Petrofabric and Compositional Controls of Physical Properties Across the Granulite - Eclogite Transition

石榴麻粒岩-榴辉岩相的前期研究 在挪威西南部的霍尔斯诺伊岛上， 地震速度和密度在一个陡峭的（1米 厚）过渡。 变化的幅度被假定为 与成分变化（二氧化硅消耗和相对 Fe 2 O3、MgO和CaO的富集）。 变质作用和变形过程中的组构发育。 详细 在暴露的反应前沿，使用paleomag钻头进行取样 将进行测试这一想法。 结果矿物学和 化学成分测定将与地震测定进行比较， 在高围压下的速度测量， 了解控制速度变化的因素。 榴辉岩主要矿物相的详细岩组分析 而麻粒岩将用标准的U阶段方法制造。 地震 速度将从优选取向数据计算， 在实验室中测定的速度进行测试， 围压

Previous investigation of the garnet granulite-eclogite facies transition exposed on Holsnoy Island, southwest Norway, suggests that seismic velocity and density increases across a sharp (1 m thick) transition. The magnitude of the changes are postulated to be related to compositional changes (silica depletion and relative enrichment of Fe2O3, MgO, and CaO) caused by fluid transport during metamorphism plus fabric development during deformation. Detailed sampling, using paleomag drills, across the exposed reaction fronts will be carried out to test this idea. Resultant mineralogical and chemical compositional determinations will be compared to seismic velocity measurements at high confining pressure in order to understand the factors controlling the variations in velocity. Detailed petrofabric analysis of major mineral phases in eclogites and granulites will be made with standard U-stage methods. Seismic velocity will be calculated from the preferred orientation data and tested against velocities determined in the laboratory at high confining pressure.