Field and geochemical studies of continental tectonic processes

在接下来的五年里，我打算进行的研究包括：(1)研究加拿大科迪勒拉和邻近的加拿大西部沉积盆地至少两个断面的热史。这将有助于我们更好地理解造山“事件”与盆地中的沉降/沉积事件之间的联系；这也将有助于限制盆地中石油的生成和运移的时间。(2)继续在加利福尼亚海岸山脉北部进行测绘和磷灰石氦测年，试图利用磷灰石氦化石部分保留带内的等时线作为这一大型、多重变形地形的结构标志。这是一种新的定年方法作为地球化学填图工具的新应用。如果成功，这将大大改善对扭张盆地，特别是沿Maacama断层的运动学演化的理解。(3)建立中部盆地和山脉省部分地壳的热模型；这项工作是基于对内华达州南维尔京山脉地壳暴露中放射性生热元素的分布的研究。它应该允许测试在第三纪伸展期间需要热的、流体的地壳中层的模型，以及关于该区域的元古界非造山花岗岩是由于对其他稳定的地壳进行放射成因加热而形成的原地熔融形成的建议。(4)对加利福尼亚州内华达山脉和内华达州南维尔京山脉的样品中含有大部分放射性元素的矿物进行的研究。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与后来的热液蚀变的控制。

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.