Jiubagou tremolite jade deposit in Golmud district is one of the typical Kunlun jade deposits. The metallogenic mechanism and age of this deposit are determined based on the systematic study of field geological characteristics, mineral chemistry, ore body occurrence, geochemical characteristics of ore-bearing strata and intrusion, and diagenetic age. The metallogenic intrusive rock is dominated by porphyritic two-mica monzogranite with a zircon U-Pb age of 427.1±4.7 Ma. Actinolite is developed in skarn of magmatic hydrothermal metasomatism, while tremolite is developed in the tremolite jade. They have obviously different mineral chemical characteristics. Combined with the whole rock trace element characteristics of magma, wall rock, the tremolite jade and the skarn, it is proposed that the magma intrudes into the siliceous dolomite and causes the contact thermal metamorphism, which leads to the direct metamorphism between the dolomite and the siliceous mass and forms the tremolite deposit.

A precise Re-Os isochron age of 297.2±4.3 Ma for the molybdenite and a zircon U-Pb age of 301.1±4.0 Ma for the ore-bearing granite porphyry determined that the age of diagenesis and mineralization of Zhunsujihua porphyry Mo-Cu Deposit is from Late Carboniferous to Early Permian. The barren granodiorite in this mining area yielded a zircon U-Pb age of 301.2±2.2 Ma, which is consistent with that of granite porphyry. Amphibole and biotite in granitic rocks and their geochemical characteristics of high Rb, Th, Ba, and low P, Ti suggest that granite porphyry and granodiorite belong to I-type granites. Relatively low Re, Mg#, Nb/Ta, Zr/Hf values, coupled with whole-rock Sr-Nd isotopes (low ISr and positive ε_Nd(t)) signify that they are mainly originated from a juvenile lower crust source derived from depleted mantle. It can be recognized from the whole-rock major and trace element data that significant fractional crystallization occurs during magmatic evolution, which is beneficial to further enrichment of Mo in the melt. Using the Ce⁴⁺/Ce³⁺ ratio in zircons to calculate the oxygen fugacity of magma during fractionation, it is found that the oxygen fugacity of granite porphyry is relatively high (average ΔFMQ is +4.8), and that of the granodiorite is relatively low (average ΔFMQ is +2.2), indicating that magma with high oxygen fugacity is more conducive to mineralization.