The Kuco-Gamba basin with east-west direction of apical axis is located at the Nyalam and Gamba Counties in Southern Tibet. This area belongs to the northern Himalayas tectonic district. The major sedimentary materials were clastics in Lower Cretaceous and black shale mainly concentrates to the Fourth-Fifth Kuco Formation and Dongshan Formation. The sedimentary materials of black shale were very fine-clastic and they were mainly composed of argillaceous and douke sedimentary. The ratio of sand/mud when the sedimentary process finished was low. There were some rhythmic layering which was composed by fine grained sandstone and siltite in submarine fan. The black shale richly contains lot of siderite and calcareous aerites produced under a reduction special marine condition. There are a few ammonite fossils and so on in it. The sedimentary face changed slowly and the seawater was in a low-energy and strong reduction environment. The rare earth assemblage pattern of douke in black shale extremely approach the basalt standard pattern and this demonstrated that the sedimentary possibly accompanied by the volcanic activity even involved with mantle materials. The thickness of Lower Cretaceous black shale in this
basin is huge and the structure is simple. Its comprehensive geological characteristic demonstrated there are good conditions for hydrocarbon producing. Some positive factors will be worth taken in the future potential appraisal of oil gas resources in northern Himalayas.