Ore-controlling Structure Characteristics And Metallogenic Prediction Of Fozichong Pb-Zn Ore-field

Fozichong Pb-Zn ore-field ,which is one of the important Pb-Zn ore deposit in South China,is at the boundary of Cenxi city and Cangwu county, both of which are in the southeast of Guangxi province. The associated elements are Ag,Cd and copper. The reserve of silver can be up to the one of medium-large deposit. Since it produced in 1969, the ore above the level of 300m is exhausted. The ore body is smaller and pinched in deep. It is urgent to prospect outside the ore field. Based on the regional geological setting, ore deposit geological features and ore-controlling structures, the author digitalized the 1:10000 geological map of the mine area,1:10000 geochemical map and 1:10000 gravity-magnetic map; built a data base ;re-extracted and optimized the information of geology, geophysics and geochemistry; determined the criteria for ore prospecting ;set up mathematical model. Combined with the data of geology, geophysics and geochemistry, the author predicted the potential of the ore in a synthetical information way by the weight-calculating module of ArcGIS.The main results are as follows:â‘ The host structures of the north of Fozichong deposit are in northeast and north-northeast orientations. The south ore bodies are in the joints of northeast (or north northeast) faults and northwest faults.â‘¡Fozichong deposit is controlled by structures, strata and magmatite. It is a typical trinity combination of limestone (argillaceous limestone, calcium siltstone) strata, Yanshanian granitic magma and NNE (NE) faults. The superimposition of the three elements is the key factor of the production of favorable time-space.â‘¢The metallogenic substance of Fozichong deposit are mainly from magmatic hydrothermal, partly from the host rock. The metallogenic process is of many stages.â‘£The author delineated three targets by GIS technique using synthetical information, which were Liutang-Tongmaoding-Longshudong,Niuwei and huidi-Lezhai-Wulonggang. In the view of geological characters, geophysical and geochemical characters and mineralization character, the author verified the targets and proved that there is a big potential both in deep and outside of Fozichong mine area.