Measuring the depth extent of processes driving the tectonic evolution of North America

自中生代以来，断裂的大陆边缘碎片、岛弧和大洋高原在北美西缘的增生促进了其生长。然而，前寒武纪年龄的上地幔下这些岩石在加拿大科迪勒拉表明，他们是由旧的岩石圈。因此，看来与北美洲这一部分的增长有关的造山作用仅限于地壳浅层。在地表和更深层次的结构之间的对比年龄代表了一个明显的偏离其他造山系统的地壳和其下地幔具有类似的演化历史的构造风格。这里提出的研究计划旨在了解岩石联合收割机形成大陆的机制，并将通过测量北美西缘的地壳和上地幔来实现这一目标。确定现今地壳和上地幔在缝合带内的结构，并将其结构与稳定的大陆区域进行比较，将澄清大陆生长的过程。的

The accretion of rifted continental margin fragments, island arcs, and oceanic plateaus onto the western margin of North America has contributed to its growth since the Mesozoic. However, Precambrian ages of the upper mantle underlying these terranes in the Canadian Cordillera indicate that they are underlain by older lithosphere. It would therefore appear that the orogenic processes associated with the growth of this portion of North America were limited to the shallow crust. Contrasting ages between terranes at the surface and deeper structures represent a clear departure in tectonic style from other orogenic systems where the crust and its underlying mantle possess a similar evolutionary history. The research program proposed here seeks to understand the mechanisms by which terranes combine to form continents and will accomplish this goal by surveying the crust and upper mantle of the western margin of North America. Determining the present-day structure of the crust and upper mantle within suture zones that juxtapose formerly disparate terranes, and comparing their structures to stable continental regions, will clarify the process of continental growth. The