EAR-PF Paleoelevation reconstruction in hyper-arid settings – integrating triple oxygen and clumped isotope techniques in the Salar de Atacama Basin, Chile (22-25S)

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。克里斯蒂娜·L·巴特勒被授予NSF EAR博士后奖学金，在华盛顿大学和布朗大学开展与气候和造山有关的研究和教育活动。通过造山建造高海拔对全球和当地气候、区域河流和地下水系统以及物种多样性产生了巨大影响。记录建造高海拔地区的时间和速度是将重要的地球系统过程彼此联系起来的关键。然而，高海拔地区也往往是地球上最干燥的地区之一，这给重建地表隆起的历史带来了挑战。传统的方法很容易在温带和热带气候下使用，但由于蒸发的影响，在干旱的沙漠地区可能不那么有效。该项目使用最近开发的技术来重建湖泊碳酸盐的表面高程发展，这记录了南美洲中部安第斯山脉的造山历史。这项研究聚焦于地球上最干旱的地区之一--萨拉德阿塔卡马沙漠，有可能展示如何将新的新兴技术应用于地球科学中长期存在的问题。该项目将为来自美国和南美洲传统上缺乏服务的社区的地球科学本科生提供实地和实验室培训和研究机会。准确重建地表高程历史仍然是地球科学家面临的关键挑战，特别是在极度干旱的地区，蒸发的影响导致使用传统的基于δ18O的方法对古温度和古海拔的估计不准确。新出现的三重氧同位素技术有望限制高干旱内河环境中碳酸盐母水固有的δ18O值的蒸发富集度。首席研究员克里斯蒂娜·巴特勒将与布朗大学和华盛顿大学的科学顾问合作，将这种新的稳定同位素方法应用于古海拔重建(Δ17O-δ18O)，并辅之以基于温度的古高程测量(Δ47)。这些相辅相成的方法将被用来记录中央安第斯山脉高地的发展。该项目的目标是通过整合沉积学、地质年代学和稳定同位素技术，重建萨拉德阿塔卡马沙漠的中新世到最近的地表高程历史，最终目标是确定高地形的驱动机制，并解决中央安第斯地区相互冲突的地表高程记录。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智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Dr. Kristina L. Butler has been awarded an NSF EAR Postdoctoral Fellowship to carry out research and education activities related to climate and mountain building at the University of Washington and Brown University. The construction of high elevations through mountain building dramatically influences global and local climate, regional river and groundwater systems, and species diversification. Documenting the timing and rate at which regions of high elevation were built is key to connecting important Earth system processes to one another. However, regions of high elevation also tend to be some of the driest localities on Earth, which creates challenges in reconstructing the history of surface uplift. Traditional methods, used easily in temperate and tropical climates, can be less effective in dry, desert-like regions due the effect of evaporation. This project uses recently developed techniques to reconstruct surface elevation development from lacustrine carbonates, which record the history of mountain building in the Central Andes, South America. Focusing on one of the driest regions on Earth, the Salar de Atacama Desert, this study has the potential to demonstrate how new, emerging techniques can be applied to longstanding questions in Earth Science. The project will support field- and laboratory-based training and research opportunities for geoscience undergraduate students from traditionally underserved communities in both the United States and South America. Accurate reconstruction of surface elevation histories remains a key challenge for Earth scientists, especially in regions of hyper-arid conditions where the effects of evaporation lead to inaccurate estimation of paleotemperature and paleoelevation using conventional δ 18O-based methods. Emerging triple oxygen isotope techniques show promise in constraining the degree of evaporative enrichment of δ 18O values of carbonate parent water inherent to lacustrine systems in hyper-arid endorheic settings. Principle investigator Kristina Butler will apply this new stable isotope methodology for paleoelevation reconstruction (Δ17O- δ 18O) complimented by temperature-based paleoaltimetry (Δ47) in collaboration with scientific advisers at Brown University and University of Washington. These complimentary methods will be used to document the development of high topography in the Central Andes. The objective of the project is to reconstruct the Miocene to recent surface elevation history in the Salar de Atacama Desert by integrating sedimentology, geochronology, and stable isotope techniques with the ultimate goal of defining the driving mechanisms for high topography and resolving conflicting surface elevation records in the Central Andes.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.