CAJ | 학술논문

野外地质调查结合室内显微镜研究和电子探针分析,发现西藏班公湖一怒江缝合带西段班公湖地区产有超基性岩型硫化镍矿和碳酸岩型硫化镍矿,中段班戈县产有超基性岩型Ni、Cr、Co多金属矿.这两个地区的含矿岩体均为超基性岩,大小从几十米到几百米不等,沿NWW方向展布,反映了蛇绿岩带对矿化的控制.岩体中普遍具有强烈的蛇纹石化,金属矿物组合简单,主要为硫镍矿和硫铁矿,呈微细粒浸染状分布,在野外露头和手标本上肉眼看不出矿化.由于该缝合带规模巨大,以基性.超基性岩为标志的蛇绿混杂岩数量多,分布广,因此,在该成矿带寻找超基性岩型硫化镍矿的找矿潜力很大.而碳酸岩型硫化镍矿化作为一种新的矿化类型,对其岩体成因和矿化机理的研究将具有探索造山带演化和指导地质找矿的双重意义.另外,无论是超基性岩型硫化镍矿还是碳酸岩型硫化镍矿,在西藏地区很少报道,这种矿化类型是班公湖.怒江成矿带上一个新的找矿方向.
야외지질조사결합실내현미경연구화전자탐침분석,발현서장반공호일노강봉합대서단반공호지구산유초기성암형류화얼광화탄산암형류화얼광,중단반과현산유초기성암형Ni、Cr、Co다금속광.저량개지구적함광암체균위초기성암,대소종궤십미도궤백미불등,연NWW방향전포,반영료사록암대대광화적공제.암체중보편구유강렬적사문석화,금속광물조합간단,주요위류얼광화류철광,정미세립침염상분포,재야외로두화수표본상육안간불출광화.유우해봉합대규모거대,이기성.초기성암위표지적사록혼잡암수량다,분포엄,인차,재해성광대심조초기성암형류화얼광적조광잠력흔대.이탄산암형류화얼광화작위일충신적광화류형,대기암체성인화광화궤리적연구장구유탐색조산대연화화지도지질조광적쌍중의의.령외,무론시초기성암형류화얼광환시탄산암형류화얼광,재서장지구흔소보도,저충광화류형시반공호.노강성광대상일개신적조광방향.
Based on field geological investigation combined with microscopic observation and electron microprobe ana lysis, the authors have revealed that there occur ultrabasic rock-type and carbonate-type nickel sulfide mineraliza tions in Bangong Lake area within the western segment of the Bangong Lake-Nujiang suture zone and ultrabasic type Ni, Cr, Co polymetallic mineralizations in Bange County within the middle segment of the suture zone. The ore-bearing bodies are all ultrabasic rocks whose sizes range from tens to hundreds of meters. The minera lizations are distributed in NWW direction and are controlled by the ophiolitic chaotic melange. The ore-bearing ultrabasic rock bodies have all experienced strong serpentinization and contain a simple metallic association con sisting mainly of NiS and FeNiS. The metallic sulfides assume a fine-grained dissemination, which cannot be discerned by naked eyes in field exposures and hand specimens. Taking into account the huge distribution of the ophiolitic melange marked by basic-ultrabasic rocks in the suture zone, the authors hold that the ultrabasic-type nickel sulfide mineralizations should have a large resource potential. Meanwhile, as a new mineralization type,the carbonate-type nickel sulfide mineralization has an indicative meaning both in orogenic evolution and in re gional prospecting. Moreover, both the ultrabasic-type mineralization and the carbonate-type nickel sulfide mi neralization are reported for the first time in Tibet. They hence constitute a new exploration target in the Ban-gong Lake-Nujiang metallogenic belt.