The Late Paleozoic-early Mesozoic Tectonic Frame In The Western Kunlun-Karakorum Area

The late Paleozoic-early Mesozoic strata in the Western Kunlun-Karakorum area are main research object and the accreting orogenic theory is used for structural analysis in this paper. The methods of sedimentology, petrotectonics, geochemistry and their interdisciplinary are used to determine the basin type. On the basis of studying on orogenic stratigraphy, especially the fossil of strata,this paper documents the time series of basin filling, relationship between basins and the time coordinate of orogenic process. The research method of orogenic ancient geography was used in erecting the tectonic-paleo-geographic units and their spatial configuration in the orogenic, and hence reflecting the orogenic polarity. The final target is to attempt to define the fine orogenic course. It is the first to research the late Paleozoic-early Mesozoic strata, rock assemblages and distribution in Western Kunlun-Karakorum systematically. The facies palaeoareal maps in different stage have been drawn. By roundly analyzing the basin filling sediments, the fill rules, the trace elements of sedimentary rocks and the geochemical characteristics of volcanic rocks, The Aqiang-kuerliang baisn is considered to be a marginal rift basin formed on the basis of back arc foreland basin during Devonian. The Subashi–Aoyitage basin to be remnant back-arc basin, the Kaleilatashi-Mazha to be the combination of fore-arc basin, island arc and interarc basin. These tectonic units are located to the north of Subashi-Kangxiwa-Waqia juncture, and possess clear arc-basin system. They are tectonic units of active continental margin. The temporal and spatial configuration of these units is very similar to nowadays tectonic frames in the east sea of China——Filipine Sea. The late Paleozoic-early Mesozoic sediments in Tianshuihai-Karakunlun area were based onland block. They were steady mesa sediments from Devonian to early Carboniferous. In late Carboniferous the south was slope-deep basin, the north was continental segment, and formed a passive continental marginal basin dipping to south. Western Kunlun and Tianshuihai–Karakunlun developed independently by middle Permian, and loosely joined together at the end of middle Permian. From late Permian to middle Triassic, there was a residual sea basin between Western Kunlun and Karakunlun, which was the Western extension of Bayankara basin. The basin closed in late Triassic, the whole research area joined together, and turned into intraplate evolution phase.