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)提供资金的。该提案寻求有限的资金，以充分利用2007/2008年度南极干旱山谷野外季节收集的样本和数据。干旱山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1500万年前。尽管这些推断的年龄与东南极冰盖的长期稳定性有关，但具体的景观改变机制和速度并没有得到很好的限制。冰冻扰动(通常被认为是有图案的地面)是冰缘环境中主要的景观修改剂之一。该项目的工作重点将是利用实地样品的地质年代学与激光雷达地貌特征相结合的方法直接确定低温扰动率和机制。宇宙成因的3He测量将在灯塔谷和晨峰的深度剖面和表面样品上完成。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。宇宙源核素测量是拟议项目中最耗费人力的部分。

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.