Field and geochemical studies of continental tectonic processes

大陆构造过程的现场和地球化学研究

• 批准号: 293248-2007
• 负责人: Brady, Robert
• 金额: $ 1.86万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=456678
• 关键词: Field; geochemical; studies; continental; tectonic

Over the next five years, the research that I intend to undertake includes: (1) A study of the thermal history of at least two transects across the Canadian Cordillera and adjacent Western Canada Sedimentary Basin. This should improve our understanding of ties between orogenic 'events' and subsidence/depositional events in the basin; it should also help constrain the timing of petroleum generation and migration in the basin. (2) Continuation of mapping and Apatite Helium dating in the northern California Coast Ranges, in an attempt to use isochrons within the Apatite Helium fossil partial retention zone as structural markers in this large, multiply deformed terrain. This is a novel application of a new dating method as a geochemical mapping tool. If successful, this should result in significant improvements in the understanding of the kinematic evolution of transtensional basins in general, and along the Maacama Fault in particular. (3) Development of thermal models for parts of the crust in the central Basin and Range Province; this work is based on studies of the distribution of radioactive heat producing elements in the crustal exposures of the South Virgin Mts., Nevada. It should permit testing of models that call for a hot, fluid mid-crustal layer during Tertiary extension, and of suggestions that the Proterozoic anorogenic granites in the region formed by in-situ melting due to radiogenic heating of an otherwise stable crust. (4) A study of which minerals contain most of the radioactive elements in samples from the Sierra Nevada batholith, California and South Virgin Mts., Nevada. This will help determine to what extent the natural distribution of radioactive minerals is controlled by primary magmatic processes versus later hydrothermal alteration.

在未来的五年里，我打算进行的研究包括：（1）横跨加拿大科迪勒拉和邻近的加拿大西部沉积盆地的至少两个断面的热历史研究。这将提高我们对盆地中造山“事件”和沉降/沉积事件之间联系的理解;它还将有助于限制盆地中石油生成和迁移的时间。(2)继续在北方加州海岸山脉进行填图和磷灰石氦定年，试图在这个大的、多变形地形中使用磷灰石氦化石部分保留带内的等时线作为结构标志。这是一种新的测年方法作为地球化学填图工具的新应用。如果成功的话，这将大大提高对一般张扭盆地运动学演化的理解，特别是沿着马卡马断层。(3)建立中央盆岭省部分地壳的热模型;这项工作的基础是对南维尔京山脉地壳暴露中放射性产热元素分布的研究，内华达州。它应该允许测试的模型，呼吁在第三纪伸展热，流体中地壳层，并建议，在该地区的元古代非造山花岗岩形成的原位熔融，由于放射性加热，否则稳定的地壳。(4)一项关于哪种矿物含有来自内华达州岩基、加州和南维尔京山脉样本中的大多数放射性元素的研究，内华达州。这将有助于确定放射性矿物的自然分布在多大程度上受原始岩浆作用和后期热液蚀变作用的控制。