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

该奖项是根据2009年美国复苏和再投资法案资助的（公法111-5）。合作研究：结束瓜达卢佩（约260 Ma）生物危机：时间，潜在原因和环境代理的研究Roland Mundil和Paul Renne：Berkeley Geochron鉴定Johathan Payne：斯坦福大学高分辨率地质年代学有助于检验大陆规模的短期火山事件与环境危机之间的因果关系。这项合作研究的建议，旨在解开结束瓜达卢佩（约260马）的大规模灭绝的时间和它的时间关系，在中国西部的峨眉山火山省。地质年代学研究将与古环境研究相辅相成目前已有的年代学和古环境数据表明存在因果关系，但由于制约峨眉山火山活动和灭绝事件的年龄数据不精确，不足以可信地检验这一假设（有几个马的不确定性），和delta 13 C的研究仅限于短配置文件从少数网站。因此，根本问题仍然没有答案。除了检验因果联系的假设外，PI还打算研究（1）灭绝事件在多大程度上是跨地区和环境的（2）晚二叠世生物恢复的速度（3）海洋化学极值的相关性（如果存在）与火山活动的脉冲以及恢复的速率和模式。详细地说，对中国和澳大利亚Guadalupian末事件的海陆剖面中的火山灰层（锆石，透长石）进行了锆石预处理，消除了Pb损失的影响，显著提高了高分辨率TIMS锆石U-Pb数据的质量和可靠性。40 Ar/39 Ar定年法将被用作进一步的限制。除沉积剖面外，还将对峨眉山火山产物分别进行锆石、斜锆石和斜长石的U-Pb和40 Ar/39 Ar分析，通过U-Pb和40 Ar/39 Ar年代学与化学和生物地层学的结合，中二叠世至晚二叠世的时间尺度将大大提高，并将导致对潜在原因的更现实的评估。生物危机及其后果。这里提出的研究是根本的重要性，以了解在地球历史上的一阶过程。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，让更广泛的受众了解他们的发现。

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.