蓝片岩及其有关高压变质带研究的新进展

通常认为蓝片岩主要分布在中新生代的造山带中，其成因与大洋板块的俯冲作用有关；而大陆上的蓝片岩一般与蛇绿岩和混杂岩伴生代表了古板块的缝合线。但近来研究发现，蓝片岩的矿物组合、时空分布和原岩建造多种多样。归纳起来可分为两种类型：科迪勒拉型和大陆内部型。不同的蓝片岩是在不同的大地构造环境下由不同的成因机制形成的，还是仅在洋壳俯冲环境中，由于不同的物质卷入俯冲带，引起俯冲过程中动力学机制变化形成的，是当前蓝片岩研究中至为重要的问题。

PROGRESS IN THE STUDY OF BLUESCHISTS AND RELATED HIGH PRESSURE METAMORPHIC BELTS

It has been thought that blueschists mainly occur in Cenozoic-Mesozoic oro-genic belts,and that their formation was related to the subduction of oceanic plate,whilethe blueschist belts within continents,commonly associated with ophiolites and melange,represent the paleo-plate suture.Recent studies,however,have reveaied that blueschistsare not as simple as previously considered.The mlneral assemblages,temporal-spatial dis-tributions and protolith formations of the blueschists characterized by the presence of sodicamphiboles such as glaucophane and crossite are diverse,There are two types ofblueschists,i.e.Cordilleran and intracontinental.Whether the different types ofblueschists are formed in different tectonic settings with different genetic mechanisms,orrelated to the variance of dynamics during subduction due to the involvement of differentmaterials is the key question in the study of blueschists today.