Cai Chunfang, Xu Chenlu, Fakhraee Mojtaba, Chen Daizhao, Peng Yanyan
Key Laboratory of Cenozoic Geology & Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Chaoyang District, Beijing 100029, China.
College of Earth and Planetary Sciences, Beijing 100049, China.
PNAS Nexus. 2022 Jul 30;1(4):pgac122. doi: 10.1093/pnasnexus/pgac122. eCollection 2022 Sep.
Ocean sulfate concentration might have fluctuated greatly throughout the Earth's history and may serve as a window into perturbations in the ocean-atmosphere system. Coupling high-resolution experimental results with an inverse modeling approach, we, here, show an unprecedented dynamic in the global sulfate reservoir during the Frasnian-Famennian (F-F) boundary event, as one of the "Big five" Phanerozoic biotic crises. Notably, our results indicate that, in a relatively short-time scale (∼200 thousand years), seawater sulfate concentration would have dropped from several mM before the Upper Kellwasser Horizon (UKH) to an average of 235 ± 172 μM at the end of the UKH (more than 100 times lower than the modern level) as the result of evaporite deposition and euxinia, and returned to around mM range after the event. Our findings indicate that the instability in the global sulfate reservoir and nutrient-poor oceans may have played a major role in driving the Phanerozoic biological crises.
在地球历史的长河中，海洋硫酸盐浓度可能出现过大幅波动，它或许能为我们洞察海洋 - 大气系统的扰动提供一扇窗口。通过将高分辨率实验结果与反演建模方法相结合，我们在此展示了在弗拉斯阶 - 法门阶（F - F）边界事件期间，全球硫酸盐储库中前所未有的动态变化，该事件是显生宙“五大”生物危机之一。值得注意的是，我们的结果表明，在相对较短的时间尺度（约20万年）内，由于蒸发岩沉积和缺氧环境，海水硫酸盐浓度在上凯尔瓦瑟层位（UKH）之前的数毫摩尔每升下降到UKH末期的平均235±172微摩尔每升（比现代水平低100多倍），并且在事件之后又恢复到大约毫摩尔每升的范围。我们的研究结果表明，全球硫酸盐储库的不稳定性以及贫营养海洋可能在推动显生宙生物危机方面发挥了重要作用。
