- 责任者：Zhu Feilin (State Key Laboratory of Ore Deposit Geochemistry ; Institute of Geochemistry ; Chinese Academy of Sciences ; Guiyang 550002 ; China) ; Tao Yan
- 刊名：Acta Petrologica Sinica
- 出版年：2011
- 卷期：27(9)
- 关键词：镍矿 ; nickel ores ; 铜矿 ; copper ores ; 铂矿 ; platinum ores ; 铼—锇计时 ; Re-Os dating ; 四川 ; Sichuan Province
- 页码：p.2655-2664
- 图表：4 illus., 2 tables, 54 refs.
- 分类号：1001
- 出版序号：576
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
The Qingkuangshan Ni-Cu-PGE deposit, located in the Xiaoguanhe area of Huili County, Sichuan Province, is one of the typical Ni-Cu-PGE deposits in the Emeishan Large Igneous Province(ELIP).In this paper, the Re and Os concentrations and Os isotopic compositions of the sulfide ores and associated ultramafic rocks in the Qingkuangshan deposit are studied in detail. The analyses indicate that the sulfide ores and associated ultramafic rocks can be divided into three types on the base of their Os compositions. Olivine websterites have low γOs values from 15.3 to 40.3. Massive sulfide ores and disseminated sulfide ores have similar γOs values that range up to about 260. Net-structured sulfide ores have the highest γOs values up to about 1000.The study shows that the Qingkuangshan Ni-Cu-PGE deposit is formed by multi-stage magma evolution, and that the primary magma was picritic. By model analyzing, the ore-forming mechanism can be concluded as follows: 1) primary magma has undergone lower crustal contamination in a deep magma chamber in the lower crust, and that the segregation of a small quantity of sulfide led to the formation of moderately PGE depleted magma; 2) sulfides in the net-structured sulfide ores originated from a second stage of contamination and sulfide segregation at an R≈1000 in the lower crust from the moderately PGE depleted magma; 3) the moderately PGE depleted magma underwent the further contamination and further sulfide segregation(R≈5000) in the upper crust.