五台山地区原金刚库组中含蓝晶石组合的变质作用及其意义

本文对山西五台山地区与超镁铁质岩密切共生的含蓝晶石的各类片岩进行了研究。研究发现，在蓝晶石铝直闪石片岩中存在一种特殊的冠状体结构，即蓝晶石和铝直闪石被它们之间内圈的十字石十刚玉十绿泥石和外圈的堇青石所包绕。这种特殊的反应边结构，说明岩石曾处于较高的压力条件下（０．９～１．４ＧＰａ），然后经历了明显的近等温的减压过程。其它类型的含蓝晶石片岩，也包含了高压变质矿物组合，并经历了同样的变质演化过程。这种演化历史与该区经历了古洋壳俯冲，消减，弧陆碰撞和伴随的迅速折返和抬升是密切有关的。

The Metamorphism and Significance of Kyanite-Bearing Assemblages from the Original Jingangku Formation of Wutaishan area

There are four types of kyanite-bearing schists in the original North Jingangku Formation of the Wutai Group. One of them is called kyanite-gedrite schist which mainly consists of gedrite and kyanite.There is a corona texture in the rocks, some minerals form a rim around the kyanite grain and develope as a result of reaction between the gedrite and enclosed kyanite. There is more than one rim which consists of an inner rim of staurolite, corundum and chlorite with an outer rim of cordierite. The development of corona texture in the kyanite-gedrite schist implies a direct transition from an assemblage typical of high pressure and moderate temperature to an assemblage typical of moderate pressure and temperature. The obvious decompression implies that the rocks have experienced a related subduction-uplift process along converging plate boundaries.