Mineralization Type And Prospecting Potential Of Copper Deposits In Yi Men Copper Mining Area

Yimen Tongchang copper is located in the Southern Kangdian rift on the Southwestern margin of the Yangze block, in the block of between the north-south-trend Yimen fault and Lvzhijiang fault. The surrounding mineral deposits/occurrences near the Tongchang copper deposit, has composed the a famous metallogenic province named Yimen copper ore field. Tongchang copper is a typical sedimentary reformation large acale copper deposit in the east metallogenic belt.Through the investigation and study about the deposit geology, C,O, S and Pb isotope geochemistry and discussed in this paper based on find the cutting relationship and the spatial-temporal distribution of copper mineralization.The result showed that, two kinds different copper mineralization had discovered in mining area. The’Deposition-Diagenesis’mineralization (Tongchang) is hosting in dolomite, Luo xue formation, strata-controlling and syngenetic deposit characteristics are obvious, the ore mineral mainly is bornite. The hydrothermal vein type copper mineralization (Da Jianshan) has the through strata characteristic, it is mainly hosting in Yin min formation, Luo xue formation and Ertouchang formation, formed in Jinning-Chengjiang movement period. The ore minerals mainly are chalcopyrite-calcite(barite), the chalcopyrite-quartz vein are distributed in parts of mining area. It is has the epigenetic deposit characteristic. The isotope compositions indicated that, the ore-forming material source of stratiform copper orebody (Tongchang) are originated from the ore beds and the nearby carbonate strata. This mineralization is typical sedimentary-diagenetic. Ore-forming fluid of Dajianshan vein ore is related to mantle-derived activity or deep magmatic activity; it belongs to crust-mantle mixed fluid with characterized by medium - low temperature and medium salinity. This phenomenon has shown that the deposit is formed in shallow seated environment with low-voltage and low-depth condition, it is typical magmatic hydrothermal deposit. This paper constructed metallogenic model for Tongchang deposit, and indicated the Yimen Tongchang copper deposit is a typically Sedimentary-Diagenetic type + Hydrothermal-Superimppsing polygenetic compound ore deposit.This two kinds mineralization composed different mineralization assemblages type areas in space. The sedimentary-diagenetic mineralized area is distributed between the South of No.15 exploration line and the West of No.16-15 exploration line, the deepening region of stratiform ore. The hydrothermal vein type mineralized areas are distributed in the Dajianshan-Tongchang region No.30 exploration line and the Xiaomashan ore block. The significantly superimposed combination area between sedimentary - diagenetic mineralization and hydrothermal vein mineralization is mainly localized in exploration Line 30-15. The metallogenic characteristics and the occurrence features of mineralization assemblages’ type areas are totally different.Based on the research of metallogenic regularity, this paper put the "The trinity of stratiform ore, stratiform-vein ore and vein ore" new prospecting thinking. According to the differences of mineralization assemblages type areas, the general principles of integrated prospecting work arrangements also put forward as the prospecting thinking of’rich ore prospecting in a poorly mineralized region’.