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.