Correlating continental flood basalt volcanism, environmental change, and mass extinction events at high resolution using novel geochemical proxies in sediments

使用沉积物中的新型地球化学代理以高分辨率关联大陆洪水玄武岩火山作用、环境变化和大规模灭绝事件

• 批准号: 469078255
• 负责人: Privatdozent Dr. Marcel Regelous
• 金额: --
• 依托单位: GeoZentrum Nordbayern
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/469078255?language=en
• 关键词: Correlating; continental; flood; basalt; volcanism

Continental flood basalt volcanism is thought to have played a role in all five of the largest mass extinctions in Earth history. However, our understanding of how volcanism causes environmental change leading to mass extinction is hampered by difficulty determining the precise timing of these events, which occurred over 10 to 100 thousand-year timescales. Volatile trace elements which are enriched in volcanic gas, injected into the atmosphere during flood basalt volcanism, and later deposited in sediments can potentially link these processes at timescales of less than a few tens of thousands of years, beyond the resolution of radiometric dating. Previously, mercury (Hg) concentrations in sediments have been used as a proxy for past volcanism. Our recent work has shown that tellurium (Te) and selenium (Se), in sedimentary rocks may be more sensitive and reliable proxies for volcanism. This project will measure trace elements (including Hg, Te and Se) in sediment profiles across the Permian – Triassic and Cretaceous – Paleogene boundaries, in order to link flood basalt volcanism in Siberia and in India (Deccan) respectively, with the record of environmental change and extinction preserved in the same sediments, at a resolution of a few tens of thousands of years. For the Cretaceous – Paleogene, we will also be able to determine the timing of Deccan volcanic pulses relative to the Chicxulub impact event, and test the recent hypothesis that the impact triggered the largest Deccan eruptions.

大陆洪水玄武岩火山活动被认为在地球历史上所有五次最大规模的物种灭绝中都发挥了作用，然而，我们对火山活动如何导致环境变化导致大规模灭绝的理解因难以确定这些事件的精确时间而受到阻碍。火山气体中富集的挥发性微量元素在溢流玄武岩火山活动期间注入大气中，随后可能沉积在沉积物中。将这些过程在不到几万年的时间尺度上联系起来，超出了放射性测年的分辨率。此前，沉积物中的汞（Hg）浓度已被用作过去火山活动的替代指标。沉积岩中的 Te）和硒 (Se) 可能是火山活动更敏感、更可靠的代表。该项目将测量二叠纪沉积物剖面中的微量元素（包括 Hg、Te 和 Se）。三叠纪和白垩纪-古近纪边界，以便分别将西伯利亚和印度（德干）的基底洪水火山活动与保存在相同沉积物中的环境变化和灭绝记录联系起来，分辨率为几万年。对于白垩纪 - 古近纪，我们还能够确定德干火山脉冲相对于希克苏鲁伯撞击事件的时间，并检验最近的假设，即撞击引发了最大的撞击。德干火山喷发。