Transport times and ages of Quaternary fine-grained terrestrial sediments using U series isotopes

该项目将评估碎屑沉积物的铀同位素比率，以衡量基岩通过风化作用变成小颗粒，然后作为沉积物迁移和沉积所需的时间。该方法可能会开辟新的方法来研究和理解沉积物，产生它们的过程，以及沉积过程如何依赖于气候和构造。对来自控制良好的环境的天然沉积物进行详细的物理和化学表征将与同位素测量相结合。野外工作包括从湖泊、黄土沉积物、溪流和冲积扇中收集陆地沉积物样品。这项工作的目的是进一步评估的方法，也调查的沉积物输运时间的变化作为气候和沉积环境的函数。铀系列同位素和宇宙成因核素（Be-10和Al-26）的组合可能会产生有关土壤生成、侵蚀、运输和储存时间尺度的信息，并可能允许对重要类型的大陆沉积物进行定年。学术价值：这项研究将有助于了解沉积学和景观演变的基本方面。该项目负责人有28年的地球化学研究经验，大量发表论文，并拥有20多个博士学位。学生谁去了成功的职业生涯inacademic，政府和私营企业。U.C.伯克利分校有一个长期的记录，支持先进的科学研究，并提供充足的设施，支持人员，和基础设施的研究和研究生教育。更广泛的影响：这项研究对地质和环境研究具有广泛的适用性。它需要质谱、分析和核化学方面的知识和培训，因此是高等教育的绝佳场所。这笔资金将帮助支持一个研究机构，在过去的15年里，该机构已使22名研究生（10名女性）、10名博士后研究员（5名女性）以及20多名访问者、本科生和合作者受益。

This project will evaluate uranium isotope ratios of clastic sediments as a measure of thetime required for bedrock to be reduced to small grains by weathering, and thentransported and deposited as sediment. The method may open up new ways of studying andunderstanding sediments, the processes that produce them, and how sedimentary processesare dependent on climate and tectonics. Detailed physical and chemical characterizationof natural sediment from well-controlled environments will be combined with isotopicmeasurements. Fieldwork consists of collecting samples of terrestrial sediment fromlakes, loess deposits, streams, and alluvial fans. The work is designed to furtherevaluate the approach and also investigate variations in sediment transport time as afunction of climate and depositional environment. The combination of U-series isotopesand cosmogenic nuclides (Be-10 and Al-26) may yield information about timescales of soilgeneration, erosion, transport, and storage, and may allow important types of continentalsedimentary deposits to be dated. Intellectual merit: The research will contribute tounderstanding of fundamental aspects of sedimentology and landscape evolution. The PI has28 years experience in geochemical research, an extensive publication record, and hastrained more than twenty Ph.D. students who have gone on to successful careers inacademia, government, and private industry. U.C. Berkeley has a long record of support ofadvanced scientific research, and provides ample facilities, support personnel, andinfrastructure for research and graduate education. Broader Impacts: The research hasbroad applicability to geology and environmental studies. It requires knowledge andtraining in mass spectrometry, analytical and nuclear chemistry, and hence is an excellentvenue for advanced education. The funding will help support a research facility that, inthe previous 15 years, has benefited 22 graduate students (10 women) 10 postdoctoralfellows (5 women), plus more than 20 visitors, undergraduates and collaborators.