Thermochronologic Constraints on the Formation of the Transantarctic Mountains, Antarctica

南极洲横贯南极山脉形成的热年代学限制

• 批准号: 9316720
• 负责人: Paul Fitzgerald
• 金额: $ 28.62万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1998-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316720&HistoricalAwards=false
• 关键词: Thermochronologic; Constraints; Formation; Transantarctic; Mountains

9315831 Fitzgerald This award supports a study of the thermal evolution of the Shackleton Glacier region of the Transantarctic Mountains using fission track and 40Ar/39Ar thermochronology. The goal is to use the thermal history of the rocks (temperature-time data that dates the time of cooling) to infer the timing and rate of uplift and denudation of the region. This information will, in turn, allow constraints on mechanistic models for uplift of the range on the southwestern edge of the Ross Embayment. The first year of the award will be used to analyze rocks from existing collections and to prepare for field work in the second year. The Shackleton Glacier region is the focus of new field work because it represents a substantial crustal block that is between two segments of the Transantarctic Mountains which have already been extensively studied. The sampling strategy is to collect vertical profiles from basement rocks at regular intervals across, and along the length of, the Transantarctic Mountains. This strategy minimizes the potential for complications and ambiguities which can result from unmapped faults in the region and maximizes the potential for a good estimate of the cooling history. This new field work will test the hypothesis that the Transantarctic Mountains is segmented, with each segment having a distinct uplift history. The data on the time of cooling at each of several vertical profiles is basic information on the geologic development of the region. These data will be used to infer the uplift and denudation history for each locality. The geographic patterns that emerge will help to constrain the tectonic evolution of the central Transantarctic Mountains and they will place constraints on a diversity of geologic problems from Gondwana breakup and development of the Ross Embayment to development of the Cenozoic ice sheets of Antarctica. ***

9315831 Fitzgerald 该奖项支持利用裂变径迹和 40Ar/39Ar 热年代学对横贯南极山脉沙克尔顿冰川地区的热演化进行研究。 目标是利用岩石的热历史（确定冷却时间的温度-时间数据）来推断该地区隆起和剥蚀的时间和速率。 反过来，这些信息将允许对罗斯海湾西南边缘范围抬升的机械模型进行限制。 该奖项的第一年将用于分析现有收藏中的岩石，并为第二年的实地工作做准备。 沙克尔顿冰川地区是新的实地工作的焦点，因为它代表了横贯南极山脉两段之间的一个巨大的地壳块，这两个部分已经被广泛研究。 采样策略是沿着横贯南极山脉的长度，定期收集基底岩石的垂直剖面。 该策略最大限度地减少了该地区未绘制断层可能导致的复杂性和模糊性的可能性，并最大限度地提高了对冷却历史进行良好估计的潜力。 这项新的实地工作将检验横贯南极山脉是分段的假设，每个分段都有独特的隆升历史。 多个垂直剖面的冷却时间数据是该地区地质发育的基本信息。 这些数据将用于推断每个地点的隆起和剥蚀历史。 出现的地理格局将有助于制约横贯南极中部山脉的构造演化，并将制约从冈瓦纳大陆的分裂和罗斯海湾的发展到南极洲新生代冰盖的发展等各种地质问题。 ***