Marine diagenesis of tephra aided the Palaeocene-Eocene Thermal Maximum termination
Marine diagenesis of tephra aided the Palaeocene-Eocene Thermal Maximum termination
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DOI：
10.1016/j.epsl.2021.117101
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发表时间：
2021-10
影响因子：
5.3
通讯作者：
Jack Longman;T. Gernon;M. Palmer;Morgan T. Jones;E. Stokke;H. Svensen
中科院分区：
文献类型：
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作者：
Jack Longman;T. Gernon;M. Palmer;Morgan T. Jones;E. Stokke;H. Svensen
古新世-始新世最热时期是一个全球变暖剧烈的时期，开始于5590万年前，持续了大约17万年。人们提出了导致这种变暖的各种机制，包括北大西洋火成岩省(NAIP)的侵位。同样，还援引了许多机制来解释海洋-大气系统对促进恢复到更温和条件所必需的碳的封存。在这里，我们认为碳固定的一条重要途径是与奈普火山作用联系在一起的，这是通过在盖层内碳酸钙(CaCO3)胶结物的沉淀来实现的。这些胶结物是在古新世晚期和始新世早期，在北大西洋大片海域沉积和埋藏了特弗拉之后形成的。我们发现强有力的证据表明，自生碳酸钙胶结物是在特弗拉沉积后不久形成的。蒙特卡罗模拟表明，在PETM恢复阶段，这一过程可能导致了四分之一的碳被封存，提供了一个主要的、但以前没有考虑到的同位素轻质碳的汇，而且可能一直持续到始新世。
The Palaeocene-Eocene Thermal Maximum (PETM) was a period of intense global warming that began ∼55.9 million years ago and lasted about 170,000 yrs. Various mechanisms have been proposed to cause this warming, including the emplacement of the North Atlantic Igneous Province (NAIP). Equally, many mechanisms have been invoked to explain sequestration of carbon from the ocean-atmosphere system necessary to promote the recovery to more temperate conditions. Here we propose that an important path for carbon sequestration was tied to NAIP volcanism through the precipitation of calcium carbonate (CaCO3) cements within the tephra layers. These cements formed after the deposition and burial of tephra over a wide area of the North Atlantic Ocean during the late Palaeocene and early Eocene. We find strong evidence that authigenic CaCO3cements formed shortly after tephra deposition. Monte Carlo simulations suggest that this process may have been responsible for a quarter of the carbon sequestered during the PETM recovery phase, providing a major, but previously unconsidered sink of isotopically-light carbon, and one which may have persisted into the Eocene.