Geological Features And Tectonic Significance Of Melange Zone In West Kunlun Taxkorgan

Orogenic belt of West Kunlun locates in the northwest edge of the Qinghai-Tibet Plateau,north adjacent to the Tarim Basin,west extending to the Pamir Plateau and south adjacent to Karakoram.The belt is the greatest importance areas in study the Alps-Tethys Himalayan tectonic structure and the ancient Tethys domain.Taxkorgan area is an important turning point in western Kunlun orogenic belt, where the tectonic boundaries(zone) control the West Kunlun tectonic units.Mazar of them - Kangxiwar fault zone which is determined plate tectonic suture and in which ancient Tethys final closed by many experts.The fault zone is studied very well in the region Kangxiwar,but the location of the distribution,structure and characteristics of the property is not clear.The found and study of Taxkorgan tectonic melange not only defined the mazar-Kangxiwar extension of the regional location of the fault zone,but also provided a new and important information of the fault zone with "combination plate" nature.Taxkorgan mélange zone exposes 30-80km width extending from North West to North West.The eastern border is Waqia tectonic fault zone and western is Tae Xi fault.Composition of Melange is complex complicated by different times and different kinds of tectonic plates or block with different era invasived magmatic rocks. Taxkorgan melange could be divided into Paleoproterozoic basement rock-chip,the mainland Sinian plate rift basalt rock,Ordovician-Silurian flysch rock and Carboniferous-Permian volcanic arc Rock-chip by 1:250000 geologic map.High-pressure metamorphic rocks accompanied with the Paleoproterozoic basement rocks composited by the basic high-pressure granulite muddy high-pressure granulite.Muddy high-pressure granulite outputs in the same region with the basic high-pressure granulite,a large area in the output of garnet two-mica schist,including the K-kyanite garnet two-mica schist..Basic high-pressure granulite SHRIMP zircon U-Pb age is 456±30Ma which represents the peak of high pressure granulite facies metamorphic age.Remnants of oceanic basin has been identified early Silurian.Based on the above two matched important proves,we could concluded than Taxkorgan tectonic melange belt generated at the beginning of the Early Paleozoic.Late Paleozoic volcanic rock in the tectonic melange belt show that the reduction and the process of subduction were longer,more complicated.The melange belt of Kangxiwar for the establishment of the nature of the fault zone and in the West Kunlun tectonic evolution of the research is of great significance, which indicates that further discoveries in the West Kunlun region in early Paleozoic there have been plate subduction and collision course,and hinted that the mazar-Kangxiwar fault may represent the original Tethys - the ancient Tethys subduction and final closure of the line.