Abstract:Volcano-sedimentary sequences play an important role in paleogeographical reconstruction of the southern Beishan Region, Central Asian Orogenic Belt. These volcano-sedimentary sequences can be subdivided into 19 lithofacies of four associations based on measured sections in the Shuangyingshan Block (SYSB), southern Beishan Region. Three LA-ICP-MS zircon U-Pb ages were reported from the felsic volcanic intercalations (418.9 ± 1.2 Ma, 417.8 ± 1.2 Ma, and 417.5 ± 1.4 Ma), which indicates an age range of the Lochkovian, Early Devonian for these sections. Coherent and primary volcanic facies distributed on the southern margin of SYSB were interpreted as sediments in lava flows, pyroclastic fall, subaerial pyroclastic flows, and resurgent doming. These facies indicate a subaerial Plinian type volcano. Sequences measured in the Dundunshan Basin, northern SYSB are composed of, in an ascending order, primary volcanic, volcanogenic sedimentary, and fluvial facies, which supports a deepening-upward trend with waning volcanism. These sequences propose that the Dundunshan basin was developed in tectonic extension rather than syn-collision compression.