青海省祁连县清水沟—白柳沟矿田含矿火山岩系年代学研究  

Chronological Study of Meta-Acidic Volcanics in Qingshuigou-Bailiugou Orefield,Qilian County of Qinghai Province

作　　者：余吉远[1] 李向民[1] 马中平[1] 孙吉明[1] 王建强[1] 

机构地区：[1]中国地质调查局西安地质矿产研究所,陕西西安710054

出　　处：《地球科学进展》2010年第1期55-60,共6页Advances in Earth Science

基　　金：青藏专项研究计划项目"北祁成矿带成矿条件研究与找矿靶区优选"(编号:1212010818090);中国地质调查局大调查项目"中亚古生代火山岩形成机制及其与成矿关系研究"(编号:1212010611804);国家"305"项目"阿尔金山大型镁铁质层状杂岩体铜镍铂矿资源潜力调查及找矿靶区优选"(编号006DAB07B03-021)资助

摘　　要：研究区位于北祁连山西段,区内出露有南北2个火山穹窿,分别为南侧的清水沟—香子沟火山穹窿和北侧的大柳沟—白柳沟火山穹窿;北侧穹窿中已发现的矿床均产出于穹窿周边,而南侧穹窿中目前发现的矿床产出于穹窿的中心,研究认为矿床与火山穹窿关系十分密切。矿田中铜多金属矿床均产出于酸性火山岩中,LA-ICP-MS单颗粒锆石U-Pb测年,获得含矿酸性火山岩成岩年龄为(502.6±3.1)Ma,表明清水沟—白柳沟矿田成岩成矿时代为中寒武世,含矿火山岩系形成环境为大陆裂谷环境,是新元古代Rodinia超大陆裂解作用的产物。The study area is located in the North Qilian Mountains, where two volcanic domes are exposed： The Qingshuigou-Xiangzigou volcanic dome on the southern side and the Daliugou-Bailiugou volcanic dome on the northern; the deposits found all occur in the periphery of the northern volcanic dome, while the deposits occur in the center of southern volcanic dome. The studies suggest that the relationship between deposits and volcanic domes are very close. The copper-polymetallic deposits all occured in acidic volcanic rocks. By LA-ICP-MS zircon U-Pb dating, we obtained （502.6± 3.1 ） Ma as the age of the ore-bearing acidic volcanic rocks is indicating the age about rocks and ores of the Qingshuigou-Bailiugou orefield which formed in the Middle Cambrian. The formation environment of these ore-bearing volcanic rocks is the continental rift environment, and these ore-bearing volcanic rocks are the products of the Rodinia supcrcontinent rifting in Neoproterozoic.

关 键 词：铜多金属矿床 LA—ICP-MS定年 清水沟-白柳沟矿田 北祁连山 

分 类 号：P597.3[天文地球—地球化学]