Geochemical and Dynamical Evolution of the Calapagos Hotspot

这个项目将继续对加拉帕戈斯群岛的熔岩进行采样和地球化学分析，以确定加拉帕戈斯群岛热点的性质。采样、分析和定年，结合重力数据分析，将允许测试洋中脊玄武岩物质进入加拉帕戈斯群岛羽流中心的热携带。在了解海底岩石的地球化学方面，最有趣的问题之一是确定产生在正常洋脊轴环境中发现的玄武岩的过程和与海底深部热点羽流相关的过程之间相互作用的性质地幔。对加拉帕戈斯台地岩石的初步研究表明，台地内部的岩石看起来像正常的海中脊玄武岩，而台地边缘的岩石成分类似于羽状岩石。这个岩石取样和分析项目将有助于测试地球物理学家提出的一个有趣的假设，即羽流的动力学可以产生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丰富的经验，麦克伯尼博士在加拉帕戈斯群岛做过大量的工作，理查德博士提出了正在测试的假设。Drs。邓肯和怀特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. Richard has developed the hypothesis that is being tested. Drs. Duncan and White provide the necessary analytical expertise.