Collaborative Research: Testing Three-Dimensional Kinematic Analysis of Mid-Crustal Ductile Shear Zones: Deformation within the Western Idaho Shear Zone

合作研究：测试中地壳韧性剪切带的三维运动学分析：爱达荷州西部剪切带内的变形

• 批准号: 0003007
• 负责人: William McClelland
• 金额: $ 6.29万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003007&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Three; Dimensional

0001092 Tikoff0003007 McClellandTectonic models for orogenic belts rely on various kinematic indicators to determine such things as maximum and minimum stress directions, "stretching directions" and sense of shear. One fundamental assumption has been that tectonic transport directions parallel mineral or extension lineation directions, however three-dimensional numeric modeling of shear zones indicates that this is not always a valid assumption. This project will address this issue using the western Idaho shear zone that marks the accretion of allochthonous terranes to the west to the north American plate during the Late Cretaceous. The kinematic and geologic data have resulted in several, disparate models for this accretion. This study is an integrated structural, microstructural and U/Pb geochronologic project designed to determine the kinematic history of the late Cretaceous western Idaho shear zone that will employ three-dimensional techniques to test the validity of the assumption that tectonic transport is parallel to lineation. Results should help clarify the kinematics of this suture and evaluate one of the important kinematic assumptions used in interpretations of many orogens elsewhere.

造山带的构造模型依靠各种运动学指标来确定诸如最大和最小应力方向、“拉伸方向”和剪切感等。一个基本假设是构造运输方向与矿物或伸展线理方向平行，然而剪切带的三维数值模拟表明，这并不总是一个有效的假设。该项目将利用爱达荷州西部剪切带来解决这个问题，该剪切带标志着晚白垩纪时期北美板块西部的异域地体的增生。运动学和地质数据已经为这次增生形成了几个不同的模型。本研究是一个综合的构造、微观构造和U/Pb年代学项目，旨在确定晚白垩世西爱达荷剪切带的运动历史，并将采用三维技术来验证构造运输平行于线理的假设的有效性。结果将有助于澄清这条缝合线的运动学，并评估在其他地方解释许多造山带时使用的重要运动学假设之一。