Mineralogical and geochemical approaches to tectonic problems

这项拟议的工作使用岩石的矿物成分来更好地了解地球构造历史的各个方面。第一部分工作是在新斯科舍省近海的斯科特盆地进行的，那里的石油和天然气都是从深埋的砂岩中开采出来的，这些砂岩有1亿到1.5亿年的历史。我分析砂岩中的矿物，以确定沉积在大型三角洲中的沙子的原始来源。为三角洲提供沙子的河流很可能受到北大西洋和拉布拉多海逐渐开放的影响。河流输运的砂体类型影响着砂岩作为油气储集岩的质量。盆地内流体的运移也影响到储集层的质量。我将使用矿物胶结物及其流体包裹体的证据来了解埋藏盐的运动如何影响流体运移和储集层质量。这项工作的第二部分使用花岗岩等火成岩中的矿物，以更好地了解母岩浆来自哪里，岩石在哪里结晶，以及它们是如何被后来的成矿流体改变的。这项工作的这一部分旨在更好地了解活动俯冲带背后大陆地区的构造历史。本科生和研究生将接受利用矿物解决地质问题的方法方面的教育，这些矿物有助于解决更广泛的构造问题。

The proposed work uses the mineral composition of rocks to better understand aspects of the Earth's tectonic history. The first part of the work is carried out in the Scotian Basin, offshore Nova Scotia, where both oil and gas have been produced from deeply buried sandstones that are 100 to 150 million years old. I analyse minerals from the sandstones, to determine the original source of the sands that were deposited in large deltas. The rivers supplying sand to the deltas were likely controlled by the effects on the landscape of progressive opening of the North Atlantic Ocean and Labrador Sea. The type of sands transported by rivers influences the quality of the sandstones as reservoir rocks for oil and gas. The migration of fluids within the basin also influences reservoir quality. I will use evidence from mineral cements and their fluid inclusions to understand how movement of buried salt affected fluid migration and reservoir quality. A second part of the work uses minerals in igneous rocks such as granites to better understand where the parent magmas were derived from, where the rocks crystallised, and how they were altered by later ore-depositing fluids. This component of the work is directed at understanding better the tectonic history of continental areas behind active subduction zones. Undergraduate and graduate students will be educated in methods of geological problem solving using minerals that contribute to broader questions of tectonics.