Paleozoic active margin slices in the southern Turfan-Hami basin:geological records of subduction of the Paleo-Asian Ocean plate in central Asian regions
东天山吐哈盆地南缘古生代活动陆缘残片：中亚地区古亚洲洋板块俯冲的地质记录

Based on analysis of available geological and geochemical data,this paper states temporal and spatial distributions,rock assemblages and petrological features of slices of the Paleozoic active margins in the southern Turfan-Hami basin,and then briefly discusses tectonic evolution of the Paleo-Asian ocean.The slices consist mainly of Ordovician-Siliurian(?),Devonian and Carboniferous volcano-sedimentary sequences,and Devonian and Carboniferous plutons.The temporal and spatial distribution of those magamtic rocks with various ages implies that the evolution of the magmatic front in the area is characteristic of southwards gradually migration.Those various magamtic rocks are similar both in rock assemblages and geochemistry to the calc-alkaline series ones of the island-arc type.Their above features,in combination with their regional geology,make us get primary conclusions that occurrence of the slices is related to subduction of the oceanic lithosphere plate,which is represented by oceanic remains within the Kangguertg Carboniferous collisional belt,northward under the Siberian paleoplate,and that these slices probably constituted the active continental margin of the Siberian paleoplate in the Paleo-Asian ocean with similar slices in the Ahay mountains,southmost Mongolian and central Great Khing'an ranges.The occurrence of the margin implies that subduction of the Paleo-Asian oceanic plate under the Siberian paleoplate continuously developed from the Ordovician through Carboniferous.