NEW RECOGNITION OF THE NACHITAI GROUP

There occurs a suite of low-grade metasandstone, slate, phyllite, crystalline carbonate rocks, intermediate-basic volcanic rocks and intermediate-acid metavolcanic rocks to the south of Gohmud City in Qinghai province, in the Eastern Kunlun Mountains area. This suite is the"Nachitai Group". The authors took part in l:200000-scale regional geological surveys of the Golmud Sheet（J-46-XXXV） and the Nachitai Sheet（I-46-V） in 1977— 1980, and for the first time discovered several unconformities in this group and collecteed fossils from different horizons. On that basis, the authors have disintegrated the"Nachitai Group"and made a new division, and thus established the Proterozoic Wanbaogou Group, the Upper Ordovician, Carboniferous, Permian and Triassic of the Paleozoic and the Jurassic and Cretaceous of the Mesozoic. Some strata were for the first time discovered on the northern slope of the Eastern Kunlun Mountains, in Qinghai, which provides the grounds for remoulding the history of geological development.