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

自中生代以来，裂谷大陆边缘碎片、岛弧和海洋高原在北美西部边缘的增生促进了它的发展。然而，加拿大科迪勒拉地区这些地体下面的上地幔的前寒武纪时代表明，它们下面是更古老的岩石圈。因此，与北美这部分地区的生长有关的造山作用似乎仅限于浅层地壳。地表地体和深层构造年龄的对比表明，在构造风格上与其他造山带系统明显不同，在造山带系统中，地壳及其下伏的地幔具有相似的演化历史。这里提出的研究计划旨在了解地体结合形成大陆的机制，并将通过测量北美西部边缘的地壳和上地幔来实现这一目标。确定缝合带内地壳和上地幔的现今结构，并将它们的结构与稳定的大陆区域进行比较，将澄清大陆生长的过程。这个

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