發(fā)布時(shí)間：2018-11-23 09:41

【摘要】：七一牧場鉛鋅礦床位于興蒙造山帶東段，塔源—喜桂圖斷裂北西側(cè)的額爾古納地塊內(nèi)。區(qū)內(nèi)成礦地質(zhì)條件優(yōu)越，鉛、鋅、銀等礦產(chǎn)資源豐富。本文在收集區(qū)域地質(zhì)和礦區(qū)地質(zhì)資料的基礎(chǔ)上，通過野外地質(zhì)調(diào)研及測試分析綜合研究，并結(jié)合區(qū)內(nèi)同類型礦床的對比，對七一牧場鉛鋅礦床的成礦地質(zhì)背景、礦床地質(zhì)特征、礦床成因和礦化富集規(guī)律開展研究。 七一牧場礦床賦存于上侏羅統(tǒng)塔木蘭溝組火山巖地層中，礦化受NW向斷裂和構(gòu)造裂隙控制明顯，，礦體多呈脈狀和透鏡狀產(chǎn)出；礦石中金屬礦物以閃鋅礦、方鉛礦、黃銅礦、黃鐵礦等為主，并含有少量毒砂；金屬礦物主要呈自形晶及他形晶粒狀結(jié)構(gòu)、交代殘余結(jié)構(gòu)、交代溶蝕結(jié)構(gòu)、乳滴狀固溶體分離結(jié)構(gòu)等；礦體及圍巖發(fā)育中低溫?zé)嵋何g變，其中，硅化、黃鐵礦化、螢石化與礦化關(guān)系最密切；礦床的成礦過程分為熱液期（毒砂—黃鐵礦、石英—多金屬硫化物、石英—方解石階段）和表生期。 流體包裹體顯微測溫結(jié)果表明，該礦床石英—多金屬硫化物階段的成礦流體為中低溫（132~342℃）、低鹽度（0.5~11.9%NaCl eqv）、低密度（0.70~0.98g/cm3）的CO2-H2O-NaCl流體體系，流體的沸騰作用是七一牧場鉛鋅礦床元素沉淀的重要機(jī)制；石英—方解石階段的成礦流體為中低溫（160~280℃）、低鹽度（1.4~9.3%NaCleqv）、低密度（0.70~0.98g/cm3）的流體體系。 根據(jù)該礦床的成礦地質(zhì)條件、礦化特征和成礦物理化學(xué)條件，結(jié)合賦礦火山巖和礦石的稀土元素、微量元素和同位素特征，綜合判斷七一牧場鉛鋅礦床的成礦物質(zhì)來源于上地幔，并有殼源物質(zhì)的混入；礦石和火山巖可能具有相同物質(zhì)源區(qū)，是不同期次同源巖漿作用的產(chǎn)物。本文認(rèn)為，七一牧場鉛鋅礦床屬于賦存于中生代火山巖中與淺成—超淺成巖漿作用有關(guān)的中低溫?zé)嵋好}型礦床。 區(qū)域同類礦床綜合對比分析表明，塔木蘭溝組地層對該區(qū)的Pb、Zn、Ag等礦床的形成有利；區(qū)域性NE向斷裂控制了賦礦地層和鉛鋅礦床的空間分布，NW向和NWW向次級斷裂構(gòu)造具明顯導(dǎo)礦、容礦作用，特別是構(gòu)造交匯部位礦體規(guī)模增大，是熱液脈狀多金屬礦的有利成礦部位。 七一牧場礦床工業(yè)礦體在水平方向上呈透鏡狀產(chǎn)出，厚度、品位、產(chǎn)狀均在礦體的中間部位達(dá)到最大；垂向上，淺部礦體較深部的工業(yè)價(jià)值高。礦區(qū)內(nèi)北東向斷裂及其次級北西向隱伏斷裂構(gòu)造是該區(qū)主要的控礦容礦構(gòu)造，對成礦最為有利；中等程度的硅化形成的石英細(xì)脈是非常重要的找礦標(biāo)志；在地表形成次生鐵錳染和鐵帽，為該礦區(qū)找礦的直接標(biāo)志。
[Abstract]:The Qiyidao Pb-Zn deposit is located in the Erguna block in the north west of the Tayuan-Xiguitu fault in the eastern part of the Xingmeng orogenic belt. The ore-forming geological conditions in the area are superior, and lead, zinc, silver and other mineral resources are abundant. On the basis of collecting regional geology and geological data of mining area, through field geological investigation and test analysis, combined with the comparison of the same type of deposits in this area, the metallogenic geological background and geological characteristics of the Qiyizang Pb-Zn deposit are studied in this paper. The genesis of ore deposits and the regularity of mineralization enrichment are studied. The Qiyilangao deposit occurs in the volcanic strata of the Upper Jurassic Tamulangou formation. The mineralization is obviously controlled by the NW trending faults and structural fissures, and the orebodies are mostly vein-like and lenticular. Sphalerite, galena, chalcopyrite, pyrite and so on are the main minerals in the ore, with a small amount of arsenopyrite. The metallic minerals are mainly self-shaped and allotropic, metasomatic residual, metasomatic solution, emulsion droplet solid solution separation structure and so on. The hydrothermal alteration in the development of orebodies and surrounding rocks at low temperature is closely related to silicification, pyrite and fluorite mineralization. The ore-forming process of the deposit can be divided into hydrothermal period (arsenopyrite-pyrite, quartz-polymetallic sulfide), quartz-calcite stage and epigenetic stage. The microthermometric results of fluid inclusions indicate that the ore-forming fluids in the quartz-polymetallic sulphide stage of the deposit are of moderate and low temperature (132 ~ 342 鈩

本文編號：2351116