RUI: Petrologic Evolution and Tectonic Setting in the Sutter Buttes Volcano, California

9706682豪斯巴克这个项目旨在研究鲜为人知的萨特·巴特斯火山，这是一座孤立的火山，包含着整个加州中央山谷唯一的本土岩浆马季奇岩石裸露。这座火山由火山穹顶的中心核心组成，周围环绕着一个巨大的碎裂围裙，记录了该地区火山爆发的漫长演化。苏特巴特斯的火山岩代表了从流纹岩到镁铁质安山岩的各种亚碱性系列，喷发于早更新世，当时北美西部板块边界从俯冲到转换断层的深刻构造转变。萨特巴特斯独特的构造背景为理解这种类型的过渡期间的岩浆生产提供了一个前所未有的机会。建议建立综合地质填图、岩石学记录、显微探针矿物分析和火山岩及其基底的40Ar/39Ar年代学研究框架。在这个阶段，尚不清楚苏特巴特是否与其他岩浆特征有关，如瀑布或索诺马和克利尔湖地区的年轻火山活动。这项工作的结果应该会限制这座独特火山的一些成因特征，并有助于将其岩浆作用纳入区域构造框架。

9706682 Hausback This project aims at studying the poorly known Sutter Buttes, an isolated volcano that contain the only indigenous mag matic rock exposures in the entire Central Valley of California. The volcano is composed of a central core of volcanic domes surrounded by a large fragmental apron that record a lengthy evolution of explosive volcanism in this area. The volcanic rocks of Sutter Buttes represent a diverse sub-alkalic suite ranging from rhyolite to mafic andesite that erupted in early Pleistocene time, during the profound tectonic transition from subduction to transform faulting, of the western North America plate boundary. This unique tectonic setting of the Sutter Buttes provides an unprecedent opportunity to understand magma production during this type of transition. It is proposed to establish a framework of integrated geological mapping, petrographic documentation, microprobe mineral analyses, and 40Ar/39Ar geochronologic studies of the volcanic rocks and their basement. At this stage, it is unclear if the Sutter Buttes are related to any other magmatic feature, such as the Cascades or to the young volcanic activity in the Sonoma and Clear Lakes areas. The results of this work should constrain some of the genetic features of this unique volcano and help put its magmatism into the regional tectonic framework.