Collaborative Research: Terrestrial Late Permian to Early Triassic Earth Systems in NE Pangea: Insights into the Tempo, Effects, and Causes of the End-Permian Mass Extinction

摘要：解释该项目更广泛意义的非技术性描述在地球历史上的不同时期都发生过大规模的物种灭绝。最著名的灭绝发生在白垩纪末期恐龙的灭绝，但人们认为最大规模的灭绝发生在二叠纪末期，大约2.52亿年前。海洋领域的灭绝是全球性的，发生在相对较短的时间间隔内。然而，陆地环境中的事件只有很少的记录。该项目将研究在这些灭绝期间形成的湖泊、河流和古代土壤中充分暴露的沉积岩序列。这项研究将能够精确地记录陆地上的事件顺序，全面分析事件发生之前、期间和之后发生的环境变化，并调查陆生动植物如何应对这些变化。研究结果将确定大陆上的物种灭绝是否与海洋中的物种灭绝同时发生，以及可能导致如此大规模变化的存在条件。考虑到目前对物种灭绝速度的担忧，了解过去发生的过程将有助于确定动植物主要变化背后的原因。该项目将开发博物馆展览和外展计划，向教育和普通观众提供信息。对地球历史的关键时期进行全面的、多学科的调查，可以最好地了解重大生物危机之前、期间和之后的普遍状况。二叠纪-三叠纪大灭绝被用作生物和物理系统如何响应主要气候变化的模型，包括那些归因于温室气体增加的气候变化。目前，二叠纪-三叠纪大灭绝被解释为海洋和陆地生态系统的双重灾难性崩溃，两者都经历了长期的生态群落重构和稳定的生态系统动态恢复。中国博格达山脉具有完整的陆相地层，跨越河流和湖泊沉积交替的临界层段，具有广泛的古土壤记录，可以推导出成土趋势和地球化学模式。包括主要动植物群在内的古生物学记录保存完好。试点项目数据显示，该剖面的岩石中保留了原始磁化，由此可以推导出强大的磁极性地层学。也有许多火山矿床含有跨越临界层段的原生火山锆石。这些将用于获得高精度的年龄，以建立一个仔细的年表。综合这些数据，可以评估二叠纪-三叠纪过渡期间发生的环境和生态系统变化。研究成果将被整合到各参与院校的课程中，并将为高中科学教师提供暑期拓展项目。将为菲尔德博物馆获奖的YouTube频道“the Brain Scoop”开发五个教育视频。分析和模型结果的数据可视化将与加州科学院的可视化工作室一起开发，用于非正式教育推广。

ABSTRACTA non-technical description explaining the broader significance of the projectMajor mass extinctions have occurred at various times throughout Earth history. The most well-known of these happened with the demise of the dinosaurs at the end of the Cretaceous Period, but it is believed that the largest mass extinction happened at the end of the Permian Period, approximately 252 million years ago. The extinction in the marine realm was global and occurred over a relatively short time interval. However, events in the terrestrial environment are only sparsely documented. This project will examine well-exposed sedimentary rock successions that formed in lakes, rivers, and ancient soils during the time of these extinctions. This research will enable a precise documentation of the sequence of events on land, a comprehensive analysis of the environmental changes that took place before, during and after the event, and an investigation of how terrestrial animals and plants responded to these changes. The results will determine if extinctions on the continents occurred at the same time as those in the ocean and what conditions existed that may have caused such large-scale changes. Given current concern about rates of extinction, knowledge of the processes that occurred in the past will help identify the reasons behind major changes in flora and fauna. The project will develop museum exhibits and outreach programs to inform both educational and general audiences.A technical description of the projectA comprehensive, multidisciplinary investigation of critical intervals of Earth history offers the best insights into the conditions that prevailed before, during, and after major biotic crises. The Permo-Triassic Mass Extinction is used as a model of how biological and physical systems responded to major climate changes, including those attributable to increasing greenhouse gases. Currently, the Permo-Triassic Mass Extinction is interpreted as a coupled catastrophic collapse of marine and terrestrial ecosystems, both of which experienced protracted restructuring of ecological communities and recovery of stable ecosystem dynamics. The Bogda Mountains in China contain a fully continental stratigraphy spanning the critical interval wherein fluvial and lacustrine deposits alternate with an extensive paleosol record, from which pedogenic trends and geochemical models can be derived. A paleontological record including major plant and animal groups is well-preserved. Pilot-project data show the preservation of a primary magnetization in rocks in the section, from which a robust magnetic polarity stratigraphy can be derived. There are also numerous volcanic deposits that contain primary volcanic zircons spanning the critical interval. These will be used to obtain high precision ages to establish a careful chronology. Together, these data allow evaluation of environmental and ecosystem changes that took place during the Permian-Triassic transition. Research results will be integrated into curricula at each participating academic institution, and summer outreach programs will be offered to high-school science teachers. Five educational videos will be developed for the Field Museum's award winning "The Brain Scoop" YouTube channel. Data visualizations of analytical and model results will be developed for informal education outreach in conjunction with the Visualization Studio at the California Academy of Sciences.