Sedimentary facies and palaeogeography of northern Qilian area during the Middle Cambrian

The sedimentary facies and palaeogeographic analysis in the present paper is based on the field and laboratory examination guided by the thoughts of "tectonic-controlled basin and basin-controlled facies" in integration with lithology, textures and structures, and fossil assemblages. Three sedimentary facies are discriminated including neritic shelf, bathyal and abyssal-oceanic basin facies, followed by the reconstruction of the sedimentary facies and palaeogeographic map of northern Qilian area during the Middle Cambrian. The results of research in this study may provide a helpful approach to the sedimentary facies and palaeogeographic analysis for the orogenic zones.