GOALI: MCA: Insights to Critical Zone Dynamics During Icehouse Deglaciation: Piloting a Late Paleozoic Climate Observatory

随着当前气候从较冷的冰期转向较暖的去冰期，了解包括河流、土壤和森林在内的陆地景观如何应对这种变化是很重要的。地球上一次走出冰期发生在大约2.85亿年前的晚古生代冰期（LPIA）末期。现有的一些研究表明，LPIA森林主要在冰川消退期间的气候变暖条件下迅速生长和扩张。然而，其他研究表明，在冰期期间，森林变得更小，生长更少，相反，森林扩张主要发生在冰期较冷的气候条件下。为了确定LPIA气候对陆地和“关键带”（如土壤层）条件的影响，包括温度、降水和大气中的碳去除（如泥炭埋藏、土壤风化、土壤碳沉积），该项目将使用年龄测年、同位素地球化学和尖端自动化矿物学技术分析西弗吉尼亚州和捷克共和国的沉积物。此外，该项目还将支持与Bruker公司的学术行业合作，这将加速沉积地质领域的自动化矿物学应用。最后，该项目将支持社区驱动的晚古生代气候观测站的发展，并为西弗吉尼亚州的本科生、研究生研究人员、6-12年级学生和中学教育工作者提供STEM教育机会。这项工作的结果将解决LPIA煤林动力学冲突模型中固有的3个主要问题：1)偏心率驱动的气候振荡是否在热带盘古大陆形成相关的陆地周期？2) LPIA冰期是否与热带高原干旱或湿润气候有关？3)陆地系统如何响应LPIA极端气候？这些问题的答案将通过整合多代地质年代学（U-Pb碎屑磷灰石、Re-Os）、碳酸盐结核古大气测量和古温学、欧西化学地层学、河流古水文和多尺度古岩石矿物学表征、沉积物物源、碳酸盐结核组成/成岩作用来实现。这些结果将检验一个假设，即热带泥炭林的发展主要发生在冰川时期，因为在潮湿的气候条件下，地下水位升高。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

As the current climate shifts from a cooler glacial episode into a warmer deglacial episode, it is important to understand how terrestrial landscapes, including rivers, soils and forests, may respond to this change. The last time Earth’s climate shifted out of an Ice Age occurred ~285 million years ago at the end of the Late Paleozoic Ice Age (LPIA). Some existing research suggests LPIA forests grew rapidly and expanded mainly under warming climate conditions during deglaciation. However, other research suggests forests became smaller and experienced less growth during deglaciation episodes, and instead forest expansion occurred mainly during the cooler climate conditions of glacial episodes. In order to determine the influence of LPIA climate on terrestrial and “critical zone” (e.g., soil horizon) conditions, including temperature, precipitation and carbon removal from the atmosphere (e.g., peat burial, soil weathering, soil carbon deposition), this project will analyze deposits in West Virginia and the Czech Republic using age dating, isotope geochemistry and cutting-edge automated mineralogy technologies. Additionally, the project will support an academic-industry collaboration with Bruker Inc. that will accelerate automated mineralogy applications to the field of sedimentary geology. Finally, this project will support development of a community-driven Late Paleozoic Climate Observatory, and provide STEM educational opportunities for undergraduates, graduate researchers, grade 6-12 students and secondary educators in West Virginia.Results from this work will resolve 3 major questions inherent in the conflicting models of LPIA coal forest dynamics: 1) Did eccentricity-driven climatic oscillations form correlatable terrestrial cyclothems across tropical Pangea?; 2) Were LPIA glaciations associated with arid or humid climate in tropical uplands?; and 3) How did terrestrial systems respond to LPIA climate extremes? Answers to these questions will be achieved through integration of multi-proxy geochronology (U-Pb detrital apatite, Re-Os), carbonate nodule paleobarometry and paleothermometry, Osi chemostratigraphy, fluvial paleohydrology and multi-scale mineralogical characterization of paleopedology, sediment provenance, and carbonate nodule composition/diagenesis. These results will test the hypothesis that tropical peat forest development occurred mainly during glacial episodes due to elevated groundwater tables during ever-wet, climate conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.