CAJ | 학술논문

内蒙古毕力赫金矿床(Ⅱ号带)是全国危机矿山接替资源勘查获得重大突破的矿床之一,由武警黄金地质研究所勘查发现(2006-2008年).矿区位于华北板块北缘叠接俯冲带南部华北板块一侧的陆相火山岩盆地中.该矿床有如下主要特点:(1)矿体呈隐伏状态(距地表1～40 m)产出于隐伏的燕山期花岗闪长斑岩体接触带内.并以内接触带为主;(2)矿体规模大(目前控制长500 m,最宽处300 m,最窄处约40 m.最大厚度128.17 m,最小厚度10.53 m,平均厚度52.85 m),品位高(平均4.5×10~(-6),最高52.76×10~(-6)),单个矿体资源量达20 t以上;(3)矿石为蚀变的花岗闪长斑岩和火山岩型.前者具有典型的单向固结结构(UST).金属矿物以黄铁矿、黄铜矿、辉钼矿等为主,但含量低(小于1%),金主要赋存于蚀变形成的团块状或细脉状石英中;(4)围岩蚀变以钾化、硅化、绢云母化、高岭土化、青磐岩化等为主,具有富金斑岩型铜矿床的分带特征;(5)成矿温度明显分为两个区间.早期石英流体包裹体均一温度大于550℃,为含矿热液沸腾结果;中晚期温度变化在108～375℃,平均值为194℃.初步研究表明,该矿床应为独立的大型高品位斑岩型金矿床,在华北板块北缘地区为首次发现,具有典型性和代表性.对于区域相似地质环境内类似矿床的寻找和勘查具有重大示范意义.
내몽고필력혁금광상(Ⅱ호대)시전국위궤광산접체자원감사획득중대돌파적광상지일,유무경황금지질연구소감사발현(2006-2008년).광구위우화북판괴북연첩접부충대남부화북판괴일측적륙상화산암분지중.해광상유여하주요특점:(1)광체정은복상태(거지표1～40 m)산출우은복적연산기화강섬장반암체접촉대내.병이내접촉대위주;(2)광체규모대(목전공제장500 m,최관처300 m,최착처약40 m.최대후도128.17 m,최소후도10.53 m,평균후도52.85 m),품위고(평균4.5×10~(-6),최고52.76×10~(-6)),단개광체자원량체20 t이상;(3)광석위식변적화강섬장반암화화산암형.전자구유전형적단향고결결구(UST).금속광물이황철광、황동광、휘목광등위주,단함량저(소우1%),금주요부존우식변형성적단괴상혹세맥상석영중;(4)위암식변이갑화、규화、견운모화、고령토화、청반암화등위주,구유부금반암형동광상적분대특정;(5)성광온도명현분위량개구간.조기석영류체포과체균일온도대우550℃,위함광열액비등결과;중만기온도변화재108～375℃,평균치위194℃.초보연구표명,해광상응위독립적대형고품위반암형금광상,재화북판괴북연지구위수차발현,구유전형성화대표성.대우구역상사지질배경내유사광상적심조화감사구유중대시범의의.
The Bilihei gold deposit(No.II ore zone) in Inner Mongolia,found by Gold Geological Institute of CAPF in 2006-2008,is one of the fatal breakthrough deposits supported by the Project of Supersedable Resource Prospecting of Critical Mines in China.It is located in the Mesozoic(Jurassic) continental facies volcanic basin on the northern margin of North China plate.The main characteristics of the deposit are as follows:(1) the concealed ore body occurs in the contact zone(mainly in the inner-contact zone) between granodiorite porphyry and volcanic rocks;(2) a large ore body 500m long,300m wide and averagely 52.85m thick was identified,which contains 21916 kg Au at the average grade of 4.5×10~(-6)(the highest grade being 54.76×10~(-6));(3) ores can be classified into altered granodiorite porphyry type and andesite porphyrite type,with the former type having typical unidirectional solidification texture(UST).There are only small amounts(<1%) of metallic minerals,such as pyrite,chalcopyrite and molybdenite,in the ore;gold mainly occurs in lumpy or veinlet quartz formed during alteration;(4) just like gold-rich porphyry copper deposits,the alteration shows obvious ring-shaped zoning;the concentric alteration zones from the inner part outwards and from early to late stages are successively the K-silicate zone,the quartz-sericite zone,and the propylitic zone;the structure-controlled argillic alteration locally occurs as patches,superimposed by other alteration zones;(5) the early ore-forming stage has very high temperature(>550℃),and the temperature of the middle-late stage is 108～375℃,194℃ on average.It is concluded that this deposit is a large-sized and high-grade independent and concealed porphyry Au deposit and is the first deposit of this kind discovered on the northern margin of North China plate.