1:250 000 Sinuowushan and Shiquanhe Sheets in Xizang

The stratigraphic developments have been achieved in the geological survey within the extent of the 1:250 000 Sinuowushan and Shiquanhe Sheets in Xizang, including the delineation of the Nyainqentanglha Group Complex on the Zanda landmass, recognition of the Jianzhanong Formation in the Coqen-Xainza terrane and re-establishment of the Tangnale Formation, and subdivision of the Zenong Group volcanic rocks. The Zenong Group arc volcanic rocks indicate an Early Cretaceous age, and Shiquanhe ophiolite zone a Late Jurassic to Early Cretaceous age. The Caili Group is subdivided as well. Lithologically, the volcanic rock series can be observed in the strata of varying ages. The volcanic apparatus are mapped. The Mesozoic and Cenozoic plutonic intrusive rocks are grouped into the Lhagoi Kangri and Gangdise granite zones. The magma-mingled rock series are observed. Tectonically, there exist the northern and southern branches of the Yarlung Zangbo suture zone in these Sheets. The subduction and oceanic-ridge ophiolitic suites may be discriminated in the Shiquanhe zone. The southern branch of the Bangong-Nujiang suture zone is obliquely connected with the Shiquanhe zone in the north.