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

SnokeArc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，它可能与收缩变形有关。在加利福尼亚州克拉马斯山脉，伸展相关的弧岩浆活动与收缩相关的岩浆活动交替进行，但前者产生了钙碱性岩浆，而后者与独特的富K20的岩浆有关。熊山侵入杂岩包含了这些岩体类型及其接触光环。这项研究将研究深成岩和围岩的运动学和应变史、岩石学和温压测量，以便将岩浆成分与构造环境联系起来。岩石学模拟将试图了解岩体和接触带的形成和演化，包括混合岩。这些结果将使人们更清楚地了解岩浆成分、构造环境和应变组构发育之间的联系，无论是对于熊山杂岩还是在会聚和伸展环境中的弧形岩浆作用的其他例子来说都是如此。

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.