Discovery of Bismuth Mineral of the Garqiong Copper-Gold Ore Deposits in Tibet and Its Significance
详细信息
- 责任者：Xiao Yuanfu (Chengdu University of Technology ; Chengdu 610059 ; China) ; Wang Qiang
- 刊名：Acta Geologica Sinica
- 出版年：2012
- 卷期：86(7)
- 关键词：铜矿 ; copper ores ; 金矿 ; gold ores ; 铋矿 ; bismuth ores ; 西藏 ; Tibet
- 页码：p.1106-1112
- 图表：illus., 2 tables, 23 refs.
- 分类号：1001
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Bangong Lake-Nujiang River metallogenic belt is an important copper-polymetal ore belt in Tibet. It extends about 2000 km from east to west, bounded by the Lhasa block to the south and the Qiangtang block to the north. With investigation deepening, it was found that bismuthic mineralization is distributed in the shape of belt. Garqiong is one of the places which hosts the key skarn-type copper-gold deposit in the metallogenic belt. Based on field geological investigation and sampling, and microscope and SEM analysis, an independent bismuth-bismuthinite mineral was identified, and it is an important Bi-bearing mineral ever found in the Bangong Lake-Nujiang River metallogenic belt. In addition, Osmium-bearing native bismuth, emplectite, tetradymite, sulfur-containing tetradymite unnamed BiTe2 and other natural elements minerals of the bismuth, telluride and sulfate mineral were also found. The research results have enriched the variety of bismuth minerals and have great importance in deposit research and in determining the direction of future prospecting. Based on microscope identification and fluid inclusion temperature, paragenetic relation between Cu-Au and Bi, migration of Bi in ore-forming fluid as sulfur complex, and formation of bismuthinite in the high T hydrothermal fluid were all discussed in this study. U-Pb dating of zircon from the ore-bearing rocks is 83. 2-87. 1 Ma using LA-ICP-MS, and the Re-Os model ages of molybdenite are between 86. 87-87. 29 Ma in the Garqiong copper-gold ore deposits. The deposit should belong to skarn-type copper-gold ore deposits resulted from magmatic hydrothermal contact metasomatism in origin.