Collaborative Research: Bear Mountain Intrusive Complex, Klamath Mountains, California: Arc Magmatism and Crustal Anatexis During a Contractional Orogeny

[902807]弧岩浆活动通常被认为与弧环境中的伸展变形有关，但在某些情况下，它也与收缩变形有关。在加利福尼亚的Klamath山脉省，伸展弧岩浆活动与收缩弧岩浆活动交替发生，前者形成钙碱性岩浆，后者形成独特的富k20岩浆。熊山侵入杂岩包含这些岩体类型及其接触光圈。本研究将探讨该区岩体和围岩的运动史和应变史、岩石学和热气压学，以便将岩浆组成与构造环境联系起来。岩石学建模将试图了解包括混染岩在内的岩体和接触带的形成和演化。研究结果将为熊山杂岩和其他弧岩浆活动的辐合和伸展环境提供更清晰的岩浆组成、构造环境和应变组构发育之间的联系。

9902807SnokeArc magmatism is generally thought to be associated with extensional deformation within the arc environment, but in some instances it can be associated with contractional deformation. In the Klamath Mountains province of California, extension related arc magmatism alternated with contraction-related magmatism, but the former resulted in calc-alkaline magmas whereas the latter was associated with distinctive K20-rich magmas. The Bear Mountain intrusive complex contains these pluton types and their contact aureoles. This study will address the kinematic and strain history, the petrography and thermobarometry of the plutons and wall rocks in order to relate magma composition to tectonic environment. Petrologic modeling will attempt to understand the formation and evolution of the pluton and contact zone, including migmatitic rocks. Results will provide clearer understanding of the links between magma composition, tectonic setting and development of strain fabrics, both for the Bear Mountain complex and other examples for arc magmatism in convergent and extensional circumstances.