1:250 000 Chagdo Kangri and Burogco Sheets in Xizang

There occur abundant bivalves, brachiopods, corals, ammonites and sponges fossils in the Jurassic strata and Upper Triassic Xiaocaka Formation; pelecypods, brachiopods, ostracods and radiolaria fossils in the Zhanjin and Qudi Formations; pelecypods and plant fossils in the Neogene Suonahu Formation, and fusulinids fossils in the Qudi Formation in the Tubeihu region, which is tentatively identified as Misellina belonging to the warm-water faunas and common in southern China. All these evidences show that the above-mentioned surveyed areas developed into the Palaeo-Tethys during the Early Permian. The radiolaria fossils are found for the first time in the formerly Rola Kangri Group Complex. The 14 C age determinations of the Pleistocene soils from the first-grade terraces along the Bailongbing River and Erchagou zones are dated 15 600±540 Ma and 13 390±670 Ma, respectively, implying that the uplifting of the Qiangtang Plateau once took place during the Pleistocene. The Jurassic organic reefs (patch reefs) are observed as well in places. The lithologic compositions, deformation and metamorphism are ascertained for the Rola Kangri Group Complex, and the Wandaohu ophiolitic tectonic mélange zone is delineated. The Cenozoic granite porphyries cropped out in the central zones of the Sheets are assigned to the shoshonite series and syncollisional granites representing the orogenic products created during the late Yanshanian. The presence of the ophiolite relicts in the Dahengshan tectonic zone indicates that the Jinshajiang suture zone extends westwards to the Dahengshan tectonic zone, and thus may provide important data for the approaches to the tectonic attributes of the Dahengshan tectonic zone. The examination of glaucophane-schist as a kind of high-pressure metamorphic rocks and its association with lawsonite shows that the Hongjishan glaucophane-schist may result from the collision. Other work also includes the investigation of rock types, deformation and metamorphism of the medium-grade metamorphic series from the Gomori Formation Complex (?) and Hongjishan tectonic zone, and of structural features of the faults in the surveyed areas. The Tianshuihe-Wandaohu fault is a facies-controlled sinistral strike-slip fault.