U.S.-France Planning Visit: Investigating Upland Glaciation in the Pangaean Tropics

这项国际规划赠款的目的是与法国同事会面并进行实地勘察，调查盘古山脉中部（中央地块地区）沉积岩中的晚古生代古气候，目的是在该主题上开展未来的国际合作。 晚古生代（宾夕法尼亚-二叠纪）记录了地球上所谓“冰室”的最新例子。大气中二氧化碳含量较低，高纬度地区持续存在冰川作用，与地球当前和近期的状态类似。此外，晚古生代（3亿年前）是地球从拥有大片冰盖和高山冰川的行星转变为基本上无冰的行星的最后一个例子。尽管高纬度地区晚古生代冰盖的存在早已被人们所接受，但低纬度地区是否存在冰川作用仍受到质疑。如果热带地区存在冰，那么我们对这段时期地球气候行为的模型就需要修改。该项目源于美国 PI Soreghan 和法国地球科学家的独立工作，研究对象是晚古生代热带地区（即横跨欧洲和北美的低纬度盘古大陆山脉）的冰川作用假说。法国二叠纪-宾夕法尼亚地层高山冰川作用的假说可以追溯到一个世纪前，但直到最近几年才重新出现，这与索雷根在美国的工作相吻合。这项旅行资助将开始一项新的研究合作，以索雷根和法国同事去年偶然的电子邮件往来为基础。该项目将分三个阶段进行，如下：1）初步规划，所有合作者都参与，通过电子邮件和视频会议进行； 2) 策划访问，包括 PI Soreghan 和三名来自俄克拉荷马大学的学生（本科生和研究生）。这次访问将包括在法国机构举行座谈会，然后进行为期一天的实地考察，考察研究地点。 3) 旅行结束后的活动将需要在美国和法国实验室进行数据分析和数据共享，目的是开发一个未来的研究项目，对那些最有希望保存古气候高地记录的地区进行全面评估。 智力价值：如果结果继续表明高地热带盘古大陆有冰川作用，那么这意味着长期接受的盘古大陆气候重建发生了巨大转变。晚古生代冰期是地球最近的前第四纪冰川作用，因此是气候建模者的共同目标，他们使用与预测未来气候相同的模型。因此，对这些模型的校准对于了解地球气候系统的更广泛方面至关重要。 更广泛的影响：合作研究将提高美国和法国合作者的研究技能。计划前往法国进行长期研究项目，将为来自俄勒冈大学的参与的美国学生提供一个绝佳的机会，体验跨学科国际研究合作开始的科学经验，以及在国外参观和开展地质学的文化体验。拟议的研究将有助于所有合作者在沉积学和构造分析方面的经验基础和专业知识，同时开发数据集和结果，以协助许多其他研究人员和研究项目。

The objective of this international planning grant is to meet with French colleagues and conduct a reconnaissance field trip to investigate Late Paleozoic paleoclimate in sedimentary rocks of the Central Pangaean mountains (Massif Central region), with the aim of developing a future international collaboration on this topic. The Late Paleozoic (Pennsylvanian-Permian) records Earth?s most recent example of so-called ?icehouse? conditions, in which atmospheric CO2 levels were low and glaciation persisted at high latitudes, similar to Earth?s current and recent state. Moreover, the Late Paleozoic (300 million years ago) is Earth?s last example of the transition from a planet that hosted large ice sheets and alpine glaciers to one that was essentially ice-free. Although the former existence of Late Paleozoic ice sheets in high-latitude regions has been long accepted, the existence of glaciation at low latitudes is in question; if ice existed in the tropics, then our models for Earth?s climate behavior during this time require revision. This project stems from independent work by PI Soreghan in the U.S., and geoscientists in France, on the hypothesis of glaciation in the Late Paleozoic tropics -- i.e., the mountains of low-latitude Pangaea, which spanned from Europe to North America. The hypothesis of alpine glaciation in the Permo-Pennsylvanian strata of France dates back a century, but has only resurfaced in the last few years, coincident with Soreghan?s work in the U.S. This travel grant is to begin a new research collaboration, building upon incidental email exchanges between Soreghan and French colleagues over the last year. The project will occur in three phases, as follows: 1) initial planning, involving all collaborators, via email and video-conferencing; 2) the planning visit, involving PI Soreghan, and three students from the University of Oklahoma (undergraduate and graduate). This visit will involve colloquia at the French institutions, followed by a day field excursion to canvass research localities. 3) Post-trip activities will entail data analysis in U.S. and French labs, and data sharing with the intent of developing a future research project to undertake a comprehensive assessment of those localities that show the best promise for preserving an upland record of paleoclimate.Intellectual Merit: If results continue to indicate glaciation in upland tropical Pangaea, then this implies an enormous shift in long-accepted reconstructions of Pangaean climate. The Late Paleozoic Ice Age is Earth?s most recent pre-Quaternary glaciation, and thus a common target for climate modelers, using the same models as those employed to predict future climate. Hence, calibrations to these models are critical for understanding broader aspects of Earth?s climate system.Broader Impacts: The collaborative research will enhance the research skills of both U.S. and French collaborators. A planning trip to France, with the promise of a longer-term research project, will afford participating US students from OU an extraordinary opportunity to experience both the scientific experience of inception of an interdisciplinary, international research collaboration, and the cultural experience of visiting and conducting geology in a foreign locale. The proposed research will contribute to the experience base and expertise in sedimentologic and tectonic analyses of all collaborators, while developing datasets and results that will assist a number of other researchers and research projects.