Geochemical Characteristics and Mineralization of Narigongma Porphyry Cu-Mo Deposit in Qinghai Province

The Narigngma deposit is a typical porphyry Cu-Mo deposit located in the north metallogenic belt of Sanjiang Plain. Based on the features of Narigongma deposit, and through a systematic summary of the deposit geochemistry characteristics as well as mineralization information, following results are obtained: ① The Narigongma deposit formed in the early Himalayan movement. The metallogenic material was mainly composed of granitic porphyry from lower crust. The ore-forming fluids derived from magmatic hydrothermal. The sulfur in the deposit is originated from a mixed sulfur source that consisted of magmatic sulfur (mainly) and the extracted sulfur by ore-forming fluid from the adjacent rock. Deposit formation is related to transformation of regional tectonic and stress of eastern margin of the Tibetan Plateau. ② Based on the results, an ideal metallogenic model of Narigongma Cu-Mo deposit is established, and it is considered that the deposit forming background may be partial extensional environment under thrust nappe squeezed conditions. The tensile antihypertensive and the properties of the surrounding rock caused the current situation of rich-molybdenum and poor-copper. Hydrothermal alteration is developed in the deposit, and sericitization is closely related to ore body, while the potassic alteration range is small, having little relationship with mineralization. The erosion degree of Narigongma mining area is strong, while the erosion degree in southeast of Narigongma deposit is relatively small. So in the peripheral exploration process, we should take into account the skarn-type ore bodies.