扬子克拉通西缘穹状变形变质体的类型与成因

TYPE AND ORIGIN OF THE CORE COMPLEXES AND THE DOMAL DEFORMATIONAL-METAMORPHIC BODIES IN THE WESTERN MARGIN OF YANGTZE CRATON

扬子克拉通西缘呈分散状产出的一系列穹状变形交质体，按其结构特征与成因，可将其划分为变质核杂岩，岩浆核杂岩，片麻岩穹隆和构造穹隆四种类型。造山后期—期后，深部上隆，浅部伸展，局部岩浆活动和造山期深熔花岗岩底辟侵位所引起的地壳局部隆升与伸展，是形成该区变质核杂岩和岩浆核杂岩的主要原因；片麻岩穹隆和构造穹隆，则分别为双向挤压收缩体制下，局部熔融—重熔花岗岩同构造被动侵位，和单纯的构造变形与叠加变形形成。它们具不同的时、空分布和控矿特征，是扬子克拉通西缘造山过程中不同构造坏境，不同演化阶段和不同构造体制下的产物。

According to the structure and origin, the domal deformational - mctamorphic bodies scattered in the western margin of Yangtze craton may be divided into four types:metamorphic core complex,magmatic core complex, gneiss dome and strucrual dome.Uplift in depth and extension near sruface, local magmatic activity and diapiric intrusion of syntectonic anatectic granite associated with local crustal uplift and extension were responsible for the magmatic and metamorphic core comlexes. The gnciss domes are attibutcd to partial melting and passive emplacement of bidirectional compressive setting.The structrual domes resulted from tectonic deformation and superposed deformation.They are different in space-time distribution and ore control. They were formed in different evolutionary stages and under conditions of different tectonic regime and setting during the orogenesis in the western margin of Yangtze craton.