發(fā)布時(shí)間：2018-11-06 08:51

【摘要】：南秦嶺山陽-柞水礦集區(qū)大地構(gòu)造位于秦嶺復(fù)合造山帶東段北部晚古生代裂陷帶中,構(gòu)造帶呈近東西向帶狀展布,構(gòu)造演化復(fù)雜,巖漿活動(dòng)強(qiáng)烈,王家坪金礦床位于山陽-柞水礦集區(qū)南界山陽-鳳鎮(zhèn)斷裂以南,該區(qū)構(gòu)造活動(dòng)頻繁,區(qū)內(nèi)礦床組合復(fù)雜多樣,王家坪金礦是該區(qū)少有的卡林型金礦。本文依托“十二五”國家科技支撐計(jì)劃課題“陜西山陽-柞水礦集區(qū)斑巖銅鉬金礦深部找礦模式及勘查技術(shù)集成與示范”,選擇王家坪金礦床作為研究對(duì)象,開展了詳細(xì)的地質(zhì)調(diào)查,對(duì)其地質(zhì)特征、巖礦石地球化學(xué)、H-O-S穩(wěn)定同位素等進(jìn)行研究。探討了其成礦物質(zhì)、成礦流體的來源與性質(zhì)及其成礦機(jī)制。主要取得以下成果:(1)王家坪金礦賦存于區(qū)內(nèi)泥盆系星紅鋪組中,控礦構(gòu)造為東西向斷裂,礦體主要沿破碎蝕變帶分布,礦化類型為卡林型;礦石中黃鐵礦、褐鐵礦、雄(雌)黃等載金硫化物主要呈浸染狀分布;其中主要載金礦物為黃鐵礦;圍巖蝕變以黃鐵礦化、硅化、去碳酸鹽化、雄(雌)黃化、毒砂化、碳化、泥化、鐵碳酸鹽化為主,局部可見輝銻礦化、黃銅礦化,礦區(qū)外圍可見白鎢礦化;主成礦階段可分為三個(gè)礦化階段:石英-方解石-黃鐵礦階段、方解石石英-金-多金屬硫化物階段、石英-方解石-雌黃-雄黃階段。(2)通過對(duì)成礦期的流體包裹體測(cè)溫工作,可知王家坪金礦包裹體均一溫度為低溫(100-120℃),成礦期鹽度范圍為15.96wt%NaCl。成礦期流體密度平均值為1.06g/cm~3,成礦壓力范圍平均值為133MPa。王家坪金礦的成礦深度為4.9km,礦床屬于低溫?zé)嵋旱V床。(3)黃鐵礦稀土元素、微量元素測(cè)試結(jié)果顯示:王家坪金礦不僅圍巖、礦石稀土配分曲線型式及特征相似,且它們中黃鐵礦的稀土元素配分曲線型式及特征及圍巖與微量元素V、Sc“谷”和Co、Ni“峰”及整體曲線分配形式也較為相似,這指示圍巖是主要的成礦物質(zhì)來源。而微量元素中Y/Ho比值及Tl的異常高值,則指示來自殼幔深部的組分在成礦過程提供了部分成礦物質(zhì)。(4)H-O同位素結(jié)合微量元素結(jié)果顯示成礦流體在富Cl流體和富F流體性質(zhì)之間的改變,指示在整個(gè)成礦階段成礦流體具有多期演化特征。而S同位素的分布,則進(jìn)一步證明成礦物質(zhì)中有深源物質(zhì)的加入。(5)綜合區(qū)域資料并結(jié)合王家坪金礦地質(zhì)特征,推斷該礦床的成礦機(jī)制為:區(qū)域內(nèi)的強(qiáng)烈的構(gòu)造運(yùn)動(dòng)使圍巖地層中原始分散狀態(tài)的金不斷活化遷移富集。地溫及構(gòu)造應(yīng)力的增高,使沉積建造釋放出大量的熱脫水及地層封存水。這些流體在熱與力的作用下沿構(gòu)造空隙流動(dòng)萃取圍巖成礦物質(zhì),同時(shí)與由殼幔深部向地殼淺部移動(dòng)的深源流體相混合,導(dǎo)致含礦熱液物質(zhì)成分受到地殼深部流體攜帶的物質(zhì)混染并發(fā)生流體性質(zhì)改變。最終,在大氣降水參與下,含礦熱液沿各級(jí)斷裂滲流沉淀而成礦,形成現(xiàn)今的王家坪金礦。
[Abstract]:The tectonics of Shanyang-tussah Ore accumulation area in the South Qinling Mountains are located in the late Paleozoic rifting belt in the northern part of the Qinling complex orogenic belt. The tectonic belt is distributed in the near east-west direction, the tectonic evolution is complicated, and the magmatic activity is strong. The Wangjiaping gold deposit is located in the south of the Shanyang-Fengzhen fault in the southern boundary of Shanyang-tussah Ore concentration area, which is characterized by frequent tectonic activity and complex and diverse ore deposit assemblages. The Wangjiaping gold deposit is a rare Carlin type gold deposit in this area. Based on the "12th Five-Year Plan" of the National Science and Technology support Program, "the deep prospecting model and exploration technology of porphyry copper-molybdenum gold deposits in Shanyang-tussah Ore concentration area, Shaanxi Province", this paper selects the Wangjiaping gold deposit as the research object. The geological characteristics, geochemistry of rock and ore, and H-O-S stable isotopes are studied in detail. The source, properties and metallogenic mechanism of its ore-forming material, ore-forming fluid are discussed. The main achievements are as follows: (1) the Wangjiaping gold deposit occurs in the Xinghongpu formation of Devonian system, the ore-controlling structure is east-west fault, the orebody mainly distributes along the broken and altered zone, and the mineralization type is Carlin type; Pyrite, limonite, male (female) yellow and other gold bearing sulfides are mainly disseminated in ore, among which pyrite is the main gold bearing material. The main alteration of surrounding rock is pyrite, silicification, decarbonization, male (female) yellowing, arsenopyrite, carbonization, mudding, iron carbonization, local antimony mineralization, chalcopyrite, and scheelite mineralization in the periphery of the mining area. The main metallogenic stage can be divided into three stages: quartz calcite pyrite stage calcite quartz gold polymetallic sulfide stage. Quartz-calcite, realgar and realgar stage. (2) the homogenization temperature of inclusions in Wangjiaping gold deposit is low temperature (100-120 鈩，

本文編號(hào)：2313807