Convergence accommodation and kinematics in orogenic systems

在过去的15年里，我们对山地带如何演变的认识取得了重大进展。这一进展大部分来自在喜马拉雅开展的工作，研究人员在那里开发了暴露于其中的中地壳岩石演化的热机械模型。在测试这些模型所作的地质预测时，通过建造穿越挖出的中地壳的详细的压力-温度-时间（-变形）路径，发现了一系列隐蔽的断层结构，现在已在沿着山脉的不同地点查明。这种结构的发生表明了一个更复杂的历史，喜马拉雅中地壳的挖出显着更多的内部水平缩短和垂直增厚比以前认识到的。由于这些断层构造是最近才发现的，关于它们的地质特征及其在喜马拉雅运动学演化中的总体作用的数据很少。此外，这些结构的存在使人们对以前的山区带内部组装模型提出了质疑，这些模型在很大程度上是基于喜马拉雅山的数据。拟议的研究旨在了解碰撞事件期间活跃的过程以及这些新认识的结构可能发挥的作用。为了实现这一目标，将在三个目标区域的神秘断层结构上进行全面、综合的地质调查，包括详细的实地工作和实验室分析，这些目标区域跨越一系列地质时代（新生代到太古代）和造山类型（大陆-大陆到增生）。喜马拉雅山，加拿大科迪勒拉，和北方萨斯喀彻温省的研究领域将提供的手段来比较的中地壳到下地壳的整个地质时期的神秘结构的演变，并提供了一个新的全球相关的框架，以告知我们目前的造山模式的基础。

The past 15 years have seen major advances in our knowledge of how mountain belts evolve. Much of this progress has come from work carried out in the Himalaya where researchers have developed thermo-mechanical models for the evolution of the exhumed midcrustal rocks exposed therein. While testing geologic predictions made by these models, through the construction of detailed pressure-temperature-time(-deformation) paths across the exhumed mid-crust, a series of cryptic fault structures were discovered and have now been identified in various locations along the length of the mountain chain. The occurrence of such structures indicates a more complex history for the exhumed Himalayan mid-crust with significantly more internal horizontal shortening and vertical thickening than previously recognized. Because these fault structures are only recent discoveries, little data exist on their geologic characteristics and their overall role in the kinematic evolution of the Himalaya. Moreover, the existence of these structures calls into question previous models for the assembly of the interior of mountain belts, which have been largely based on data from the Himalaya. The proposed research aims to understand the processes active during collisional events and the role that these newly recognised structures may have played. To meet this goal, comprehensive, integrative geologic investigations, including detailed field work and laboratory analysis, will be carried out across enigmatic fault structures in three targeted areas that span a range of geologic time (Cenozoic to Archean) and orogenic types (continent-continent to accretionary). Study areas in the Himalaya, the Canadian Cordillera, and northern Saskatchewan will provide the means to compare the evolution of cryptic structures within the mid-to-lower crust across geologic time and provide the basis for a new globally relevant framework to inform our present mountain building paradigm.