昆仑造山带晚泥盆世沉积特征及构造古地理环境

昆仑造山带基本构造-地层格架奠基于古生代,晚泥盆世是加里东造山旋回和华力西造山旋回转换的关键阶段,加里东碰撞造山和其后的伸展裂陷等记录均存在于晚泥盆世沉积地层中。西昆仑晚泥盆世奇自拉夫组为一套紫红色碎屑岩沉积,属典型的碰撞造山型磨拉石建造,为加里东碰撞造山的产物;东昆仑晚泥盆世黑山沟组和哈尔扎组岩性组合特征与牦牛山组极为相似,均为一套陆相、滨浅海相的碎屑岩、碳酸盐岩和中酸性火山岩组合,为典型的裂陷伸展型磨拉石建造,是晚古生代裂陷伸展盆地演化开始的标志。

THE DEPOSITION CHARACTERISTICS AND TECTONO-PALEOGEOGRAPHIC ENVIRONMENT OF KUNLUN OROGENIC BELT IN LATE DEVONIAN

It was in Paleozoic that the tectonic and deposition system of Kunlun orogenic belt had been formed. Also, it was in the pivotal period that Caledonina orogeny was transformed into Varis orogeny in late Devonian, Caledonian orogeny and its late stretch-rift event had been recorded in late Devonian deposition. Qizilafu Group of late Devonian in the west Kunlun Mountain is characterized by purplish fragmentary rock sedimentation, and is a kind of molasse formation in collisional orogen and the productive substance of Caledonina orogeny. The petrogenetic characteristics of Heishangou Group and Haerzha Group of late Devonian in east Kunlun Mountain are similar to those of Yak Group, as they consist of clastic rocks of terrigenous facies and littoral shallow sea facies, in addition to carbonatite, intermediate-acidic volcanic assemblage, and belong to typical molasse formation in a stretch-rift system, which is indicative of the beginning of basin evolvement in the late Paleozoic stretch-rift system.