Ag-Cu-Mo Metallogenic Series Of Yanshanian Magmatic Hydrothermal In Diaoquan, Shanxi Province

Abstract:Diaoquan mine was a large skarn Ag-Cu deposit. On the basis of field work, using the theory on metallogenic series, we predict this mining area has deep molybdenum ore, which is verified by the engineering. Using methods and means of fluid inclusion, stable isotopes and geochronology etc., we research on the nature, evolution and origin of the ore-forming fluids, the Source of ore-forming materials, formation age and genesis of ore etc.. Ultimately we establish metallogenic model of the Mo ore. According to the four elements of classifying metallogenic series, we analyze Ag-Cu deposit and Mo deposit of Diaoquan, for understanding the temporal and spatial distribution characteristics and ore genesis of deposits Diaoquan mining area. Finally we made the following main results and understanding:(1)Ag-Cu ore and Mo ore of Diaoquan have the same metallogenic background and they formed in a mesozoic volcanic basin. The ore is strictly controled by Diaoquan complex body and annular contact zone. In general, the silver-copper orebody is hosted above the molybdenum orebody.(2)Diaoquan rock mass, Ag-Cu ore and Mo ore were all formed in Yanshanian. The Single-Zircon U-Pb Age of quartz porphyry, granite porphyry and biotite quartz monzonite are (129.5±2.2)Ma,(154.5±1.1)Ma and (163.7±1.8) Ma, respectively, belonging to Yanshan period. They are the ore-controlling rock mass. These age show the formation of they were sequential. Re-Os molybdenite ages of Mo deposit is (129.5±2.2)Ma. Using the lead isotopic composition of copper-silver ore obtain single-stage model ages are similar to biotite quartz monzonite’s, that indicates their formation ages are close.(3)The source of rock-forming and ore materials are the mixing of crustal materials with mantle components. Geochemistry study of elements and characteristic of Pb, Sr isotope show that the source of quartz porphyry, granite porphyry and biotite quartz monzonite are the mixed Crust-mantle materials.Rhenium content of Re-Os isotope of Mo deposit and characteristic of Pb isotope of Ag-Cu deposit indicate that the source of those two deposits are the mixed Crust-mantle materials.(4)Hydrogen and oxygen isotopes results of Ag-Cu deposit and Mo deposit show that δDV-smow between-72‰and-126‰, and the δ18OH2O is between-2.4‰and8.73‰. It means that the ore-forming fluid of those two deposits are Mixed atmospheric water and magmatic water, mainly.(5)Ag-Cu deposit and Mo deposit of Diaoquan have the same metallogenic background and the mineralization occurred at Yanshan period, the ore-forming fluid and material of those two deposits are similar. Orebody is strictly controled by Diaoquan complex body and annular contact zone. We find out Diaoquan ore is a Ag-Cu-Mo Metallogenic Series of Yanshanian Magmatic Hydrothermal.