东昆仑造山带东段昆中复合蛇绿混杂岩带及“东昆中断裂带”地质涵义

COMPOSITE OPHIOLITIC MELANGE ZONE IN CENTRAL PART OF EASTERN SECTION OF EASTERN KUNLUN OROGENIC ZONE AND GEOLOGICAL SIGNIFICANCE OF “FAULT BELT IN CENTRAL PART OF EASTERN SECTION OF EASTERN KUNLUN OROGENIC ZONE”

东昆中断裂带中存在多期蛇绿岩组合，分别代表中元古代、新元古代—早古生代和晚古生代３次裂解成洋．断裂带中主要的３类各不相同的韧性剪切构造变形组合分别可与新元古代早期、加里东期末和晚海西期的３次碰撞缝合事件相匹配．“东昆中蛇绿混杂岩带”不能仅限于东昆中断裂带，而应包括原东昆中蛇绿混杂岩带和整个东昆南单元，是一多旋回俯冲碰撞的复合蛇绿构造混杂岩带．东昆中断裂带作为统一的纵贯东昆仑造山带的线性构造变形带应形成于印支期陆内构造变形阶段，是碰撞后的陆内构造变形产物．

Multi_phase ophiolitic rock associations are present in the fault belt in the central part of the eastern section of the Eastern Kunlun orogenic zone. These ophiolitic rock associations represent three times of rifting into oceans that occurred in the Mesoproterozoic, Neoproterozoic-Early Paleozoic, and Later Paleozoic. In the fault belt, are present mainly three different kinds of ductile shearing structural deformation associations that may match the three collisional and sutural events that occurred in the early period of Neoproterozoic, at the end of Caledonian stage, and in the late Hercynian stage. The “ophiolitic melange zone in the central part of the Eastern Kunlun” should not be limited to the fault belt in the central part of the Eastern Kunlun, but should include the original ophiolitic melange zone in the central part of the Eastern Kunlun and the whole unit in the southern part of the Eastern Kunlun. This ophiolitic melange zone can be defined to be a composite ophiolitic structural melange zone with a polycycle of subduction and collision. The fault belt in the central part of the Eastern Kunlun as a unified linear structural deformation belt across the Eastern Kunlun orogenic belt, should have occurred in the Indosinian intracontinental deformation stage, and should have been a product of the intracontinental deformation after the collision.