Collaborative Research: The end Guadalupian (ca 260 Ma) biotic crisis: Research into timing, potential causes, and environmental proxies

合作研究：瓜达卢普阶（ca 260 Ma）生物危机的终结：对时间、潜在原因和环境代理的研究

• 批准号: 0923669
• 负责人: Roland Mundil
• 金额: $ 29.99万
• 依托单位: Berkeley Geochronology Center
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0923669&HistoricalAwards=false
• 关键词: Collaborative; Research; end; Guadalupian; ca

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Collaborative Research: The end Guadalupian (ca 260 Ma) biotic crisis: Research into timing, potential causes, and environmental proxiesRoland Mundil and Paul Renne: Berkeley Geochron LaboratoryJohathan Payne: Stanford UniversityEAR-0923669 and EAR-0923620ABSTRACTHigh-resolution geochronology is instrumental in testing proposed causal links between continental-scale, short-term volcanic events and environmental crises. This collaborative research proposal is aimed at unraveling the timing of the end-Guadalupian (ca 260 Ma) mass extinction and its temporal relation to the Emeishan volcanic province in W China. Geochronological research will be complemented with paleo-enviromental studies (delta13C stratigraphy) and biostratigraphy.Currently existing geochronological and paleo-environmental data suggest a causal link but are scarce and insufficient for testing this hypothesis with confidence, because age data constraining the Emeishan volcanism and the extinction event are imprecise and inaccurate (with several Ma uncertainties), and delta13C studies are restricted to short profiles from only a few sites. Therefore, fundamental questions remain unanswered. In addition to testing the hypothesis of a causal link PIs intend to study (1) to what extent the extinction event is diachronous among localities and environments (2) the rate of the biotic recovery in the Late Permian (3) the correlation of extrema in ocean chemistry (if present) with pulses of volcanism and with rates and modes of recovery.In detail, PIs will analyze minerals (zircon, sanidine) from ash-layers within marine and terrestrial sections recording the end-Guadalupian event in China and Australia, applying a zircon pre-treatment which is proven to dramatically improve the quality and reliability of high-resolution TIMS U-Pb zircon data by eliminating the effects of Pb loss. 40Ar/39Ar dating will be employed as a further constraint. In addition to the sedimentary sections they will target Emeishan volcanic products with both U-Pb and 40Ar/39Ar analyses applied to zircon and baddeleyite, and plagioclase, respectively.Through careful integration of U-Pb and 40Ar/39Ar geochronology with chemo- and biostratigraphy, the time scale of the Middle through Late Permian will be greatly improved and will lead to more realistic evaluation of potential causes for the biotic crisis and its aftermath.The research proposed herein is of fundamental importance to understanding first-order processes in Earth History. In particular the understanding of environmental anomalies has become a prime focus of research in Earth Sciences and other areas. PIs will make their findings accessible to a wider audience by collaborating with the University of California Museum of Paleontology and their public outreach program.

该奖项由 2009 年美国复苏和再投资法案（公法 111-5）资助。 合作研究：瓜达卢普阶（约 260 Ma）生物危机的终结：对时间、潜在原因和环境指标的研究 Roland Mundil 和 Paul Renne：伯克利 Geochron 实验室 Johathan Payne：斯坦福大学EAR-0923669 和 EAR-0923620摘要高分辨率地质年代学有助于测试大陆范围内的短期火山事件与环境危机之间的因果关系。这项合作研究计划旨在揭示瓜达卢普世末期（约 260 Ma）大规模灭绝的时间及其与中国西部峨眉山火山省的时间关系。地质年代学研究将与古环境研究（δ13C地层学）和生物地层学相辅相成。目前现有的地质年代学和古环境数据表明存在因果关系，但缺乏且不足以可靠地检验这一假设，因为限制峨眉山火山活动和灭绝事件的年龄数据不精确和不准确（有数个Ma）。 不确定性），而 delta13C 研究仅限于来自少数站点的简短概况。因此，基本问题仍未得到解答。除了测试因果关系的假设之外，PI 还打算研究 (1) 灭绝事件在不同地点和环境之间的历时性程度 (2) 二叠纪晚期的生物恢复速度 (3) 海洋化学极值（如果存在）与火山活动脉冲以及恢复速度和模式的相关性。具体而言，PI 将分析灰层中的矿物质（锆石、透石） 在记录中国和澳大利亚瓜达卢普期末事件的海洋和陆地剖面中，应用锆石预处理，事实证明，通过消除 Pb 损失的影响，可以显着提高高分辨率 TIMS U-Pb 锆石数据的质量和可靠性。 40Ar/39Ar 测年将被用作进一步的限制。除了沉积剖面外，他们还将针对峨眉山火山产物，分别对锆石、斜斜长石和斜长石进行 U-Pb 和 40Ar/39Ar 分析。通过将 U-Pb 和 40Ar/39Ar 地质年代学与化学地层学和生物地层学仔细整合，中二叠世到晚二叠世的时间尺度将得到极大改善，并将带来更现实的评估 生物危机及其后果的潜在原因。本文提出的研究对于理解地球历史中的一级过程具有根本重要性。特别是对环境异常的理解已成为地球科学和其他领域研究的主要焦点。 PI 将通过与加州大学古生物学博物馆及其公共外展计划合作，向更广泛的受众展示他们的发现。