| The Songlin lead-zinc deposit is located in the Sichuan-Yunnan-Guizhou polymetallic metallogenic belt on the southwestern edge of the famous Yangtze block.The area is mainly controlled by the Zemuhe deep fault and the Ninghui large fault,and the metallogenic conditions are superior.The Songlin lead-zinc deposit was discovered in the 1950s.During this period,many related agencies have conducted intermittent exploration work,but it has not been publicly reported yet and lacks systematic research and summary work.In this paper,through a large number of field investigations,indoor data collection and collation,and experimental data analysis,the spatial distribution relationship between the stratum,ore body,and structure of the mining area is clarified.The type and structure of the ore are identified through the identification of light and thin slices under the microscope The structure has been studied in detail;the main trace elements and rare earth elements have been tested on the ore and the surrounding rock and the metallogenic age has been determined by the sphalerite Rb-Sr method;the geological characteristics and associated of the Songlin deposit are systematically summarized The enrichment law of elements;the understanding of the Songlin deposit is as follows:1.The Songlin deposit is mainly controlled by the Zemuhe deep large fault and the Ninghui large fault.The ore bodies are stored in the Ordovician Daqing Formation（O1d）,the Silurian Huanggexi Formation（S1hg）and the Silurian Daluzhai Group（S2d）,in which the Silurian Huanggexi Formation and Daluzhai Formation Dolomite are the main ore-bearing surrounding rocks,and the ore body output is mainly produced in the form of lamellar,lenticular,and network veins.2.The type and structure of the ore:the main sulfide minerals are:sphalerite,galena,pyrite;the main oxidized minerals are:galena,rhodochite,lead and vanadium.The structures are mainly vein-like,network-like,breccia-like,disseminated,block-like,and honeycomb-like structures;the main structures are strawberry-like structures,bay island-like structures,spontaneous crystal structures,and semi-automorphic-heteromorphic structures.There are eight kinds of crystal structure,inclusion structure,crumpled structure,broken structure,solid solution separation structure and so on.3.The metallogenic periods and stages are divided:the metallogenic period can be divided into hydrothermal metallogenic period and supergene period.Among them,the hydrothermal mineralization period can be divided into three stages,namely,quartz-zinc blende-galena stage,quartz-dolomite-zinc blende-galena stage,Quartz-calcite-sphalerite-galena stage.4.The source and environment of ore-forming materials are determined:the initial ratio of 87Sr/86Sr indicates that some of the ore-forming materials are derived from the crust;the low content of In in the ore and the ratio of Zn and Cd indicate that the deposit is formed at a lower temperature of.5.The metallogenic age of the deposit is determined:the Rb-Sr isotope dating is used to limit the metallogenic age of the deposit to（201.8±4.1）Ma,which was formed during the transition period from the late Indosinian to the early Yanshan.Mineral deposit.6.The occurrence status of different types of associated elements in Songlin lead-zinc deposits is different:associated trace elements such as Cu and Sb can be enriched in the form of independent minerals and quasi-homogeneous;Cd,In,Ga,Ge,etc.The associated sparse elements exist in a homogenous way.7.Explore the influence factors of sphalerite color and the regularity of enrichment with associated trace elements Cd,Cu,Sb,Ba,Ge.Cu,Sb,Ba,Ge and Cd in sphalerite show a good positive correlation,and the color of sphalerite in Songlin mining area gradually becomes darker with the increase of these elements.8.Determine the type of ore deposits.Based on the above research and analysis and comparison with the geological characteristics of other lead-zinc deposits in this area,the Songlin lead-zinc deposits are considered to be MVT deposits. |
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