江尕勒萨依榴辉岩的主要特征及其地质意义

Main characteristics of the Janggalsay River eclogite andits geological significance

于新疆且末县江尕勒萨依发现两种不同类型的榴辉岩,它们的地质产状、矿物组成、岩石化学成分、地球化学特征及峰期变质温压条件均有明显的差别。北带榴辉岩属暗色富铁型,南带榴辉岩为浅色富镁铝型,两者都具有高压变质带的特征,是塔里木地块东南缘持续俯冲先后与两个或多个前寒武纪微地块碰撞的产物。阿尔金岩群实际上是碰撞拼贴的杂岩带,是加里东碰撞造山带山根之一部分。

Two types of eclogites have been discovered on the Janggalsay River area,Qiemu County of Xinjiang and their geological occurrence,mineral assemblages,petrochemical compositions,geochemical characteristics and peak metamorphic temperature-pressure condition are quite different.The eclogites in north belt of the river are dark and rich in iron,and in south belt are tint and rich in magnesium and aluminium.The two types of eclogites are product of high-pressure metamorphism and were formed by persistent subduction and collision of two or more Precambrian microblocks in the southeastern margin of the Tarim Block. The Aerkin Group is actually a kind of collision complex as a part of the root of the Caledonian collision orogenic zone.