Metallogenic Model And Prediction Of Qiushuwan Copper-molybdenum Deposit, East Qinling

:Qiushuwan copper-molybdenum deposit is characterized by the medium scale in the east Qinling orogenic belt, locating in south margin of North China block and east Qinling belt of Qinling-Dabie collision zone, the north side of the intersection of Shang-Dan fracture and Zhu-Xia fracture. In this study, based on full collection of previous results about the East Qinling, by using the multi-disciplinary theory and method, such as the field geology, regional geology, ore deposit geology, structural geology, petrography, major and trace elements, fluid inclusion, stable isotope, coupled with the high-precision remote sensing interpretation and multi-method geophysical interpretation, for the purpose of prospecting breakthrough, throughout the first study of mineralization, ore-controlling geological; then geophysical, geochemical and remote sensing for technical support; Finally, drilling to verify the main line, depicting the copper and molybdenum mine in Qiushuwan four diagenetic-metallogenic model to determine the prospecting and exploration models, and ultimately achieved major prospecting breakthrough.Two different types of granite of this area of research, the Qiushuwan granite and Qiushuwan porphyry mineralization host rock-oriented, Na2O/K2O<1, the high content of Ba and Sr, with high LREE, but low content of Y, HREE, Yb, Nb and Ti, the high ratios of Sr/Y and La/Yb and low Rb/Sr, the lack of significant Eu anomaly and other geochemical characteristics as well as in in granite QAP classification diagram, granitoids in the Rb-Yb Ta diagram projection, the case of high Ba-Sr granitoids, geese to the Granite Ridge REE patterns showing the flat appeared the Eu Valley or Eu peak REE patterns, map of Ba, Sr. obvious exception, La lower The geochemical characteristics and the projection position of the Sr-Ba-Rb diagram that is low of Ba-Sr granite. The high Ba-Sr granitoids, Qiushuwan output description of the area have occurred in the crust and mantle mixing in140Ma±, on behalf of the collision orogenesis of the district licensing local extensional tectonic stress environment. Jinduicheng, the output characteristics of the South Mud Lake, three Zhuang, Kaminarimon ditch Autumn Tree Bay mineralization porphyry, geochemical characteristics, tectonic setting, source of diagenetic material; their stable isotope characteristics Comparative studies show that the source of these mineral deposits, indicating140Ma±Middle East Qinling outbreak of large-scale tree Bay mineralization period.Interspersed relationship based on mineral assemblages, ore fabric, wall rock alteration and vein can be divided into early (Ⅰ),(Ⅱ) and late (Ⅲ) three mineralization of the period, subdivided into dry silicon Skarn-K-feldspar-quartz stage(Ⅰ1); blasting breccia phase (Ⅰ2); wet skarn stage (I); magnetite stage (Ⅰ4); porphyry copper (molybdenum) ore stage (Ⅱb,) and quartz-sulfide mineralization (Ⅱ s); calcite, barite, quartz stage (Ⅲ). Fluid inclusions can be divided into multi-phase inclusions of S-type containing daughter minerals, L-pure liquid inclusions, C-type CO2-bearing three-phase inclusions, W-type gas-liquid two-phase inclusions, G pure gas inclusions five types. Ore-forming fluids according to the chronological order of temperature, salinity, redox environment, with the regularity of evolution characteristics, laser Raman spectroscopy and mass inclusions analysis results show that the first stage I fluid H2O-CO2-CH4-H2S, the performance of To restore the environment; Stage II H2O-CO2-N2-O2, SO42-, Cl-, F-, performance oxidation environment, suggesting that fluid derived from magma. The inclusions petrographic and fluid inclusion showed that fluid from the early high temperature, high salinity, including CO2, H2O-NaCl-CO2system magmatic fluids in the ore-forming Stage I boiling and phase separation, accompanied by fluid boiling CO2escape of the temperature dropped, the process of atmospheric water salinity decreased to cause a lot of metal sulfide precipitation. In mineralization II and III of ore-forming system tends to open the fluid precipitation mixed with the gradual evolution of the late low-salinity fluid system in low temperature, depleted of CO2. H, O and S isotope results show that the mantle is involved in mineralization. The stable isotope studies of porphyry, biotite have also shown the same result, suggesting the mantle was the ore-forming source. According to the low denudation of Qiushuwan rock, the intact and large scale secondary enrichment zone, by contrasting with the other140Ma±large-super large deposits, Qiushuwan molybdenum (copper) deposit show the large-super large scale potential, yet the most important prospecting direction should be the deep porphyry, and apophysis, anticline, syncline, explosive pipe.Finally, based on three-dimensional model of ore deposit, alteration zoning, combined with remote sensing and geophysical interpretation, the target area was selectd, achieved a major prospecting breakthrough in the deep of Qiushuwan deposit.