摘要
The geochemical studies on the main elements of monzogranite, the host rock of molybdenum deposit in Sadaigoumen, reveal that the granite is metaluminous high-K calc-alkaline I-type. The host-rock, monzogranite, has a significant fractionation between LREE and HREE and has LREE enriched patterns with relatively weak Eu negative anomalies (δEu=0.78). La/Sm-La diagram shows that monzogranite is related to fractional crystallization. Trace elements such as Nb, Ta, P, Zr, and Ti are clearly depleted while large ion lithophile elements such as Rb, Th, K, and Ba are enriched. Measured with Biotite aluminum manometer, the average crystallization pressure is 1.83 kbar, namely the emplacement depth is 6.78 km on average. The constraints on the formation of porphyry-type Mo deposits, and the reason why porphyry-type molybdenum was generated, rather than porphyry copper deposit, are discussed. It is finally concluded that this deposit is of the deep source and medium generation porphyry-type molybdenum deposit.