Metallogenic Regularity And Prospecting Direction Of Barite-fluorite Deposit In Southeast Sichuan

The barite-fluorite metallogenic belt of southeast Sichuan is one of the importantmetallogenic belt with barite and fluorite in China. They have134barite-fluoritedeposits and more than310ore bodies been found in this metallogenic, and thedistribution area of more than18000square kilometers. These deposits have a widedistribution, large ore body size, long extension length and many layers of ore. Basingon the study of the mineralization control condition, metallogenic material source andgenesis, this thesis summarizes the metallogenic regularities and puts forwardmetallogenic prediction of the metallogenic belt, in order to provide an importanttheoretical basis for the further exploration work about similar deposits in study areaand its adjacent area.The barite-fluorite deposits of southeast Sichuan controlled by the formation andthe structure. The host rocks of the barite-fluorite deposit are mainly the lowerordovician carbonate strata, and they are obvious stratabound ore deposits. Meanwhile,they controlled by NE fold-fault belts and NW belts strictly, NE fold-fault belts arepassage structures and barite-fluorite are all occurred in NW storage fault zone.REE geochemical analysis, δEu, δCe and Y/Ho results indicate that many oredeposits (points) in barite-fluorite metallogenic belt of southeast Sichuan havecontemporaneous and homologous characteristics, and ore-forming materials offluorite and barite come from different stratums, they formed during the same periodbut came from different sources. Eu and Ce anomaly of ore Prove metallogenicenvironment is high oxygen fugacity open system. According to Tb/Ca-Tb/Larelationship diagram and La/Yb-REE relationship diagram display that barite-fluoritedeposits of the study area are hydrothermal origin, and have no relationship withmagmatic activity, metallogenic materials from sedimentary stratum.Barite and fluorite mineralization in the study area belongs to the middle-lowtemperature ore deposit. The temperature in the ore-forming process is reduced. Fromthe Hydrogen and oxygen isotopic data collected, it shows that the source ofhydrothermal fluid in the study area is multi-source, which is mainly from theformation water, meteoric water and sea water.According to the studies of isotope and trace elements, Cambrian-ordoviciancarbonate strata can provide enough Ca for mineralization, the source of the Ca formulti-source. Main source layer of Ba is the lower Cambrian Niutitang group. the upper sinian doushantuo group-the Lower Cambrian Mingxinsi group formation canprovide source for ore-forming materials F in the study area. the ore-forming materialof S is mainly from the Cambrian evaporates. According to the fluorite Sm-Ndisochron age of Huoshiya barite-fluorite deposit is104±14Ma, indicates that themetallogenic era of study area mainly for late yanshanian movement.According to the ore deposit geological characteristics, ore-controlling factorsand metallogenic mechanism study, these deposits belong to low temperaturehydrothermal genesis-fault zone filling metasomatic deposits. Determinedmetallogenic prediction marker by the studes of formation, structure, wall rockalteration, remote sensing, etc, the prospecting target areas are delineated, and pointedout the direction for further ore prospecting the barite-fluorite deposits.