The Dynamics of UHP Tectonism: Does the Western Gneiss Region Consist of Multiple (U)HP Blocks With Different Histories?

超高压构造运动的动力学：西部片麻岩地区是否由多个具有不同历史的（超）高压块体组成？

• 批准号: 0911485
• 负责人: Bradley Hacker
• 金额: --
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0911485&HistoricalAwards=false
• 关键词: Dynamics; UHP; Tectonism; Does; Western

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The margins of continents have been subducted to profound depths (more than 100 km) deep within Earths interior many times throughout the last 500 million years; this process has likely had a major influence on the composition and evolution of the continents and underlying mantle. Understanding how such rocks form and are returned to Earths surface continues to be one of the outstanding questions about plate tectonics. This research uses an enormous region of high-pressure rocks in Norway to understand whether such regions form from one large piece or from many smaller pieces. The impact of this research should be considerable within the earth sciences community because the Norwegian terrane is an archetypal example of continental subduction.The research approach is two-pronged: U-Pb zircon dating of eclogite to assess whether crustal blocks with different ages exist, and structural petrology to characterize shear zones between the blocks. Following careful petrology, eclogite-facies zircon genesis will be assessed by optical and back-scattered electron petrography, cathodoluminescence, trace-element abundances, and Raman spectroscopy. After reconnaissance secondary-ion mass spectrometry and laser-ablation multi-collector inductively coupled-plasma mass spectrometry dating, single zircon grains and grain fragments will be analyzed by high-precision U-Pb thermal-ionization mass spectrometry (TIMS) and chemical-abrasion thermal-ionization mass spectrometry. The strength of this approach lies in its use of state-of-the-art zircon geochronology and petrology, collaboration with researchers at cutting-edge facilities, and our familiarity with other ultrahigh-pressure orogens.

该奖项是根据2009年的《美国复苏和再投资法》（公法111-5）资助的。在过去的5亿年中，多次在地球内部多次将大陆的边际俯冲到深度深度（超过100公里）。这个过程可能会对大陆和潜在地幔的组成和演变产生重大影响。了解这种岩石是如何形成并返回地球表面的如何继续是有关板块构造的重要问题之一。这项研究使用了挪威的巨大高压岩石区域，以了解这些区域是从一个大型碎片还是从许多较小的碎片中形成的。这项研究的影响在地球科学社区中应该是相当大的，因为挪威地层是大陆俯冲的原型例子。研究方法是两种方面的：eclogite的U-PB锆石约会以评估是否存在不同年龄的地壳块，并且是否存在结构性岩石学来表征块之间的剪切Zones之间。经过仔细的质学之后，将通过光学和背面的电子岩石，阴极发光，痕量元素丰度和拉曼光谱法评估Eclogite-Facies锆石起源。侦察次级离子质谱法和激光燃烧器多策略耦合 - 血质质谱测定，单个锆石晶粒和谷物片段将通过高精确的U-PB热离子化质谱法（TIMS）和化学质量质量质量质谱法分析。这种方法的优势在于它使用最先进的锆石地质学和岩石学，与尖端设施的研究人员的合作以及我们对其他超高压牙齿的熟悉。