Convergence accommodation and kinematics in orogenic systems

造山系统中的收敛调节和运动学

• 批准号: RGPIN-2016-06736
• 负责人: Larson, Kyle
• 金额: $ 2.4万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684612
• 关键词: Convergence; accommodation; kinematics; orogenic; systems

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.**

过去 15 年，我们对山地带演化的认识取得了重大进展。这些进展大部分来自在喜马拉雅山进行的工作，研究人员开发了热机械模型，用于解释暴露在其中的挖掘出的中地壳岩石的演化。在测试这些模型做出的地质预测时，通过在挖掘出的中地壳上构建详细的压力-温度-时间（变形）路径，发现了一系列神秘的断层结构，并且现已在沿长度的不同位置进行了识别山脉的。这种结构的出现表明，挖出的喜马拉雅中地壳有着更复杂的历史，其内部水平缩短和垂直增厚比之前认识的要明显得多。由于这些断层结构只是最近才发现的，因此关于其地质特征及其在喜马拉雅山运动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脉内部组装模型产生了疑问，这些模型主要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，将在跨越一系列地质时期（新生代至太古代）和造山类型（大陆-大陆）的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，包括详细的现场工作和实验室分析。到增生）。喜马拉雅山、加拿大科迪勒拉山和萨斯喀彻温省北部的研究区域将提供比较不同地质时期中下地壳内神秘结构演化的方法，并为新的全球相关框架提供基础，以了解我们目前的山脉构建范式。**