Geochemical and pressure-temperature evolution of the continental lithosphere

地球内部的历史包括能量和物质在内部和表面之间的转移。这段历史的一些证据是在板块碰撞的大陆边缘形成的变质岩中找到的，例如榴辉岩和蓝片岩。其他证据来源包括火山喷发和大规模花岗岩侵入从深处带出的岩石碎片(捕虏体)。我在加拿大科迪勒拉和其他地方的研究涉及对这些岩石进行野外测绘和取样，并进行实验室研究，包括岩石和矿物的显微镜和化学分析。这些数据与基于实验数据的计算相结合，用来估计岩石形成的压力和温度。对这些岩石形成的压力和温度的估计提供了以下信息：(1)岩石形成的地球深度；(2)将岩石带到地表所需的抬升和剥蚀量；以及(3)变质时地球温度随深度的变化。从内部转移的一些物质包括热的富含水的流体和火成岩熔体。估计这些流体和熔体的组成是这项研究的一部分。热力学计算和稳定同位素研究可以用来估计这些流体和熔体的组成。这项研究的另一个重要部分是变质和火成岩事件的时间，这是通过使用放射性同位素对矿物进行测年来实现的。所有这些研究都可以综合起来，对大量地壳和上地幔的地质史作出全面的解释。

The history of the Earth's interior involves transfer of energy and matter between the interior and the surface. Some of the evidence for this history is found in metamorphic rocks that formed at the margins of the continents where the plates collide, e.g, eclogites and blueschists. Other sources of evidence include pieces of rock (xenoliths) brought up from depth by volcanic eruptions and large scale granitic intrusions. My studies in the Canadian Cordillera and elsewhere involve field mapping and sampling of these rocks with laboratory studies including microscopy and chemical analyses of the rocks and minerals. The data are used in combination with calculations based upon experimental data to estimate the pressure and temperature at which the rocks formed. The estimation of the pressure and temperature at which these rocks form provides information on: (1) the depth in the Earth at which the rocks formed; (2) the amount of uplift and erosion required to get the rocks to the surface; and (3) the variation of temperature with depth in the Earth at the time of metamorphism. Some of the matter transferred from the interior includes hot, water-rich fluids and igneous melts. Estimation of the composition of these fluids and melts is part of the study. Thermodynamic calculations and stable isotope studies can be used to estimate the composition of these fluids and melts. Another important part of this study is the timing of the metamorphic and igneous events and this is accomplished by dating the minerals using radioactive isotopes. All of these studies can be integrated and produce a comprehensive interpretation of the geologic history of large volumes of the Earth's crust and upper mantle.