Testing the East Antarctica-Laurentian Connection: Ages of Detrital Zircons from Late Proterozoic Metasediments, Transantarctic Mountains

测试东南极洲-劳伦斯联系：横贯南极山脉晚元古代变沉积岩中碎屑锆石的年龄

• 批准号: 9418621
• 负责人: Nicholas Walker
• 金额: $ 3.05万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-03-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418621&HistoricalAwards=false
• 关键词: Testing; East; Antarctica; Laurentian; Connection

Abstract This award supports a project to test the recent hypothesis that Laurentia (the cratonic part of present-day North America) was adjacent to the East Antarctic craton during late Proterozoic time and was therefore a part of Gondwana. The hypothesized geographic disposition of these continental masses has far-reaching implications for the assembly, evolution, and breakup of Gondwana. This hypothesis, however, has not yet been substantially tested. If Laurentia did breakout of Gondwana from a position adjacent to Antarctica, rift-related sediments should record this event and contain detritus, including detrital zircon, derived from the rifting continent. Late Proterozoic metasedimentary rocks exposed throughout the Transantarctic Mountains (including the La Gorce, Duncan, Goldie, and Cobham Formations, and the Skelton and Koettlitz Groups) are the most-likely candidates for such rocks. This project will produce a geochronometric inventory of detrital zircons from samples of these units distributed along the length of the Transantarctic Mountains. The geochronometric data will provide a useful test of the hypothesis and will complement on-going detrital zircon studies of other Proterozoic rocks in the Transantarctic Range.

摘要 该奖项支持一个项目来检验最近的假设，即劳伦大陆（现今北美的克拉通部分）在元古代晚期毗邻东南极克拉通，因此是冈瓦纳大陆的一部分。 这些大陆块的假设地理分布对冈瓦纳大陆的聚集、演化和分裂具有深远的影响。 然而，这一假设尚未得到实质性检验。 如果劳伦大陆确实从邻近南极洲的位置突破了冈瓦纳大陆，那么与裂谷相关的沉积物应该记录了这一事件，并含有来自裂谷大陆的碎屑，包括碎屑锆石。 横贯南极山脉（包括 La Gorce、Duncan、Goldie 和 Cobham 地层，以及 Skelton 和 Koettlitz 群）中暴露的晚元古代变质沉积岩是此类岩石最有可能的候选者。 该项目将从沿横贯南极山脉分布的这些单元的样本中产生碎屑锆石的地质年代学清单。 地质测时数据将为这一假设提供有用的检验，并将补充正在进行的横贯南极山脉其他元古代岩石的碎屑锆石研究。