Determining Exposure Ages and Erosion Rates of Bedrock Surfaces in Antartic

确定南极基岩表面的暴露年龄和侵蚀率

• 批准号: 8917581
• 负责人: Roy Middleton
• 金额: $ 15.96万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8917581&HistoricalAwards=false
• 关键词: Determining; Exposure; Ages; Erosion; Rates

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.

通过加速器质谱法 (AMS) 测定暴露基岩表面上的宇宙放射性核素浓度，可以提供有关这些表面的暴露时间和侵蚀速率的指导性数据。 多种表面的暴露年龄已确定为 10,000 至 5,000,000 年；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。 研究的目标是： 1) 将样品制备技术改进到能够代表从各种矿物成分样品中有效提取石英的通用、系统程序的水平； 2) 测量合作者提供的南极基岩样本中宇宙成因放射性核素的浓度，并根据暴露年龄、侵蚀率和第四纪冰川历史来解释这些测量结果； 3) 在南极洲收集更多样本以确定暴露年龄和侵蚀率。