Geology and Recent Volcanology of Nevado del Ruiz Volcano, Colombia

一个综合的三年制课程，包括地质学，地球物理学， 和地球化学计划的目的是研究 位于哥伦比亚的Nevado del Ruiz活火山。 自11月以来， 1985年火山爆发后，PI一直在从事各种各样的 鲁伊斯的初步项目表明， 对火山的看法可能是错误的。 为了提高 我们的理解，并促进一般概念 安第斯火山作用的模型，一个四个任务的计划已经制定： 1)对火山群的详细地质研究包括 火山作用的时代、演化、喷发 动力学、岩石学和火山灾害。 2)最近的一项研究 九个已知的火山点记录了火山的行为 层广泛分布在该地区。 喷发量， 动力学和进化将是一个主要的焦点。 3)详细 重力研究，以评估和模拟地下结构 鲁伊斯 大多数关于不寻常的方面的问题， 鲁伊斯的形式和行为可以解决，如果一个未被承认的 火山口确实存在。 4)继续分析 地热系统及其对岩浆萌发的响应 将努力对该系统进行更全面的取样， 分析改造产物，并确定其年龄， 与地质演化的关系。 其他同位素 将进行研究，以了解深海的性质， 储集层及主要组分和次要组分的来源。 研究的目标是建立一个综合模型， 主要的北方安第斯火山中心，然后可以应用 与其他环太平洋地区开发的技术相比， 火山

An integrated three-year program including geology, geophysics and geochemistry is planned for the purpose of studying the active volcano Nevado del Ruiz, Colombia. Since the November, 1985 eruption, the PI has been engaged in a diverse set of preliminary projects at Ruiz which suggest that previously held beliefs about the volcano may be in error. In order to improve our understanding and to contribute to the general conceptual model of Andean volcanism a four-task program has been developed: 1) A detailed geological study of the volcanic complex including analyusis of the age of volcanism, its evolution, eruption dynamics, petrology, and volcanic hazards. 2) A study of recent behavior of the volcano as recorded in the nine known tephra layers distributed widely over the region. Eruption volumes, dynamics and evolution will be a primary focus. 3) A detailed gravity study to evaluate and model the subsurface structure of Ruiz. Most of the questions about the unusual aspects of the form and behavior of Ruiz could be resolved if an unrecognized caldera were actually present. 4) A continued analysis of the geothgermal system and its response to the mesurgence of magma. An effort will be made to more completely sample the system, analyze the alteration products, and determine their age and relationship to the geological evolution. Additional isotopic studies will be undertaken to understand the nature of the deep reservoir and the origins of the main and minor constituents. The goal of the research is to produce an integrated model of the major northern Andean volcanic center which could then be applied to and compared with those developed at other circumPacific volcanoes.