Determining Exposure Ages and Erosion Rates of Bedrock Surfaces in Antartic

用加速器质谱法测定暴露的基岩表面上的宇宙形成放射性核素浓度，提供了关于这些表面的暴露时间和侵蚀速率的指标性数据。已经确定了各种各样的表面的暴露年龄从1万年到500万年不等；迄今为止报道的最古老的暴露时间是在南极大陆的基岩样本上测量的。本研究的目标是：1)改进样品制备技术，使其能够代表一种通用的、系统的程序，从各种矿物组成的样品中有效地提取石英；2)测量合作者提供的南极基岩样品中宇宙成因放射性核素的浓度，并根据暴露年龄、侵蚀速率和第四纪冰川历史来解释这些测量结果；3)在南极洲进一步收集样品，以确定暴露年龄和侵蚀速率。

Determination by Accelerator Mass Spectrometry (AMS) of concentrations of the cosmogenic radionuclides on exposed bedrock surfaces provides instructive data on exposure times and rates of erosion for those surfaces. Exposure ages ranging from 10,000 to 5,000,000 years have been determined for a wide variety of surfaces; the oldest exposure times yet reported have been measured on bedrock samples from the Antarctic continent. The goals of the research are: 1) to refine sample-preparation technique to the level that it will represent a generalized, systematic procedure to extract quartz efficiently from samples of a wide range of mineral composition; 2) to measure concentrations of cosmogenic radionuclides in Antarctic bedrock samples provided by collaborators, and to interpret those measurements in terms of exposure ages, erosion rates, and Quaternary glacial history; and 3) to collect further sample in Antarctica for determination of exposure ages and erosion rates.