MARGINS: Neogene Evolution of the Costa Rican Arc

9975339 Gans中美洲火山弧的哥斯达黎加段是研究弧岩浆活动过程的绝佳天然实验室。 哥斯达黎加的成层火山群是弧火山活动漫长历史的最新“快照”，至少可以追溯到中新世早期。 了解哥斯达黎加俯冲工厂的主要限制之一是，前全新世弧的历史知之甚少。 我们建议进行详细的地质填图和全面的40 Ar/39 Ar年代学调查的中新世更新世火山剖面从整个哥斯达黎加的目标，更好地建立弧火山作用的空间-时间-成分-体积模式。 这样一个数据库将有助于解决的问题和问题包括：在过去的不同时间，活跃的弧在哪里？ 哥斯达黎加火山活动的时间-体积-组成关系是什么？ 哥斯达黎加岛弧的深成根源的性质是什么？侵入岩的体积和成分与同时代的火山岩相比如何？ 该数据库将对大陆火山弧如何演变以及弧环境中各种俯冲参数（收敛速度、板片年龄、沉积物通量）和产出产物（岩浆体积和化学性质）之间的关系提供重要的新的认识。

9975339GansThe Costa Rican segment of the Central American volcanic arc is a superb natural laboratory to investigate processes related to arc magmatism. The chain of active stratovolcanoes in Costa Rica is the latest "snapshot" in a prolonged history of arc volcanism that dates back to at least the early Miocene. One of the main limitations to understanding the subduction factory in Costa Rica is the fact that pre-Holocene arc history is poorly known. We propose to conduct detailed geologic mapping and a comprehensive 40Ar/39Ar geochronological investigation of Miocene to Pleistocene volcanic sections from throughout Costa Rica with the goal of better establishing the space-time-composition-volume patterns of arc volcanism. The sort of questions and problems that such a database will help address include: Where was the active arc at various time in the past? What are the time-volume-composition relationships for Costa Rican volcanism? What is the nature of the plutonic roots to the Costa Rican arc and how do intrusive volumes and compositions compare to coeval volcanic rocks? This data base will shed important new light on how continental volcanic arcs evolve and on the relationships between various subduction parameters (convergence rate, age of slab, sediment flux) and output products (magma volumes and chemistry) in arc environments.