Rheological behaviour of the crust

不列颠哥伦比亚省西部是由洋壳持续俯冲，在边缘附近形成岩浆岩(类似于今天科迪勒拉西部之下的太平洋板块俯冲并随后在北美边缘形成火山所发生的情况)和大量岩石碎片(地体)向边缘聚集而形成的。一般来说，当地体碰撞时，大部分位移被相对较窄的高应变带--例如圣安德烈亚斯断层--占据。这项建议的目的有两个：(1)对这些狭窄带中岩石如何变形的机制施加限制，确定这些带的寿命，并确定这些剪切带的范围和几何形状，以及(2)施加更好的时间约束，并了解不列颠哥伦比亚省中西部发生碰撞的机制。这项拟议的研究结合了在碰撞制度中发现的变形岩石的现场测绘，以及从现场收集的岩石的微观结构分析，以及地质年代学(岩石测年)，以更好地了解高应变区岩石变形的机制。这项提议的一个较小的方面涉及实验岩石变形，以及我们如何使用从实验室收集的应力-应变数据来更好地了解地球上发生的过程。

Western British Columbia was constructed by continued subduction of oceanic crust creating magmatic rocks near the margin (similar to what is happening today with the subduction of the Pacific plate beneath the western Cordillera and the consequent build up of volcanoes on the north American margin) and by the accretion of large fragments of rock ('terranes') to the margin. Generally, when terranes collide much of the displacement is taken up by relatively narrow zones of very high strain - consider, for example, the San Andreas Fault.  The purpose of this proposal is twofold: (1) To place constraints on the mechanisms of how rocks deform in these narrow zones, to determine how long-lived these zones are, and to determine the extent and geometry of these shear zones, and  (2) to place better timing constraints and understand the mechanisms that accommodated collision in west central British Columbia. This proposed research combines field mapping of deformed rocks found in collisional regimes, with microstructural analysis of rocks collected from the field, with geochronology (dating the rocks) to better understand the mechanisms of how rocks deform in zones of high strain. A smaller aspect of this proposal deals with experimental rock deformation and how we can use stress-strain data collected from the lab to better understand processes that occur in the Earth.