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

0001092 Tikoff 0003007 McClelland造山带的构造模型依赖于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”和剪切方向等。 一个基本的假设是，构造运输方向平行矿物或延伸线理方向，但三维数值模拟的剪切带表明，这并不总是一个有效的假设。 本项目将利用爱达荷州西部剪切带来解决这一问题，该剪切带标志着晚白垩世期间北美板块西部的外来碎屑物的增生。 运动学和地质学数据已经导致了几个不同的模型，这种增生。 这项研究是一个综合的结构，显微构造和U/Pb地质年代学项目，旨在确定晚白垩世西部爱达荷州剪切带的运动历史，将采用三维技术来测试构造运输平行于线理假设的有效性。 结果应有助于澄清运动学的缝合线，并评估一个重要的运动学假设，用于解释许多造山带在其他地方。

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.