Study On Metallogenic Regularity And Prospecting Prediction Of Zinc And Copper Deposit, Lame,Dachang,Guangxi

The Danchi metallogenic belt is an important nonferrous metal metallogenic belt in china, whose tectonic uplift is located in the southwest margin of Jiangnan old land. You-jiang Danchi fold belt in the edge of the regenerated geosynclines, Composite part of Paleotethys tectonic domain and the Pacific tectonic domain.the host a NW-SE direction to extend the panhandle. Belt from north to south, crossing faults in the NW and NE parts of three large uplift belts, there are three large tin polymetallic ore fields: Mangchang, Dachang and Wuxu, at the periphery there are Yilan and Mayang mercury mine.Lame zinc-copper deposit is located in the central uplift zone of Guangxi Dachang tin polymetallic metallogenic belt, genus of Dachang tin-polymetallic ore field in. Complex structure is a NW trending fold belt, central to the ring structure belt. Faults are mainly from SN, NW and NE. On the damage effect strong wall rock alteration, and with obvious zonation, the complex relationship between type and skarn copper, zinc, silver mineralization is closely, ore bodies often produced in or near the, has the prospecting significance of alteration.The deposit both skarn-type zinc-copper mine, and there is a medium-low hydrothermal tungsten-antimony mineralization. Skarn-type zinc-copper mineraliza-tion can be divided into two groups according to the characteristics of occurrence: stratiform mineralization and vein mineralization; and can be divided into three types: gently inclined stratiform zinc copper mineralization, steeply dipping fissure filling-account of the fine stockwork mineralization, steeply inclined vein mineralization.Based on the previous studies and date, and through studying the geological background, mining area, and geological characteristics of deposit, summed up the ore-controlling factors and metallogenic law of zinc-copper deposit. According to the theory of the genesis of the deposit ore-controlling factors and prospecting criteria, with geophysical, geochemical for deep prospecting prediction.Through the above research, made the following understanding:1. The mineralization of Lame zinc copper mine is divided into two minera liza-tion period and the five stages of mineralization: (1) The skarn rock type zinc (copper) mineralization period:the early stages of sulphide (iron, copper stage); and the late stages of sulphide (pb-zn phase);(2) Antimony-Tungsten mineralization period:scattered disseminated scheelite mineralization stages, scattered disseminated stibnite mineralization stage and vein stibnite mineral-calcite mineralization stage.2. ore-forming material source:Based on the analysis of characteristics of ore minerals, Sulfur isotope, lead isotope and REE, reflect the ore-forming materials derived from magma, it has a close relation with the Longxianggai granite body.(1) Sulfur isotopic characteristics:Because of Homogeneous sulfur isotopic composition of sphalerite and pyrite, so the deposit is of the same sulfur source, The834S deposit sulfide values range between-2.1%o～+2.0%o, it is characteristics of mantle source of sulfur.(2) Pb isotopic characteristics:The stable variation of lead isotope compositions of stratiform ore and strip mine ore, and the two has the similarity, show a more stable source of lead, and has the same source of lead, because of most points in the crust and oregenic belt evolution curve. So the lead mainly come from upper crust and ore-genic belt, there are mixed with a small amount of mantle lead. Stratiform ore and strip mine ore mineralization is formed in the same, and there is a certain regulari-ty, the age range is190Ma-279Ma, strip mine ore and stratiform ore forming at the same time, or rather to activation by stratiform ore later.(3) Characteristics of rare earth elements:Characteristics of rare earth elements in the stratiform and vein orebody is consistent, show that the material source and similar evolution process, but its skarn REE distribution curves of different, explained that the mineral is not derived from the strata. Because of the δ Eu values were less than1of all samples, so Eu is negative anomaly which has the typical characteristics ofmagmatic origin. The internal ore fractionation of early earth elements varied strongly, that shows a two different mineralization stages.3. Study on metallogenic regularity:Through comprehensive analysis of the regional tectonic position A deposits, the spatial relationship between gold deposits and granitic pluton, the output state of ore deposit, dividing the periods of mineralization, and the source of metallogenic material, combining with the former research, the ore deposits formed by the granite magma intrusion action contro, intrusion of magma can bring a lot of minerals for their, and provides enough energy, the space place ore body is controlled by granite magma intrusion dynamic condition, at magma intrusion early, because the D32is strongly thermal dynamic role, resulting in a plastic state, to fold and interlayer sliding, and appear stratiform and stratoid ore body, and the surrounding recrystallization,that appear early sulfide mineralization stage. In the late magmatic hydrothermal alteration stage, cooling pluton, under the power action of D32produces a lot of cracks, the hydrothermal alteration of layered and stratiform like orebody, the activation and formation of ore minerals along thefrac-ture vein filling that appears late sulphide stage. In other words, navariety of factors metallogenic magma tic rocks, Favorable litho logy and ore control tectonic factors possess the metal-logenic condition formed Lamo zinc copper deposit.4. Deep prospecting:According to the area surrounding the geological, explora-tion prediction, deep in the No.(91-1) ore body, the No.(28-2) ore body, the No.94ore body, the No.95ore body, the No.96ore body extension was predicted, and calculate forecast district of the ore body resourcesusing parallel section method: No.(91-1) ore body, volume of236×104tons of ore body; No.(28-2) ore body, volume of297×104tons of ore body; No.94ore body, volume of24×104tons of ore body; the amount of metal zinc and copper0.85×104tons; No.95ore body, volume of219×104tons of ore body; the amount of metal zinc and copper9.58×104tons; No.96ore body, volume of44×104tons of ore body; The amount of metal zinc and copper2.61×104tons. Five a total volume of820×104tons of ore deposit, the Lame mineral rights within329x104tons.5. Side prospecting prediction:five target area were circled when comprehensive analysis of geology, geophysical and chemical was done, it is of the target area of Dingbian, the Ⅰ target areas is Xiangshuiwan target area (Ⅰ-1), Longxianggai target area (Ⅰ-2); the II target areas are three, southwest of Dafulou target area (Ⅱ-1), Mojiaping-Tiebanshao target area (Ⅱ-2), and southeast of Shanmuchong target area (Ⅱ-3).