U.S.-Argentina Cooperative Research: Field-Petrologic- Geochemical Study of Recent Volcanic Rocks Erupted Behind the Andean Volcanic Arc

该奖项将支持弗雷德里克 马萨诸塞州理工学院的弗雷和D. 阿根廷国家地质服务局的Delpino。 的 该项目旨在对最近爆发的熔岩进行取样， 活跃的安第斯火山锋面从南纬35度到37度 为了了解阿根廷南部的火山活动 安第斯山脉和智利的火山岩喷发， Argentina. 实地考察和取样位于具有以下条件的地区： 德尔皮诺和同事绘制了地图，但最近 火山特征还没有被详细取样 地球化学研究 有两个主要原因 研究这些火山喷发500-200公里以东的活动 安第斯火山前缘：（1）富含MgO的 碱性玄武岩在阿根廷东部爆发， 直接反映了它们的地幔源区成分， 相对进化的熔岩形成了 （2）通过研究在不同距离喷发的熔岩 研究人员可以确定， 地球化学趋势作为距离智利的函数 沟槽 有了这些信息，他们希望开发新的 对创建过程中所涉及的资源和过程的限制 安第斯火山弧的这一部分 美国方面 地球化学分析和解释专业知识， 了解火山岩的起源和演化。 阿根廷人在野外火山学和 当地的地质和物流。

This award will support field collaboration between Frederick Frey of the Massachusetts Institute of Technology and D. Delpino of the Servicio Geologico Nacional in Argentina. The project aims to sample recent lavas erupted east of the active Andean volcanic front from 35 degrees to 37 degrees S in Argentina, in order to understand volcanism in the southern Andes and the pertinent volcanic rocks erupted in Chile and Argentina. The fieldwork and sampling are located in regions that have been mapped by Delpino and colleagues, but the recent volcanic features have not been sampled for detailed geochemical studies. There are two principal reasons for studying these lavas erupted 500-200 km east of the active Andean volcanic front: (1) it is likely that the MgO-rich alkaline basalts erupted in Argentina east of the front more directly reflect their mantle source composition than the relatively evolved lavas which form the stratovolcanoes on the front; (2) by studying lavas erupted at varying distances across the strike of the front, researchers can define geochemical trends as a function of distance from the Chile trench. With this information, they expect to develop new constraints on the sources and processes involved in creating this portion of the Andean volcanic arc. The U.S. side has geochemical analytical and interpretive expertise in understanding the origin and evolution of volcanic rocks. The Argentines have expertise in field volcanology and in local geology and logistics.