Marine Os isotopic evidence for multiple volcanic episodes during Cretaceous Oceanic Anoxic Event 1b
Marine Os isotopic evidence for multiple volcanic episodes during Cretaceous Oceanic Anoxic Event 1b
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DOI：
10.1038/s41598-020-69505-x
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发表时间：
2020-07
影响因子：
4.6
通讯作者：
H. Matsumoto;J. Kuroda;R. Coccioni;F. Frontalini;S. Sakai;N. Ogawa;N. Ohkouchi
中科院分区：
文献类型：
--
作者：
H. Matsumoto;J. Kuroda;R. Coccioni;F. Frontalini;S. Sakai;N. Ogawa;N. Ohkouchi
白垩纪期间的一次主要海洋扰动，被称为海洋缺氧事件（OAE） 1b，标志着Aptian-Albian边界。克尔盖伦高原南部广泛的火山事件被认为是OAE1b的触发因素，但仍缺乏令人信服的证据。在这里，我们重建了特提斯和太平洋远洋沉积记录中横跨阿普提亚-阿尔比安边界的海洋Os同位素比率的时间变化，以阐明OAE1b、生物转换和火山事件之间的因果关系。我们的新Os同位素记录显示，在OAE1b期间，两个负峰值与浮游有孔虫在Aptian-Albian边界上的转换有关，表明多次海底火山事件。通过比较Os同位素剖面与碳酸盐碳同位素组成、caco3含量和黏结有孔虫的相对丰度，我们得出结论，OAE1b时期大量火山喷发释放的二氧化碳引起的海洋酸化可能促进了主要浮游有孔虫的更替。
The Aptian–Albian boundary is marked by one of the major oceanic perturbations during the Cretaceous, called Oceanic Anoxic Event (OAE) 1b. Extensive volcanic episodes at the Southern Kerguelen Plateau has been suggested as the trigger of OAE1b, but compelling evidence remains lacking. Here, we reconstructed the temporal variations of marine Os isotopic ratios across the Aptian–Albian boundary in the Tethyan and Pacific pelagic sedimentary records to elucidate the causal links between OAE1b, the biotic turnover, and volcanic episodes. Our new Os isotopic records show two negative spikes that correlate with a period of planktonic foraminiferal turnover across the Aptian–Albian boundary during OAE1b and suggest multiple submarine volcanic events. By comparing our Os isotopic profile with carbon isotopic compositions of carbonate, CaCO3content, and the relative abundances of agglutinated foraminifera, we conclude that ocean acidification caused by the massive release of CO2through extensive volcanic episodes could have promoted the major planktonic foraminiferal turnover during OAE1b.