Jurassic and Cretaceous Magmatism, Klamath Mountains CA and OR

这项拟议的研究将调查克拉玛斯山省火成岩的起源，这些火成岩是两个广泛的弧系的残留物。尽管西部的Hayfork/Ironside山杂岩和Rogue/Chetco杂岩是该省规模最大的吸积弧，但它们几乎没有得到详细的岩石学研究。将利用详细的测绘和采样、锆石U-Pb年代学、矿物分析、块状岩石元素分析以及块状样品和矿物分离的同位素分析来研究它们的成因。这些数据将被用来估计源岩的成分，模拟分离结晶和地壳污染的影响，并提供一种手段，将与弧形相关的岩石与邻近的、研究得很好的残弧和弧后岩浆系统进行比较。这些结果将在当地和区域构造活动和变质作用的背景下进行解释，并将用于比较克拉玛斯山省和北美科迪勒拉其他地区的中生代弧岩浆活动。

The proposed research will investigate the origin of igneous rocks in the Klamath Mountain province that are the remnants of two extensive arc systems. Although the systems, the western Hayfork/Ironside Mountain complex and the Rogue/Chetco complex, represent the most voluminous accretionary arcs in the province, they have received little detailed petrologic study. Their origin will be investigated with the use of detailed mapping and sampling, U-Pb (zircon) geochronology, mineral analysis, bulk-rock elemental analysis, and isotopic analysis of bulk samples and mineral separates. These data will be used to estimate the composition of the source rocks, to model the effects of fractional crystallization and crustal contamination, and to provide a means of comparing the arc-related rocks with adjacent, well-studied, remnant arc and back-arc magmatic systems. The results will be interpreted in the context of local and regional tectonic activity and metamorphism, and will be used to compare Mesozoic arc magmatism in the Klamath Mountain province with that elsewhere in the North American Cordillera.