Metallogenic Essential Factors And Prospecting Directions Of Fanshan To Baoweishan Area In Pinghe County, Fujian Province

Fanshan to Baoweishan area is located in the continental-volcanic rock basins vegetation covering of Pinghe Country in the east of Fujian Province. This area, together with the famous Zijinshan Mining Field, belongs to the Shanghang-Yunxiao NW-trending molybdenite and copper-gold polymetallic mineralization belt, which is am important prospecting target of Zijin-typed Cu-Au polymetallic deposit. However, the research area is not only serious recovered by vegetation, but also the extent of the previous exploration and survey research is relatively low. Although the study area is abundant in mineral resources, and has a very large ore-finding potential, studying on metallogenic factors of typical deposits about the Zijin-typed copper-gold polymetallic deposit is a blank work in this area. At present, the study area not only has not established a unified exploration theory prospecting methods based on the vegetation overlay environment of the continental-volcanic rock basins, but also is not clear of prospecting direction. Consequently, combined with former researcher, we select Fanshan to Baoweishan area to carry out research work on metallogenic essential factors and metallogenic prognosis, then the ore searching direction in this area is pointed out.The results of typical deposit show that, LA-ICP-MS zircon U-Pb dating has revealed the ages of one sample from the Baoweishan granite-porphyry is(98.1 ± 1.1) Ma. The host of the Baoweishan molybdenite deposit is the weakly silicified dacite crystal pyroclast tuff-lava in the bottom of the “Shimaoshan Group” formation. Its diagenetic age is(104.6 ± 1.1) Ma. Molybdenite Re-Os model age for the ore body is(95.2 ± 1.5) Ma, representing the first reported high precision ore-forming age in this area. The Re content of molybdenite indicates that the ore-forming materials are derived from mantle and crust. The comparative study approaches are employed to find that the geological background of mineralization in Fanshan and Zijinshan areas is similar. Both of the two areas have the similar ore-controlling structures, magmatic rock, lithofacies and alteration metallogenic essential factors. Combined with former researcher, we conclude that the quartz-alunitization and the silicification in the Fanshan volcano organization center are the important prospecting indications of Zijin-typed Cu-Au polymetallic deposit.Combined with former researchs, we conclude that Fanshan metallogenic prognosis area is promising for finding epithermal-mesotherm esothermal Cu-Pb-Zn deposit, porphyry Cu-Au polymetallic deposit and volcanic(-subvolcanic) hydrothermal Ag-Pb-Zn deposit. Laoyanshan to Sandoukeng to Dafengshan district of Baoweishan Metallogenic prognosis area is an advantage lacation to seek for porphyry molybdenum polymetallic deposit and volcanic(-subvolcanic) hydrothermal type Ag-Pb-Zn deposit. In addition, Xiaoqinshan Metallogenic prognosis area is the favorable regions for prospecting of epithermal-mesotherm esothermal Fe-Au polymetallic deposit. The NE and NW trending structure, ring volcanic structure and the complex contact zone are considered as the favourable metallogenic position. The geophysical and geochemical anomaly, wall-rock alteration, Metal mineralization are mainly distributed along the NE and NW trending structure, but the NW crack zones is the most important of transmitting ore and depositing ore structure in metallogenic prognosis area.