Rheological behaviour of the crust

西不列颠哥伦比亚省是由洋壳的持续俯冲在边缘附近产生岩浆岩（类似于今天太平洋板块在西科迪勒拉之下的俯冲以及随后在北美边缘上的火山堆积）以及大岩石碎片（“碎屑”）向边缘的堆积而形成的。一般来说，当断层碰撞时，大部分位移都被相对狭窄的高应变区所吸收，例如圣安德烈亚斯断层。 该建议的目的有两个：（1）对岩石在这些狭窄区域中如何变形的机制施加约束，以确定这些区域的寿命，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，并了解容纳不列颠哥伦比亚省中西部碰撞的机制。这项拟议的研究结合了在碰撞机制中发现的变形岩石的现场测绘，从现场收集的岩石的显微结构分析，以及地质年代学（对岩石进行测年），以更好地了解岩石如何在高应变区变形的机制。该提案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中发生的过程。

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.