| This article is study of a host-rock in the Huize super-large lead-zinc deposit..The study of host-rock alteration include of host-rock alteration types,alteration dolomite zonation and classification,determining hydrothermal alteration dolomite(HDT),microstructural of alteration dolomite,characteristics of near-ore the altered dolomitealteration dolomite of major elements and trace element migration features.It is the close relationship with the mineralization and ore body space.Sometimes it is basis of fluid penetration mineralization.(1)Alteration types of deposits hare dolomitization,calcite,silicification,argllization.Alteration types what hare strong relations with the orebody space are dolomitization,pyritization and fading.The altered rock hare horizontal zonation from C1d to C2w.(2)Altered dolomite of Baizuo Fm are control by NE faults.Altered dolomite hare the stronger and wider range alteration on the fracture.When fluid are flowing from the fracture to the wall rock,the wall-rock would has alteration and forming alteration zone.(3)The altered dolomite are "HDT",coarse-grained dolomite is a hydrothermal of dolomite,and it are significantly controlled by structure.(4)The ore-bearing dolomite hare microstructural that is low-temperature、low-stress、high strain rate.The microstructural reflectes that the wall-rock suffered strong tectonic stress and low temperature conditions.The dynamic recrystallization widely reflected that the wall-rock suffered strong stress and did not suffered hydrothermal fluids,sometimes dynamic recrystallization temperature is similar temperature with deposit formationt emperature(the calcite inclusions temperature 183 to 221℃).So dynamic recrystallization should be caused by stress when mineralization reflect the ore-forming fluids penetration the metallogenic characteristics("HZT" mode),and cause dynamic recrystallization.(5)Altered dolomite has large porosity that are the channel of transport mineral.The crystal cave of dolomite is the result of the hot brine fluid(or ore-forming fluid)account carbonates,it can reflect the strength and scope of the hot brine fluid(or ore-forming fluids)account carbonates.(6)Based on microscopically characteristic in the typical profile of mineralized alteration dolomite,mineral characteristics and microscopic structural characteristics,pyrite crystal shape and the occurrence,crystal cave fillings,fracture structure is an important symbol of distinguish mineral dolomite.(7)Compared mineralization of alteration dolomite with not-mineralized coarse-grained dolomite and dolomitic limestone,showing their major element and trace element features are diffirent.SiO2,TFe2O3,Al2O3,Pb,Zn,Ag,Cu,Cd are apparently geochemistry flag. |
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