CAJ | 학술논문

报道了西南印度洋中脊47°E～55°E洋脊段热液区硫化物中 He、Pb和 Cu同位素特征，探讨了热液硫化物成矿物质来源特征。结果表明：硫化物N（3 He）/N（4 He）值变化范围较大（R/R a＝0.85～7．02），显示洋中脊玄武岩和海水对He来源具有不同贡献，硫化物中He主要来源于洋中脊玄武岩，也有部分放射性成因 He的混入；热液硫化物 Pb 同位素比值变化范围很小（N （206 Pb）/N（204 Pb）＝18．196～18．239，N （207 Pb）/N （204 Pb）＝15．479～15．490和 N （208 Pb）/N （204 Pb）＝37.951～38．023），与西南印度洋中脊玄武岩 Pb 同位素比值较大的变化范围相比，热液流体循环过程中Pb同位素发生了明显均一化；硫化物单矿物 Cu同位素组成均为正值（δ（64 Cu）＝（0.02～0．52）×10-3），显示西南印度洋中脊热液硫化物呈现略微富集 Cu重同位素特征；西南印度洋中脊热液硫化物中 He、Pb和 Cu同位素记录了热液喷口流体和金属源区特征，热液硫化物成矿物质主要来源于洋中脊玄武岩和海水，但明显经历了热液流体再循环和后期改造过程。
보도료서남인도양중척47°E～55°E양척단열액구류화물중 He、Pb화 Cu동위소특정，탐토료열액류화물성광물질래원특정。결과표명：류화물N（3 He）/N（4 He）치변화범위교대（R/R a＝0.85～7．02），현시양중척현무암화해수대He래원구유불동공헌，류화물중He주요래원우양중척현무암，야유부분방사성성인 He적혼입；열액류화물 Pb 동위소비치변화범위흔소（N （206 Pb）/N（204 Pb）＝18．196～18．239，N （207 Pb）/N （204 Pb）＝15．479～15．490화 N （208 Pb）/N （204 Pb）＝37.951～38．023），여서남인도양중척현무암 Pb 동위소비치교대적변화범위상비，열액류체순배과정중Pb동위소발생료명현균일화；류화물단광물 Cu동위소조성균위정치（δ（64 Cu）＝（0.02～0．52）×10-3），현시서남인도양중척열액류화물정현략미부집 Cu중동위소특정；서남인도양중척열액류화물중 He、Pb화 Cu동위소기록료열액분구류체화금속원구특정，열액류화물성광물질주요래원우양중척현무암화해수，단명현경력료열액류체재순배화후기개조과정。
The source of hydrothermal fluid and metals of deposit is very important to understand mineralization of hydrothermal sulfide on the mid-ocean ridge. He, Pb and Cu isotopic characteristics of hydrothermal sulfide from the section of ocean ridge (47°E-55°E)of Southwest Indian Ridge were analyzed,and the characteristics of mineralization sources of hydrothermal sulfide deposit were discussed.The results show that the range of N(3 He)/N(4 He)of sulfide is wide with the R/R a of 0.85-7.02,so that the contributions of mid-ocean ridge basalt (MORB) and seawater to the sources of He are different,and the main source of He of sulfide is MORB with radiogenic He mixing partially;the ranges of Pb isotopic ratios of sulfide are limited with N(206 Pb)/N(204 Pb)of 18.196-18.239,N (207 Pb)/N (204 Pb)of 15.479-15.490 and N (208 Pb)/N(204 Pb)of 37.951-38.023,so that compared with the wide ranges of Pb isotopic ratios of basalt from Southwest Indian Ridge,the Pb isotopes during the cycle processes of hydrothermal fluid trend to homogeneous;the monomineral Cu isotopic compositions of sulfide are positive with the range of (0.02-0.52)×10-3 ,so that the characteristics of hydrothermal sulfide from Southwest Indian Ridge are heavy Cu-rich appreciably;He,Pb and Cu isotope of hydrothermal sulfide from Southwest Indian Ridge record the characteristics of hydrothermal vent fluid and source of metal, and mineralization sources of Hydrothermal Sulfide are MORB and seawater with significant recycling and late reformation of hydrothermal fluid.