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.

人们认为大陆洪水玄武岩火山在地球历史上所有五个最大的群众扩展中都发挥了作用。但是，由于难以确定这些事件的确切时机，这是在10至100千年的时间表上，我们对火山主义如何引起环境变化的理解受到阻碍。富含火山气体的挥发性痕量元素，在洪水盆地火山中注入大气，后来沉积在沉积物中，可以在不到几万年的时间范围内将这些过程连接起来，超出了放射量计的分辨率。以前，沉积物中的汞（HG）浓度已被用作过去火山的代理。我们最近的工作表明，在沉积岩石中的柜（TE）和硒（SE）可能是火山主义更敏感和可靠的代理。该项目将在二叠纪的沉积物概况（包括三叠纪和白垩纪 - 古近期边界）中测量痕量元素（包括HG，TE和SE），以分别将西伯利亚和印度（Deccan）的洪水盆地火山链接起来，并记录在相同的沉积物中，并保持了环境变化的记录，并以相同的沉积物保存，并以几千年代的分辨率分辨出来。对于白垩纪 - 古纪，我们还将能够确定Deccan火山脉冲相对于Chicxulub撞击事件的时机，并检验了最近的假设，即影响引发了最大的Deccan爆发。