Zircon LA-ICP-MS U-Pb Age of Monzogranites in the Kaerqueka Copper-Polymetallic Deposit of Qimantag, Western Qinghai Province

详细信息   

• 责任者：Chen Bo (Xi’an Center of China Geological Survey ; Xi’an 710054 ; China) ; Zhang Zhanyu
• 刊名：Geological Bulletin of China
• 出版年：2012
• 卷期：31(2)
• 关键词：铜矿 ; copper ores ; 多金属矿 ; polymetallic ores ; 铀—铅计时 ; U-Pb dating ; 青海 ; Qinghai Province
• 页码：p.463-468
• 图表：1 illus., 1 table, 8 refs.
• 分类号：1001
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

摘要

The Kaerqueka copper-polymetallic ore bodied in Qimantage region can mainly be found in monzonitic granite and skarn belts located in the contact zones between granodiorite,porphyritic biotitic monzogranite and Cambrian-Ordovician strata.Based on LA-ICP-MS U-Pb chronological study of zircons,the authors obtained the age（410.1Ma±2.6Ma） of biotitic monzogranite close to Ⅶ ore belt.Nevertheless,other researchers hold that the rock-forming and ore-forming processes took place in Indo-Chinese period based on the age of granodiorite（237Ma±2Ma） and the Re-Os model age（239Ma）of molybdenite.A comparison of the geochemical characteristics between the two rock bodies has led the authors to reach the conclusion that the mineralization was related not only to the Indo-Chinese intermediate-acid intrusive rocks but also to the late Caledonian acid intrusive rocks,and there existed a difference in magma origin between porphyritic biotitic monzogranite and granodiorite,suggesting that they were formed in different periods of tectonic evolution.Ore deposits in Qimantag region were formed in late Caledonian and in Indo-Chinese period.Although the outcrop of late Caledonian period is not so apparent as the one of Indo-Chinese period,due attention should be paid to the contribution of late Caledonian intrusives to mineralization.