Dynamics of ductile crust

我们发现矿产资源的能力取决于我们对创造这些矿产资源的过去地质过程的理解，这可以提出地质特征，指导我们找到未来的资源。前寒武纪地盾构成了加拿大的很大一部分，拥有该国的许多矿山以及未被发现的未来资源。尽管我们的矿产资源依赖于地球上一些最古老的岩石，但我们仍然没有完全了解形成它们的大规模地质过程。在我们理解这些早期岩石（和现代岩石）的过程中，有两个主要的谜团。第一个谜是俯冲是如何在板块边缘开始的。俯冲是指一个板块的一个边缘下沉到邻近板块的地壳以下的地幔中，把自己的板块拉到自己身后，穿过地球表面的过程。利用复杂的物理计算机模拟（应力、应变、热流和岩石的热软化），我将研究埋在大陆边缘沉积物下的海底较软的水蚀（蛇纹岩化）岩石的韧性变形是否会破坏那里构造板块的机械完整性，使断裂的边缘下沉，引发俯冲。

Our ability find mineral resources is guided by our understanding of past geologic processes that created those mineral resources, which can suggest the geologic signatures that can guide us to future resources. The precambian shield forms a very large part of Canada, and hosts many of the country's mines as well as undiscovered future resources. Despite this reliance on some of the oldest rocks on Earth for our mineral wealth, we still do not fully understand the large scale geologic processes that formed them. Two major enigmas stand between us and understanding these early rocks (and modern ones). The first enigma is how subduction initiates, at a tectonic plate edge. Subduction is the process by which one edge of a plate sinks into the Earth's mantle below the crust of an adjacent plate, pulling its own plate behind itself across the surface of the planet. Using sophisticated computer simulation of the physics (stresses, strains, heat flows, and heat-generated softening of rocks), I will investigate whether the ductile deformation of the softer water-altered (serpentinized) rocks of the ocean floor, buried under sediments at a continental margin, can destroy the mechanical integrity of a tectonic plate there, permitting the severed edge to sink, initiating subduction.