Evolution of the Galapagos Hotspot - Spreading Ridge System

这是一个项目，目的是继续对平台近海区域的加拉帕戈斯熔岩进行采样和地球化学分析，以确定加拉帕戈斯热点的性质。取样、分析和年代测定，结合重力数据的分析，将能够测试大洋中脊玄武岩物质进入加拉帕戈斯羽流中心的热携带作用。在理解海底岩石的地球化学方面，最有趣的问题之一是确定在正常洋脊轴线上发现的玄武岩形成过程之间相互作用的性质与地幔深部热点热柱有关的环境和过程。对加拉帕戈斯地台岩石的初步研究表明，地台内部的岩石看起来像正常的大洋中脊玄武岩，而地台边缘的岩石成分类似于羽状岩石。这个岩石采样和分析程序将有助于检验地球物理学家提出的关于羽流动力学的有趣假说，该假说可能会导致不寻常的地球化学特征。这个项目的人员是最合适的，因为克里斯蒂博士在海上有相当多的经验，麦克伯尼博士在加拉帕戈斯群岛上做了大量的工作，理查兹博士提出了正在测试的假设。邓肯博士和怀特博士提供了必要的分析专业知识。

This is a project to continue the sampling and geochemical analysis of Galapagos lavas to the off-shore regions of the platform in order to define the nature of the Galapagos hotspot. Sampling, analysis and dating, combined with the analysis of gravity data, will permit the testing of the thermal entrainment of Mid-ocean Ridge basalt material into the center of the Galapagos plume. %%% One of the most interesting problems in understanding the geochemistry of rocks emplaced on the sea floor is the determine the nature of the interaction between processes that generate basaltic rocks that are found in a normal ocean ridge axis environment and process associated with deep seated hot spot plumes in the mantle. Preliminary study of rocks from the Galapagos platform show that rocks from the interior of the platform look like normal mid ocean ridge basalts, whereas those on the margins of the platform have compositions resembling plumes-type rocks. This rock sampling and analytical program will help test an interesting hypothesis developed by geophysicists regarding the dynamics of plumes that can give rise to the unusual geochemical signature. The personnel for this project are most appropriate because Dr. Christie has considerable experience at sea, Dr. McBirney has done considerable work on the Galapagos Islands, Dr. Richards has developed the hypothesis that is being tested. Drs. Duncan and White provide the necessary analytical expertise.