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: 0126198
• 负责人: Sarah Roeske
• 金额: $ 13.32万
• 依托单位: University of California-Davis
• 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=0126198&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.

重建过去板配置的最新进展之一是认识到，阿根廷的precordillera地座是从当今北美的瓦希塔（Ouachita）埋入的（从）衍生而来的，因此提供了一个罕见的例子，证明了一个准确地知道异国情调的地形。但是，裂谷的时机和随后与冈瓦纳的碰撞的时机，至关重要的古生代重建是有问题的。以前，碰撞的时机被认为是基于碳酸盐平台淹没的何时在中后期的，大概是通过近距离接近和大陆边缘的俯冲来淹没的。但是，最近的工作表明，碳酸盐平台的溺水是由于与裂谷相关的沉降造成的，如果正确，则可以追溯到北美的裂缝，而不是随后与冈瓦纳的碰撞。该项目的目的是通过裸露缝合区中岩石的辐射方法发生碰撞，包括在几个阶段和碰撞相关变形的几个阶段或脉冲之后侵入的岩浆体。结果将阐明precordillera的到达时间，这对于建立古生代板位历史记录至关重要。