Sulfur and Lead Isotope Compositions of the Hutouya Copper-Lead-Zinc Polymetallic Deposit in Qinghai Province and Their Genetic Significance

详细信息   

• 责任者：Ma Shengchao (Key Labaratory of MetaUogeny and Mineral Resource Assessment ; MLR ; Institute of Mineral Resources ; CAGS ; Beijing 100037 ; China) ; Feng Chengyou
• 刊名：Geology and Prospecting
• 出版年：2012
• 卷期：48(2)
• 关键词：铅锌矿床 ; lead-zinc deposit ; 多金属矿 ; polymetallic ores ; 青海 ; Qinghai Province
• 页码：p.321-331
• 图表：6 illus., 24 tables, 2 refs.
• 分类号：1001
• issnNo：ISSN0495-5331
• isbnNo：CN11-2043/P

摘要

The Hutouya Pb-Zn polymetallic ore district in Qinghai Province is a typical one in the Qimantage metallogenic belt of East Kunlun in Qinghai Province. This paper studies the characteristics of sulfur and lead isotopes from the Hutouya ore district, and analyses the source of ore-forming materials. The 834S values of sulfide minerals such as chalcopyrite, galena, sphalerite, and pyrite sulfides range from ＋0.6 ‰ to ＋ 8.3‰, with an average value of 4.4%0. The narrower distribution range and the lower average of the 834 S value indicate the source of sulphur is mix of crust sulfate with deep -source magma sulphur. The 834S peak values are different, which may be associated with the difference in host-rock sulphur. The main δ34S values ran- ging from ＋2.2‰ to ＋7.4‰ and the narrow distribution range imply the homogenization happened in high-temperature deep sources or when the sulphur was transported up to the upper crust. The variation range of lead isotopic ratios is also smaller. The 206Pb/204Pb, 207 Pb/204 Pb and 208 Pb/204 Pb ratios of sulfide ores are 18. 476 -18. 688, 15.56 - 15. 688 and 38. 261 - 38. 599, respectively. This may indicate that the lead isotope of sulfides is from the same deep magma source area. Lead isotope ratios of the mining area is mainly distributed within the scope defined by the evolution lines of the orogenic belt and upper crust, implying that the lead isotope originated from mixture of upper crust and mantle. As the result of the different wall rock and dominant ore-control factors, lead isotopes from different ore belts of sulfides exhibit certain differences. For example, compared with the ²⁰⁷ Pb/²⁰⁴Pb ratio of the Chulutaohai copper polymetallie mine nearby the VI ore belt within the Tanjianshan group with the II ore belt in the contact zone between the rock mass and the Diaosu group, the lead isotope of the later one may contain more lead from the upper crust, which further proves the influence of crusl-mantle mixing on the Hutouya ore district.