Abstract Preservation of organic carbon (Corg) in marine sediments plays a major role in defining ocean-atmosphere CO2 levels, Earth climate, and the generation of hydrocarbons. Important controls over sedimentary Corg preservation include; biological productivity, Corg isolation from oxidants (mainly dissolved O2) in the overlying water column and sediments, and Corg – mineral association in sediments. Deposition of the products of explosive volcanism (tephra) in the oceans directly enhances Corg burial through all these mechanisms, and indirectly through enhanced formation of authigenic carbonate (Cauth) derived from sedimentary Corg. In the modern oceans, it is suggested that tephra deposition may account for 5–10% of the Corg burial flux and 10–40% of the Cauth burial flux. However, during certain periods in Earth's history, extensive explosive volcanism may have led to enhanced Cauth precipitation on a sufficiently large scale to influence the global ocean-atmosphere carbon cycle. Changes in tephra-related Corg preservation may also have played a role in increasing Corg preservation rates in local marine basins, at the oxic-anoxic boundary and enhanced the generation of hydrocarbon deposits in these settings.

中文翻译：

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火山灰在增强海洋沉积物中有机碳保存中的作用

摘要 海洋沉积物中有机碳 (Corg) 的保存在确定海洋大气 CO2 水平、地球气候和碳氢化合物的生成方面起着重要作用。对沉积 Corg 保存的重要控制包括：生物生产力，Corg 与上覆水柱和沉积物中的氧化剂（主要是溶解的 O2）的分离，以及 Corg – 沉积物中的矿物组合。爆炸性火山作用 (tephra) 产物在海洋中的沉积通过所有这些机制直接增强了 Corg 的埋藏，并通过增强来自沉积 Corg 的自生碳酸盐 (Cauth) 的形成间接增强了 Corg 的埋藏。在现代海洋中，有人认为火山灰沉积可能占 Corg 埋藏通量的 5-10% 和 Cauth 埋藏通量的 10-40%。然而，在地球历史的某些时期，广泛的爆炸性火山活动可能导致足够大的 Cauth 降水增加，从而影响全球海洋 - 大气碳循环。与火山灰相关的 Corg 保存的变化也可能在提高当地海洋盆地的 Corg 保存率方面发挥了作用，在好氧 - 缺氧边界处，并增强了这些环境中碳氢化合物沉积的生成。