Collaborative Research: Flood volcanism and environmental impacts -- A multidisciplinary investigation of the Deccan Traps and events at the Cretaceous-Paleogene boundary

合作研究：洪水火山活动和环境影响——对德干地盾和白垩纪-古近纪边界事件的多学科调查

• 批准号: 1615203
• 负责人: Michael Manga
• 金额: $ 97.61万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1615203&HistoricalAwards=false
• 关键词: Collaborative; Research; Flood; volcanism; environmental

Increasing evidence suggests that the four most recent mass extinction events: end-Guadalupian; end-Permian; Triassic-Jurassic boundary; Cretaceous-Paleogene boundary (KPB)- are closely associated in time with continental flood basalt (CFB) volcanism. Paradoxically, the KPB is associated with both the Deccan Traps CFB and the Chicxulub impact in Yucatan, Mexico, engendering an intense three-decades-old debate over causal relationships. Deccan volcanism began well before and continued well after KPB/Chicxulub time, but the largest Deccan eruptions (Wai Sub-group) appear to have been initiated within ~50,000 years of both the KPB and the Chicxulub impact, suggesting that this subset of eruptions may have been triggered by the impact. It remains unclear whether large Deccan flood basalt eruptions or the Chicxulub impact (or both) were the cause of the KPB extinction, because both may have injected massive amounts of volatiles, aerosols, and particulates into the atmosphere. This project's research will improve our understanding of the genesis, timing, and environmental effects of Deccan Traps volcanism by considering Earth systems interactions from mantle plume convection to crustal magmatism to eruption and to atmosphere/biosphere effects. The research will include studies of: (1) The genesis and geodynamic context of Deccan magmatism based on physical volcanology and geochemical signatures, coupled with analysis of volatile contents; (2) Radioisotopic geochronology of the Deccan Traps to tightly constrain their eruptive tempo and relation to other KPB events; (3) Geophysical modeling of mantle and crustal magmatic processes, launching of volatiles and aerosols by the Deccan eruptions, and mechanisms of volcanic triggering by dynamic (seismic) stresses due to earthquakes and impacts; (4) Analysis of geophysical exploration data from offshore western India that has not previously been integrated into the main on-land Deccan stratigraphy. Results of these studies will be compared with other Phanerozoic CFB events, some of which are and, importantly, some of which are not associated with mass extinction.

越来越多的证据表明，最近的四个大规模灭绝事件：终结者；末期；三叠纪 - 19.白垩纪 - 果仁元边界（KPB）与大陆洪水盆地（CFB）火山之间的时间密切相关。矛盾的是，KPB与Deccan陷阱CFB和墨西哥尤卡坦的Chicxulub撞击都相关，引发了关于因果关系的激烈的三年历史的辩论。 Deccan火山作用始于之前，在KPB/Chicxulub时间之后一直持续，但是最大的Deccan爆发（WAI亚组）似乎在KPB和Chicxulub撞击的50,000年内开始启动，这表明这一爆发可能受到影响。目前尚不清楚大型Deccan洪水玄武岩爆发或Chicxulub撞击（或两者）是否是KPB灭绝的原因，因为两者都可能将大量挥发物，气溶胶和颗粒物注入了大气中。该项目的研究将通过考虑地球系统的相互作用，从地幔羽流对流到地壳岩浆到喷发以及大气/生物圈效应，从而提高我们对Deccan陷阱火山陷阱的起源，时机和环境影响的理解。该研究将包括：（1）基于物理火山学和地球化学特征的Deccan岩浆作用的生殖和地球动力学背景，再加上挥发物含量的分析； （2）Deccan陷阱的放射性分类学，以严格限制其喷发节奏和与其他KPB事件的关系； （3）地幔和地壳岩浆过程的地球物理模型，通过Deccan爆发来发射挥发物和气溶胶，以及由于地震和影响而引起的动态（地震）应力引起的火山触发机制； （4）分析印度西部海上西部的地球物理勘探数据，该数据以前尚未纳入主要的德干地层。这些研究的结果将与其他原始CFB事件进行比较，其中一些事件是，其中一些事件与质量灭绝无关。