DEVELOPING A PROCESS-BASED UNDERSTANDING OF THE FACTORS CONTROLLING THE SEASONAL FORMATION OF PEDOGENIC CARBONATE

蒂莫西·M·加拉格尔博士获得了NSF EAR博士后奖学金，在德克萨斯大学奥斯汀分校开展研究和教育计划。调查的重点将是了解土壤中碳酸盐矿物的季节性形成。该项目将由三个部分组成：实验室实验，计算机模拟，以及将实验和模拟结果应用于地质问题。预期的结果将引起包括地球科学、生物科学和土壤科学在内的广泛学科的兴趣。在整个研究金期间，加拉格尔博士将通过参加德克萨斯大学K-12面向40英亩的节日等活动，积极向公众传达环境变化的重要性。此外，他还将指导研究生，开发和监督本科生的独立研究项目。加拉格尔博士将联合教授一门本科生环境同位素地球化学课程，开发新的作业，旨在让学生接触到计算机建模的能力和实用性。研究项目将采用将实验土壤操纵与尖端反应迁移建模相结合的新方法，以彻底了解驱动土壤成因碳酸盐形成的过程。研究计划将包括(1)模拟不同季节降水模式的土柱实验操作，(2)使用反应运移模型将研究的实验结果置于定量和预测框架中，以及(3)将实验和模拟结果应用于以土壤成因碳酸盐为中心的地质学案例研究中，以安第斯隆起的古高程历史为中心。土壤中的碳酸盐矿物是过去环境条件的重要档案，被科学界广泛用于恢复过去的气候、生态和构造变化。这些古重建的准确性受到了阻碍，这在很大程度上是因为控制成壤碳酸盐形成季节时间的过程还没有得到充分的表征。预计这项调查将有助于这一知识差距。

Dr. Timothy M. Gallagher has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at the University of Texas at Austin. The investigation will focus on understanding the seasonal formation of carbonate minerals in soils. The project will consist of three components: laboratory experiments, computer modeling, and application of experimental and modeling results to a geological problem. The anticipated results will be of interest to a wide range of disciplines including those within the earth, biological, and soil sciences. Throughout this fellowship period Dr. Gallagher will actively convey the importance of environmental change to the general public through participation in events such as the University of Texas K-12 oriented Forty Acres Fest. In addition, he will mentor graduate students and develop and supervise independent research projects for undergraduates. Dr. Gallagher will co-teach an undergraduate environmental isotope geochemistry course, developing new assignments designed to expose students to the power and utility of computer modeling.The research project will take the novel approach of pairing experimental soil manipulations with cutting-edge reactive transport modeling in order to gain a thorough understanding of processes drivingpedogenic carbonate formation. The research plan will include (1) experimental manipulation of soil columns where different seasonal patterns of precipitation are simulated, (2) use of reactive transport models to place the experimental results of the research into a quantitative and predictive framework, and (3) application of the experimental and modeling results to a geologic case study centered on pedogenic carbonate derived paleoelevation histories of Andean uplift. Carbonate minerals in soils are an important archive of past environmental conditions, that is widely used by the scientific community for reconstructing past climatological, ecological and tectonic changes. The accuracy of these paleo-reconstructions is hindered, in large part because the processes controlling the seasonal timing of pedogenic carbonate formation have not been fully characterized. It is expected that this investigation will contribute to this knowledge gap.