1:250 000 Biru, Dengqen, Lhari and Banbar Sheets in Xizang

There occur the Early Jurassic ammonites in the siliceous rocks from the top units of the Serca massif west of the Dengqen ophiolite zone, bivalves and Betula in the Qoimaco and Biqu Formations south of the Xuela Pass in Dengqen, and Alauda in the slates from the Qoimaco and Mali Formations in Ya'andashan, Baqen. Three lithologic associations may be discriminated in the Duoni Formation, Banbar, that is expected to be defined as a new lithostratigraphic unit where abundant bivalves appear in the limestones. The Lagongtang Formation carbonate rocks on the eastern bank of the Dangmu River in northern Lhaze should be considered as a succession of polycyclic tuff in which abundant plant fossils occur, including Cycas and Filicinae characteristic of the Late Jurassic to the Early Cretaceous vegetation features. The muscovite granite tears are identified in the Duoni Formation north of Ciru, Sog County. The formerly Mengla Formation in the Nyangbo-Conggo zone on the southern flank of the Lhari fault zone is redivided into four successions of strata, in which metamorphic intrusive rocks are hosted. There occur also ophiolites in several places.