Organic Mineralization Of The Jinding Lead-Zinc Ore Deposit

As viewed from the organic mineralization, this paper studies the genesis of the Jinding Pb-Zn deposit of Yunnan province, which is based on the theories such as the geology of ore deposit, organic geochemistry, the geology of oil and gas and geological statistics, and uses the methods or the measures of physical property analysis, GC-MS-MS analysis, neutron active analysis and electron microprobe analysis. The main conclusions are drawn as follow:(1) The sedimentary environment of the ore-hosted strata is investigated in this study based on evidences of lithology, color, granularity analysis, facies indictor, geochemical data and so on. Research has showed that the lower ore-hosted strata probably deposited in evaporate salty lake. It is believed that the supper deposits be not able to be formed in this geological condition for its shallow depth and rapid sedimentary rate. But the overthrusting strata make it become possible. First, Huakaizuo Formation(J₂h) strata is better cover for low permeability and high displacement pressure, and second, Jingxing Formation(K₁j) strata is better reservoir for high porosity and permeability, and a better interconnecting. The intra-basin strata system is composed of Yunlong Formation(Ey). upper member of Yunlong Formation(Ey^a) is good barrier for its low permeability and a bad interconnecting, but Lower member of Yunlong Formation(Ey^b) is better host layer.(2) By analyzing the features of ore-forming fluid, a conclusion is drawn that there is multiperiodity of organic inclusion, and the ore forming fluid of the mineralization stage is organic fluid with a lot of organic matter, there also is organic matter of ore forming fluid of the post mineralization stage.The mode of occurrence of anthraxolites is comprised of nervation, squama, disseminated type, eyeball-shaped type, cystiform and cement by field observing, and the following anthraxolites can be observed by microscope such as the anthraxolite between or among particles, fracture anthraxolite, dissolved pore anthraxolite and patch of anthraxolite. These anthraxolites play a different role during the process of the Jinding Pb-Zn deposit formation. Of all these anthraxolites the cement anthraxolite, the vein anthraxolite and part of the squama anthraxolite are most important to this deposit, during the process of these anthraxolites organic cements can dissolve and move ore-forming elements and result in theirs reducing. eyeball-shaped type and cystiform anthraxolites are formed latterly, so these anthraxolites can play an influential role to the Jinding Pb-Zn deposit. The mineralization of almost all disseminated anthraxolite was characterized by reducing.The organic molecule information shows that the biological source is mainly bacterium and algae, even possibly combine some vegetable. The deposit is formed in a reductive environment, and the higher salinity of sedimentary environment.(3) Studies on the correlation between organic matter and Jinding Pb-Zn deposit, the results...