Metamorphic History and Fluid-Rock Interactions of Layer 3 of the Southwest Indian Ridge

该项目的目标是全面研究在大洋钻探计划第118阶段期间在西南印度洋海脊的Atlantis II断裂带钻探的变质辉长岩。钻芯代表了近500米的辉长岩，回收率为87%。工作将包括对次生矿物和矿脉组合的详细岩相学和电子显微探针研究，稳定同位素研究和流体包裹体研究。其目的是了解岩石的变质历史，并确定引起不同阶段蚀变的各种变质流体的质量通量。这个项目是首次尝试描述通过钻探获得的大洋地壳第三层岩石的变质和构造历史。这是一套独一无二的样本套装。这一项目应该会对大洋地壳更深部分的性质和演化产生新的理解。该项目是对其他研究人员在同一岩心上进行的原生矿物组合和块体化学研究工作的补充。

The objective of this project is to comprehensively study the metagabbroic rocks drilled from the Atlantis II fracture zone on Southwest Indian Ridge during Leg 118 of the Ocean Drilling Program. The drill core represents of nearly 500 meters of gabbro with 87% recovery. Work will include detailed petrography and electron microprobe studies of secondary minerals and vein assemblages, stable isotope studies and fluid inclusion studies. The goal is to understand the metamorphic history of the rocks and to determine the mass fluxes of various types of metamorphic fluids that have given rise to different phases of alteration. %%% This project represents the first attempt to characterize the metamorphic and tectonic history of rocks from layer three of the oceanic crust that have been obtained by drilling. This is a unique sample suite. This project should produce a new understanding of the nature and evolution of the deeper parts of the oceanic crust. This project complements work to be done on primary mineral assemblages and bulk chemistry on the same core by other investigators.