地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
5期
751-761
,共11页
赵丕忠%王永%韩凤彬%陈正乐%陈柏林%江万%董法宪%吴德成
趙丕忠%王永%韓鳳彬%陳正樂%陳柏林%江萬%董法憲%吳德成
조비충%왕영%한봉빈%진정악%진백림%강만%동법헌%오덕성
大兴安岭北段%铅锌银矿%成矿流体%模式年龄%矿床成因
大興安嶺北段%鉛鋅銀礦%成礦流體%模式年齡%礦床成因
대흥안령북단%연자은광%성광류체%모식년령%광상성인
the northern Da Hinggan Mountains%lead-zinc-sliver deposit%ore-forming fluid%model age%deposit genesis
大兴安岭成矿带是中国五大重点有色金属成矿带之一,库伦迪-那吉河铅锌银矿床是其北段中部近年新发现的中-大型矿床之一,已控制的铅锌资源量达到中型规模,银资源量达到大型规模。矿区的流体包裹体和金属矿物S、Pb同位素研究表明,铅锌矿流体包裹体以气液包裹体为主,成矿温度为310~340℃,盐度小于6%,成矿流体密度为0.67~0.70g/cm3,推测成矿流体主要来自火山期后热液,后期有地表水的加入;成矿物质主要为深部来源(幔源),部分为中酸性岩浆期后流体萃取老地层中的成矿物质;根据Pb同位素单阶段演化曲线的模式年龄,推测为175Ma和138Ma两期成矿。综合分析认为,矿床成因类型为火山热液型。
大興安嶺成礦帶是中國五大重點有色金屬成礦帶之一,庫倫迪-那吉河鉛鋅銀礦床是其北段中部近年新髮現的中-大型礦床之一,已控製的鉛鋅資源量達到中型規模,銀資源量達到大型規模。礦區的流體包裹體和金屬礦物S、Pb同位素研究錶明,鉛鋅礦流體包裹體以氣液包裹體為主,成礦溫度為310~340℃,鹽度小于6%,成礦流體密度為0.67~0.70g/cm3,推測成礦流體主要來自火山期後熱液,後期有地錶水的加入;成礦物質主要為深部來源(幔源),部分為中痠性巖漿期後流體萃取老地層中的成礦物質;根據Pb同位素單階段縯化麯線的模式年齡,推測為175Ma和138Ma兩期成礦。綜閤分析認為,礦床成因類型為火山熱液型。
대흥안령성광대시중국오대중점유색금속성광대지일,고륜적-나길하연자은광상시기북단중부근년신발현적중-대형광상지일,이공제적연자자원량체도중형규모,은자원량체도대형규모。광구적류체포과체화금속광물S、Pb동위소연구표명,연자광류체포과체이기액포과체위주,성광온도위310~340℃,염도소우6%,성광류체밀도위0.67~0.70g/cm3,추측성광류체주요래자화산기후열액,후기유지표수적가입;성광물질주요위심부래원(만원),부분위중산성암장기후류체췌취로지층중적성광물질;근거Pb동위소단계단연화곡선적모식년령,추측위175Ma화138Ma량기성광。종합분석인위,광상성인류형위화산열액형。
The northern Da Hinggan Mountains area is one of the most important polymetallic metallogenic belts, where the Kulun-di-Najihe lead-zinc-silver deposit was discovered in recent years. Recent exploration shows medium to large scale reserves of lead and zinc resources and large scale silver resources. This paper mainly presents the researches on orebody characteristics and analytical results of fluid inclusions and stable isotopes in order to better understand the origin, metallogenic age and tectonic setting of the Ku-lundi-Najihe lead-zinc-silver deposit and further to make the exploration breakthrough of the lead-zinc-silver-polymetallic de-posits in north Da Hinggan Mountains. The analytical results show that fluid inclusions in the deposit mostly belong to typical gas-liq-uid inclusions, with the metallogenic temperature ranging from 310 to 340℃, the salinity of the ore-forming fluid lower than 6%, and the density being 0.67~0.70g/cm3, suggesting that the ore-forming fluid was probably derived mainly from the post-magmatic hydrothermal solution, with the addition of some surface water. Isotope analyses of S, Pb indicate that the ore-forming material was mostly derived from the depth with characteristics of mantle source, and the crust-mantle mixing post-magmatic hydrothermal fluid probably extracted ore-forming materials from old strata. The model age of Pb isotope single-stage evolution curve was used to con-strain the metallogenic age, and the results obtained show that this deposit was formed in two periods, i.e., about 175Ma and 138Ma re-spectively. It is held that the deposit belongs to a typical epithermal deposit related to post intermediate-acidic magmatism.