Temporal and Geochemical Evolution of the Society Islands Hotspot Lineament

该项目将继续研究时间和 社会群岛链的石化演化。 火山 深成岩和上地幔捕虏体 收集 评价母岩浆和分异机制 碱性海洋岛屿和地球化学变化 这些火山 这些研究将与更好的研究形成对比。 已知的，但也许是非典型的，夏威夷拉斑玄武岩火山。 两 线性构造被认为来自太平洋板块运动， 稳定热点，以及对比鲜明的地球化学演化 应该揭示热点结构的复杂性， 熔体 海洋岩石圈的贡献。 超过150个样品 从塔希提岛的两座火山中收集到的 岩石学描述和他们的年龄确定。 这些 调查现在将扩大到其他火山在 社会群岛，并将涉及一个合作计划， 俄勒冈州的放射性、地球化学和实验研究 康奈尔大学的威廉·白色进行了同位素分析。 一 大量新的样品和地质图正在 由法国火山学家R. Brousse和H.巴克斯

This project is to continue studies of the temporal and petrochemical evolution of the Society Islands chain. Volcanic and plutonic rocks and upper mantle xenoliths have been collected to evaluate the parental magmas and differentiation mechanisms for alkaline oceanic islands and geochemical variations within these volcanoes. These studies will contrast with the better known, but perhaps atypical, tholeiitic Hawaiian volcanoes. Both lineaments are thought to arise from Pacific plate motion over stationary hotspots, and the contrasting geochemical evolutions should reveal complexities in hotspot structure and possible melt contributions from the oceanic lithosphere. Over 150 samples collected from two volcanoes on the island of Tahiti have been described petrographically and their ages determined. These investigations will now be extended to other volcanoes in the Society Islands and will involve a collaborative program of radiometric, geochemical and esperimental studies at Oregon State, and isotopic analyses by William White at Cornell. A large number of new samples and geological maps are being supplied by French volcanologists R. Brousse and H. Barsczus.