Interaction Between Asthenospheric and Lithospheric Melts: Alkalic Volcanism in the Rungwe Province, African Western Rift

9406109福尔曼这是一项长期研究计划的一部分，该计划综合了关于年轻熔岩的野外、地质年代学、地球化学、同位素、岩石学和实验数据，以确定大陆裂谷火山活动的动力学。之所以选择坦桑尼亚的朗格韦火山省进行详细研究，是因为该地区的样品将有助于理解大规模的地球动力学问题和区域构造问题。一个基本目标是研究软流圈和岩石圈来源熔体混合的地球化学后果。第二个目标是记录各个火山中心熔岩地球化学的时间变化。这项研究中分析的所有样本目前都在手中；只有新鲜的年轻熔岩样本将被使用。高质量的岩石学、矿物学和地球化学(包括不相容的痕量和稀土元素)数据将与同一样品的现有同位素(锶、钕、铅、氧、氦)数据一起解释。Rungwe的调查将使地方和区域综合大陆裂谷火山成因中软流圈-岩石圈相互作用的动力学数据成为可能。

9406109 Furman This is part of long-term research program that integrates field, geochronologic, geochemical, isotopic, petrographic and experimental data on young lavas to determine the dynamics of continental rift volcanism. The Rungwe volcanic province in Tanzania was selected for detailed study because samples for m this area will contribute to understanding both large-scale geodynamic problems and regional tectonic questions. A fundamental objective is to investigate the geochemical consequences of mixing between asthenospheric and lithospheric source melts. A second objective is to document temporal variations in lava geochemistry at individual volcanic centers. All samples analyzed in this study are currently in hand; only fresh samples of young lavas will be used. High quality petrographic, mineralogic and geochemical (including incompatible trace and rare earth element) data will be interpreted in conjunction with available isotopic (Sr, Nd, Pb, O, He) data on the same samples. The investigation at Rungwe will enable both local and regional syntheses of data on the dynamics of asthenosphere-lithosphere interaction in the genesis of continental rift volcanism.