SGER: Deccan Volcanism Implicated in K-T Mass Extinction

SGER：德干火山活动与 K-T 大规模灭绝有关

• 批准号: 0750664
• 负责人: Gerta Keller
• 金额: --
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2009-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0750664&HistoricalAwards=false
• 关键词: SGER; Deccan; Volcanism; Implicated; Mass

The biotic effects of Deccan volcanism and its potential impact on the K-T mass extinction are perhaps the major unsolved problems in K-T studies today. Recent studies indicate that the bulk (80%) of the Deccan trap eruptions occurred over less than 0.8 m.y. in magnetic polarity C29r spanning the Cretaceous-Tertiary (K-T) boundary and that the last Deccan eruption occurred in the early Danian C29n. These two Deccan Traps form the longest lava flows extending 1000 km across India and out to the Sea of Bengal. However, determining just where within the C29r major eruptive phase the K-T mass extinction occurred has remained problematic because intertrappean sediments were generally deposited in fluvial or estuarine environments, which provide poor age control. As a result, models estimating the biotic and environmental consequences of Deccan volcanism have generally underestimated the rate and quantity of Deccan gas emissions by orders of magnitude leading to conclusions that volcanism could not have caused the K-T mass extinction. PIs preliminary investigations of the intertrappean sediments in shallow marine sequences of the Krishna-Godavari Basin in SE India revealed that the major Deccan C29r volcanic eruptions ended at the K-T mass extinction, which suggests that volcanism and impact(s) may have caused this catastrophe.In this project PIs propose to investigate the onset, duration and end of the main phase of C29r Deccan volcanism and its biotic consequences in the marine realm as well as the dinosaur extinction and C29n volcanism and its relationship to the long delayed early Danian biotic recovery. Specifically, they will test two hypotheses: (1) Deccan volcanism played a crucial role in the K-T mass extinction, and (2) Deccan volcanism is responsible for the long-delayed biotic recovery after the mass extinction. PIs plan to accomplish this by building on their initial discovery that the main Deccan volcanic phase ended at the K-T mass extinction (Rajahmundry and Meghalaya) and by analyzing new drill cores that recover intertrappean and infratrappean sediments of the two longest Deccan Trap lava flows. The results of this project may open the contentious mass extinction debate to potentially transformative research ideas by directly linking mass extinctions to large igneous provinces.This research is jointly funded with NSF's Office of International Science and Engineering.

德干火山的生物效应及其对K-T大灭绝的潜在影响可能是当今K-T研究中尚未解决的主要问题。最近的研究表明，德干圈闭的大部分(80%)喷发发生在不到0.8英里的时间内。在横跨白垩纪-第三纪(K-T)界线的磁极C29r中，最后一次德干喷发发生在大年C29n早期。这两个德干陷阱形成了最长的熔岩流，横跨印度绵延1000公里，一直延伸到孟加拉海。然而，确定C29r主要喷发阶段K-T大规模灭绝发生在哪里仍然是一个问题，因为圈闭间沉积物通常沉积在河流或河口环境中，这提供了较差的年龄控制。因此，估计德干火山的生物和环境后果的模型通常以数量级低估了德干火山气体排放的速度和数量，从而得出火山活动不可能导致K-T大灭绝的结论。PIS对印度东南部Krishna-Godavari盆地浅海层序中的圈闭间沉积进行了初步调查，发现主要的德干C29r火山喷发在K-T大灭绝时结束，这表明火山作用和冲击(S)可能导致了这场灾难。在这个项目中，PIS建议调查C29r德干火山作用的主要阶段的开始、持续时间和结束及其对海洋生物的影响，以及恐龙灭绝和C29n火山作用及其与拖延已久的早期达尼安生物恢复的关系。具体地说，他们将检验两个假设：(1)德干火山作用在K-T大灭绝中发挥了关键作用，(2)德干火山作用是大灭绝后拖延已久的生物恢复的原因。PIS计划通过以下方式实现这一目标：根据他们的初步发现，主要的德干火山阶段在K-T大灭绝(Rajahmunry和Meghalaya)结束时结束，并分析新的钻芯，这些核心回收了两个最长的德干圈闭熔岩流的圈闭间和圈闭下沉积物。该项目的结果可能会通过直接将大规模灭绝与大型火成岩省联系起来，开启有争议的大规模灭绝辩论，从而产生潜在的变革性研究想法。这项研究是与美国国家科学基金会国际科学与工程办公室联合资助的。