The Life History of an Arc Volcano: Insights from a Collaborative, Petrologic, Paleomagnetic and Geochronologic Study

智利安第斯山脉第四纪南部火山带 美国科学家小组对这一问题进行了调查， 量化弧母岩浆中的幔源成分， 这些岩浆与弧壳相互作用的程度。 地壳年龄、厚度和年龄的纵向变化 俯冲板块使其成为区域研究的理想目标。 该项目的主要重点是一个非常详细， Tatara-San Pedro（TSP）（36 ° S）的全面调查， 最年轻的建筑师（CA. San Pedro-Pellado（150 ka至全新世） 火山杂岩 这项研究将基于丰富的 关于沿走向和跨走向的区域信息 第四纪活动的变化。 除了其成分的变化，TSP是异常的 从其底部暴露良好：1 km垂直（或复合）剖面 (up到150流量）暴露在深冰川峡谷中， 圆锥体的四分之一。 将对这些切片进行100%采样 逐流基础（化学和古地磁学）结合 通过对大量地壳捕虏体的取样， 选择更新世熔岩，并详细取样两个地表 非均匀的全新世流动。 详细 TSP喷发历史的重建将由 通过整合这些部门， 古地磁变化数据，物理地层学， 地球化学和岩石学以及高分辨率地质年代学。

The Quaternary Southern Volcanic Zone (SVZ) of the Chilean Andes has been investigated by teams of US scientists concerned with quantifying the mantle source components in arc parent magmas, and the degree to which these magmas have interacted with arc crust. Longitudinal variations in crustal age, thickness, and the age of the subducted plate make this an ideal target for regional studies. The primary focus of this project is an exceptionally detailed and comprehensive investigation of Tatara-San Pedro (TSP) (36o S), the youngest edifice (ca. 150ka to Holocene) of the San Pedro-Pellado volcanic complex. This study will be grounded on a wealth of regional information concerning along-strike and across strike variations in Quaternary activity. In addition to its compositional variability, TSP is exceptionally well exposed from its base: 1 km vertical (or composite) sections (up to 150 flows) are exposed in deep glacial canyons from all quadrants of the cone. These sections will be sampled on a 100% flow-by-flow basis (chemistry and paleomagnetism) in conjunction with sampling of abundant crustal xenoliths, lateral sampling of select Pleistocene lavas, and detailed surface sampling of two spectacularly heterogeneous Holocene flows. A detailed reconstruction of the eruptive history of TSP will be made by correlating among these sections through integration of paleosecular magnetic variation data, physical stratigraphy, geochemistry and petrography, and high-resolution geochronology.