Petrological and Tectonic Investigations of High Pressure Metamorphism in NE Oman

阿曼东北部高压变质作用的岩石学和构造研究

• 批准号: 8904821
• 负责人: Robert Coleman
• 金额: $ 4.94万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1992-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904821&HistoricalAwards=false
• 关键词: Petrological; Tectonic; Investigations; Pressure; Metamorphism

Blueschists, type-C eclogites and other high pressure metamorphic rocks occur in the basement and continental platform deposits of the Saih Hatat culmination in northeastern Oman. The blueschists and eclogites constitute a coherent in situ terrain structurally overlain by two thrust piles containing lower-grade high pressure metamorphic assemblages. The entire sequence is overlain by the Semail ophiolite nappe. The tectonic setting of these high pressure metamorphic rocks is unique given their occurrence in a passive continental margin that has not undergone continent-continent collision and their structural relations to the unmetamorphosed Tethyan Semail ophiolite nappe. The NSF is requested to provide two-year support to continue a detailed field, petrological, geochemical and geochronological study of high pressure metamorphism in NE Oman. This study is aimed at (a) constraining the pressure-temperature conditions of metamorphism and reconstructing the pressure-temperature-time paths of the different structural terrains (b) developing petrogenetic grids for the various lithologies of the high pressure metamorphic rocks; and (c) establishing the ages of metamorphism and uplift rates of these domains. The results of this study will constrain the relationship between high pressure metamorphism and ophiolite emplacement in Oman and will be used to develop a tectonic model that will have sufficient temporal control on the large-scale tectonic events. The ultimate goal of this research is to explain why high pressure metamorphism developed in the absence of continent- continent collision or oceanic crust subduction beneath the continental margin.

蓝片岩、C型榴辉岩和其他高压 变质岩石产于基底和陆台 阿曼东北部Saih Hatat顶点的沉积物。 的 蓝片岩和榴辉岩构成一个连贯的原地地形 在结构上被两个推力桩覆盖， 高压变质组合 整个序列 覆盖在塞梅尔蛇绿岩推覆体之上 这些高压变质作用的构造背景 岩石的独特之处在于它们出现在被动大陆中 边缘没有发生陆-陆碰撞， 它们与未变质的特提斯塞梅尔的结构关系 蛇绿岩推覆体 NSF被要求提供两年的支持， 详细的野外岩石学、地球化学和年代学 阿曼东北部高压变质作用研究 本研究 目的是（a）限制压力-温度条件， 变质作用和压力-温度-时间重建 不同构造地形（B）的发展路径 高海拔地区各种岩性的岩石成因网格 压力变质岩;和（c）建立年龄的 变质作用和隆升速率。 这项研究的结果将制约关系 高压变质作用与蛇绿岩侵位之间的关系 阿曼，并将用于开发一个构造模型， 对大规模构造事件具有充分的时间控制作用。 这项研究的最终目的是解释为什么高 压变质作用是在没有大陆- 大陆碰撞或洋壳俯冲 大陆边缘