CLOSING OF EASTERN QINLING PALAEOOCEAN AND COLLAGING BETWEEN THE NORTH CHINA AND YANGTZE BLOCKS

Eastern Qinling Palaeoocean is one developed in late Proterozoic and closed during Silurian-Devonian(420-400Ma). At the late stage of closing, collage between the north China and Yangtze plates took place, which did not end until Carboniferous (340Ma).The northern part of Qinling Palaeoocean (the southern margin of the north China plate) was turned into an active continental margin with a system of trench-island arc-back arc basin formed from late Ordovician, but its southern part (northern margin of Yangtze plate) remained a passive continental margin. The two kinds of continental margins mentioned above had been collaged from Devonian until Carboniferous. With the basis of the following informations: the tectonic assemblage and its collacative relations of major nappes; the inversion of metamorphic facies and the characteristics of strain markers within the nappe sheet and the measurements on strain parameters (the nappes developed during 420-340Ma); and the studies of foreland basin, the tectonism of the north China and Yangtze blocks is a collisional collage accompanied by obduction and a dextral shearing.