in Japan. Our geochronology reveals an unexpectedly short T-OAE duration of ～300 k.y. and a temporal coincidence with Ferrar large igneous province (LIP) magmatism. Our dates refute previous work linking the T-OAE to the earlier Karoo LIP, which was coincident with an earlier carbon cycle perturbation at the PliensbachianToarcian boundary. Our results suggest both events were driven by extremely rapid (perhaps sub-millennial scale) thermogenic carbon degassing during LIP sill intrusion.

DOI: 10.1130/G52457.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G52457.1/648350/The-timing-and-duration-of-large-scale-carbonredirectedFrom=fulltext