A Combined Structural-Petrological Analysis of the Origin and Role of Partial Melting in Orogens

造山带部分熔融的起源和作用的构造-岩石学联合分析

• 批准号: 9814669
• 负责人: Christian Teyssier
• 金额: $ 21.32万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814669&HistoricalAwards=false
• 关键词: Combined; Structural; Petrological; Analysis; Origin

9814669Teyssier Partial melting in the core of orogens likely controls the rheology of the crust subsequent to crustal thickening. Geophysical observations suggest that the deep crust under active orogens, such as southern Tibet, is decoupled from the lithospheric mantle and the rigid upper crust. This deep crust probably has a low viscosity and is able to flow. This project is aimed at providing an observational database to these conceptual geodynamic models by study of migmatites associated with the Shuswap metamorphic core complex in the Canadian Cordillera. The work will determine the P-T time paths of the metamorphic rocks, locate partial melting on this path and determine pressure of emplacement. Textural and petrologic analysis will constrain the conditions of partial melting and will determine flow of the partially mullen crust from shape preferred orientations of minerals. Results will be useful in testing and refining models of orogenic collapse and extension.***

小行星9814669 造山带核部的部分熔融可能控制着地壳增厚后的地壳流变学。 地球物理观测表明，活动造山带下的地壳深部，如藏南，与岩石圈地幔和刚性上地壳是解耦的。 这种深层地壳可能具有低粘度，并且能够流动。 该项目旨在通过研究与加拿大科迪勒拉Shuswap变质核杂岩有关的混合岩，为这些概念性地球动力学模型提供观测数据库。 确定了变质岩的P-T时间轨迹，并在该轨迹上定位了部分熔融，确定了侵位压力。 结构和岩石学分析将限制部分熔融的条件，并将从矿物的形状优选取向确定部分马伦地壳的流动。 研究结果将有助于检验和完善造山带塌陷和伸展的模型。