The Mineralography Characteristics And Its Genetic Significance Of The Luozigou Pb-Zn Deposit In Hanyuan Of Sichuan

The Luozigou Pb-Zn deposit is located in Hanyuan Pima township and Ganluo Heima township.It located at the junction of the Upper Yangtze archicontinent Kang Dian foreland thrust belt and Sichuan foreland thrust belt.Its tectonic attribution belongs to the Kangdian basement complex belt second-order tectonic unit under the Yangtze continental block first-order tectonic unit,Northern Maraha anticline,The exploration area of Ganluo-Xiaojiang Fault Zone,Ganluo-Butuo-Ningnan Pb-Zn metallogenic sub belt.The distribution of large,medium and small sized Pb-Zn deposits and ore.Regional stratigraphic development is complete,including Proterozoic Sinian?Paleozoic Cambrian?Ordovician?Silurian?Devonian?Permian?Mesozoic Jurassic and Cenozoic Quaternary.The development of geological structure,the main structure of the North-South parallel output.he main ore controlling structures in the area are the Maraha fault and Heima fault.It has a high background value of Pb,Zn,Ag elements.The Stratum?tectonic and Geochemical conditions all above laid a favorable foundation on geology conditions fo forming the Luozigou Pb-Zn deposit.Exposed strata in research area include Lower Ordovician?Upper Cambrian System?Upper Sinian Dengying Formation.The three section of the upper Dengying Formation-maidiping formation(Zbdm)are Regional Pb-Zn important ore bearing horizon.The general trend of strata is north to East,and Its Secondary structure is very developed.The main faults in the study area are the Pianma fault,the Jutianama fault(F1),the interlayer fracture zone and the secondary fault(fracture).Upper Sinian Dengying Formation maidiping formation(Zbdm)in the interlayer fracture zone circle two mineralized zone,a total of 6 ore bodies.The ore bodies are layered,layered-like and lenticular,Its top and bottom are carbonaceous shale.The ore bearing lithology is mainly siliceous dolomite,sandy dolomite and so on.The wall rock alteration mainly includes silicification,dolomitization,sulfide,brown iron mineralization,fading alteration and clay.The Ganluo-Xiaojiang Fault Belt Pb-Zn mine,carried out a large number of production work.It found a large number of minerals,but the overall level of research is low.Many ore bodies have been found,Its acale attain medium size and the prospecting potential is huge.But at present only part of the basic geological work,Some scholars have not carried out scientific research work on the deposit,There are still many problems to be solved.In this paper,according to the blank of previous research,develop the most basic and most important ore petrography characteristics are studied.Starting from ore type,structure,composition and mineral production order.From 7 aspects,including the source of ore-forming materials,the formation,type and characteristics of ore-forming fluid,the migration dynamics of ore forming fluid,the ore bearing structure,the mechanism of mineral crystal precipitation,the ore hosting structure and the metallogenic epoch,the metallogenic model was established.The main minerals in the study area are galena,sphalerite,pyrite,dolomite,calcite and quartz by light microscope observation.The ore structure is mainly composed of compact massive structure,disseminated structure,fine vein net vein structure,breccia structure and honeycomb structure,give priority to the massive block structure and disseminated structure.The ore structure in the study area is more diversified,and can be divided into four kinds of ore structures formed by crystallization,metasomatism,sedimentation and separation of solid solution.The ore-forming processes can be divided into sedimentary diagenetic period,hydrothermal mineralization period(euhedral crystal phase,galena sphalerite + galena + Pb phase,pyrargyrite vanadium phase),supergene oxidation stage three mineralization periods,five mineralization stages.To sum up,through the study of the ore petrography,we can conclude that the lead-zinc deposit in the Luozigou is a MVT Pb-Zn deposits,and its metallogenic model is as follows:During the Sinian to Early Cambrian tectonic movements resulted in large-scale migration of ore bearing fluids in the basement strata.Along the regional structure and the interlayer fracture zone in Dengying Formation dolomite.The accumulation is between the interlayer fracture zone and the secondary fracture.Due to changes in pressure and temperature,Pb?Zn metal elements enrich.The reproduction of a large number of algal organisms,bonding,adsorption of more metal elements.Then the element enrichment,the formation of industrial orebody.