Collaborative Research: Kinematics and Timing of Early Paleozoic Tectonic Events In the Easternmost Precordillera Terrane, Argentina:An Evaluation of Gondwana-Laurentia Interaction

合作研究：阿根廷最东部Precordillera地体早古生代构造事件的运动学和时间：冈瓦纳-劳伦大陆相互作用的评估

• 批准号: 0126299
• 负责人: William McClelland
• 金额: $ 14.97万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0126299&HistoricalAwards=false
• 关键词: Collaborative; Research; Kinematics; Timing; Early

One of the major recent advances in reconstructing past plate configurations was the recognition that the Precordillera Terrane of Argentina was derived (rifted from) the Ouachita embayment of present day North America, thus providing a rare example of knowing exactly where an exotic terrane came from. However, the timing of the rifting and the timing of the subsequent collision with Gondwana, critical to Paleozoic reconstructions is problematic. Previously the timing of the collision was thought to Middle to Late Ordovician based on when the carbonate platform drowned, presumably by close approach and subduction of the continental margin. However, more recent work suggests that the drowning of the carbonate platform was due to rift-related subsidence, and if correct, dates the rifting from North America, not the subsequent collision with Gondwana. This project aims to date the collision by radiometric methods from rocks in the exposed suture zone, including magmatic bodies that intruded during and after the several phases or pulses of collision-related deformation. Results will clarify the arrival time of the Precordillera, data that will be critical in establishing a Paleozoic plate position history.

重建过去板块结构的一个主要进展是认识到阿根廷的前心迪勒拉地体是从现在北美的瓦希塔湾（英语：Ouachita embayment）衍生出来的，从而提供了一个罕见的例子，确切地知道一个外来的岩石来自哪里。然而，裂谷的时间和随后与冈瓦纳大陆碰撞的时间，对古生代重建至关重要，是有问题的。以前，碰撞的时间被认为是中晚奥陶世的基础上，当碳酸盐台地淹没，大概是近距离的方法和大陆边缘的俯冲。然而，最近的研究表明，碳酸盐岩台地的淹没是由于裂谷相关的沉降，如果正确的话，则是来自北美的裂谷，而不是随后与冈瓦纳的碰撞。该项目的目的是通过放射性测量方法，从暴露的缝合带的岩石，包括在碰撞相关变形的几个阶段或脉冲期间和之后侵入的岩浆体，确定碰撞的日期。研究结果将澄清前心脏的到达时间，这些数据将是建立古生代板块位置历史的关键。