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川期转变为较暖的冰消期，了解包括河流、土壤和森林在内的陆地景观如何应对这一变化至关重要。上一次地球气候从冰河时代转变出来发生在大约2.85亿年前的晚古生代冰河时代（LPIA）结束时。一些现有的研究表明，LPIA森林生长迅速，主要是在冰川消退期间气候变暖的条件下扩大。然而，其他研究表明，在冰川消退期间，森林变得更小，增长更少，相反，森林扩张主要发生在冰川期较冷的气候条件下。为了确定LPIA气候对陆地和“临界区”（例如，土壤层位）条件，包括温度、降水和从大气中除去碳（例如，该项目将利用年代测定、同位素地球化学和尖端自动矿物学技术分析西弗吉尼亚州和捷克共和国的矿床。此外，该项目还将支持与布鲁克公司的学术-工业合作。这将加速自动矿物学在沉积地质学领域的应用。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年级的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煤林动态相互冲突的模型中固有的3个主要问题：1）偏心率驱动的气候振荡是否在热带泛大陆形成了可验证的陆地旋回层？2)LPIA冰川与热带高地的干旱或潮湿气候有关吗？陆地系统对LPIA极端气候的响应？这些问题的答案将通过综合多代用地质年代学（U-Pb碎屑磷灰石、Re-Os）、碳酸盐结核古压力测定法和古温度测定法、Osi化学地层学、河流古水文学以及古土壤学、沉积物来源和碳酸盐结核组成/成岩作用的多尺度矿物学特征来实现。这些结果将测试的假设，热带泥炭森林的发展主要发生在冰川时期，由于地下水位升高，在不断潮湿的气候条件下，这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.