Periglacial Landscape Evolution in Antarctica: New Constraints on Patterned Ground Formation

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该提案寻求有限的资金，以充分利用2007/2008年在南极洲干谷野外季节收集的样本和数据。干谷地区的景观是地球上最古老的景观之一，有些甚至可以追溯到中新世，大约有1500万年的历史。虽然这些推断的年龄与南极东部冰盖的长期稳定性有关；景观改变的具体机制和速率没有得到很好的限制。低温扰动（通常被认为是带状地面）是冰缘环境的主要景观改变因素之一。该项目的工作重点是直接确定低温扰动率和机制，结合现场样品的地质年代学和激光雷达景观特征。宇宙起源的3He测量将在比肯谷和莫宁山的深度剖面和地表样本上完成。虽然重点将放在3He测量上，因为它们可以更快地完成，但21Ne测量也将在选定的样品上进行。宇宙核素的测量是这个计划中劳动强度最大的部分。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The proposal seeks limited funds to exploit fully the samples and data collected during the 2007/2008 field season in Dry Valleys, Antarctica. The landscapes of the Dry Valleys region are among the oldest on Earth, some as old as Miocene, ~15 million years old. Although these inferred ages are relevant to the long-term stability of the East Antarctic Ice Sheet; the specific mechanisms and rates of landscape modification are not well constrained. Cryoturbation (most commonly recognized as patterned ground) is one of the primary landscape modifiers in periglacial environments. This project's effort will be focused to direct determination of cryoturbation rates and mechanisms using a combination of geochronology of field samples combined with the LiDAR landscape characterization. The cosmogenic 3He measurements will be completed on the depth profiles and surficial samples from Beacon Valley and Mount Morning. While the emphasis will be on 3He measurements as they can be done more quickly, the 21Ne measurements will be also undertaken on selected samples. The cosmogenic nuclide measurements are the most labor-intensive component of the proposed project.