矿物岩石地球化学通报
礦物巖石地毬化學通報
광물암석지구화학통보
BULLETIN OF MINERALOGY PETROLOGY AND GEOCHEMISTRY
2015年
3期
564-570
,共7页
闫国强%丁俊%黄勇%李光明%王欣欣%戴婕%白景国
閆國彊%丁俊%黃勇%李光明%王訢訢%戴婕%白景國
염국강%정준%황용%리광명%왕흔흔%대첩%백경국
辉钼矿%稀土元素%微量元素%成矿流体%西藏
輝鉬礦%稀土元素%微量元素%成礦流體%西藏
휘목광%희토원소%미량원소%성광류체%서장
molybdenite%rare earth elements%trace elements%ore-forming fluid%Tibet
为厘清努日铜钼钨矿床的成矿时代，以矿床中的辉钼矿为研究对象，用 ICP-MS 分析方法，开展了稀土元素和微量元素地球化学研究。结果显示，辉钼矿具有典型的轻重稀土分馏、轻稀土元素（LREE）富集的右倾配分模式，辉钼矿稀土元素具有强烈的 Ce 负异常和 Eu 负异常，前者可能为成矿流体本身具有高温高氧逸度导致，后者可能是与矽卡岩矿化有密切关系的黑云母花岗闪长岩浆在分离结晶过程中大量的斜长石晶出引起的，同时岩体蚀变过程中对成矿流体体系亏损铕有一定贡献。辉钼矿中 Pb、Ba、V、Ni、Sr、Rb 含量相对较高，U、Th 含量非常低，Hf／Sm、Th ／La 远小于1，Nb ／La 远大于1，表明成矿流体早期以富 F 的来自于深部幔源的岩浆热液为主，而Y ／Ho、Zr／Hf、Nb ／Ta 变化范围存在不同幅度的差异。表明主成矿期成矿流体在该阶段不同程度的混入了部分外来流体而富 Cl，但总体特征仍以早期成矿流体为主。
為釐清努日銅鉬鎢礦床的成礦時代，以礦床中的輝鉬礦為研究對象，用 ICP-MS 分析方法，開展瞭稀土元素和微量元素地毬化學研究。結果顯示，輝鉬礦具有典型的輕重稀土分餾、輕稀土元素（LREE）富集的右傾配分模式，輝鉬礦稀土元素具有彊烈的 Ce 負異常和 Eu 負異常，前者可能為成礦流體本身具有高溫高氧逸度導緻，後者可能是與矽卡巖礦化有密切關繫的黑雲母花崗閃長巖漿在分離結晶過程中大量的斜長石晶齣引起的，同時巖體蝕變過程中對成礦流體體繫虧損銪有一定貢獻。輝鉬礦中 Pb、Ba、V、Ni、Sr、Rb 含量相對較高，U、Th 含量非常低，Hf／Sm、Th ／La 遠小于1，Nb ／La 遠大于1，錶明成礦流體早期以富 F 的來自于深部幔源的巖漿熱液為主，而Y ／Ho、Zr／Hf、Nb ／Ta 變化範圍存在不同幅度的差異。錶明主成礦期成礦流體在該階段不同程度的混入瞭部分外來流體而富 Cl，但總體特徵仍以早期成礦流體為主。
위전청노일동목오광상적성광시대，이광상중적휘목광위연구대상，용 ICP-MS 분석방법，개전료희토원소화미량원소지구화학연구。결과현시，휘목광구유전형적경중희토분류、경희토원소（LREE）부집적우경배분모식，휘목광희토원소구유강렬적 Ce 부이상화 Eu 부이상，전자가능위성광류체본신구유고온고양일도도치，후자가능시여석잡암광화유밀절관계적흑운모화강섬장암장재분리결정과정중대량적사장석정출인기적，동시암체식변과정중대성광류체체계우손유유일정공헌。휘목광중 Pb、Ba、V、Ni、Sr、Rb 함량상대교고，U、Th 함량비상저，Hf／Sm、Th ／La 원소우1，Nb ／La 원대우1，표명성광류체조기이부 F 적래자우심부만원적암장열액위주，이Y ／Ho、Zr／Hf、Nb ／Ta 변화범위존재불동폭도적차이。표명주성광기성광류체재해계단불동정도적혼입료부분외래류체이부 Cl，단총체특정잉이조기성광류체위주。
Geochemical characteristics of rare earth and trace elements in the molybdenite were studied with ICP-MS method to identify the metallogenic epoch of the Nuri Cu-Mo-W Deposit.The results showed that the light and heavy REEs were fractionated obviously,molybdenite was low with negative cerium and europium anomalies that was characterized by enrichment in light REE.The former found ore-forming fluid had the characteristics of high temperature and high oxygen fugacity,and the latterwas caused by plagioclase crystal in the process of biotite monzonitic granite magma separation and crystallization which had close contact with the skarn,meanwhile gain the contribution from the process of rock alteration. The contents of Pb,Ba,V,Ni,Sr and Rb were relatively high but contents of U and Th were very low.The enrichment indexes of LREE,Hf/Sm and Th /La were far less than 1 while that of Nb /La was greater than 1,indicating that the man-tle-derived ore-forming fluid was F-rich in the early,and that the Y /Ho,Zr /Hf and Nb /Ta varied differently.All of which indicated that,in the main metallogenic epoch,the ore-forming fluid was mixed with some external Cl-rich fluid but still showed the characteristic of the early stage fluids.
