地质学报2017，Vol.91Issue(12)：2727-2738,12.
四川西部里伍式富铜矿床黄铜矿Re-Os定年及其成矿意义
Re-Os Isotopic Dating of Chalcopyrite from the Liwu-Type Copper Deposit in Western Sichuan and its Metallogenic Significance
摘要
Abstract
The Liwu-type copper deposit refers to stratiform or stratiform-like or lenticular Cu-rich ore deposits occurring in the suture zone between the western margin of the Yangtze block and Songpan-Ganzi fold belt.Research of geological features,mineralization type and mineralography indicates that the Liwu-type copper deposit belongs to hydrothermal deposits.In order to accurately constrain the metallogenic age,we performed NTIMS Re-Os geochronological dating for the chalcopyrite from massive-veined ores.The results show isochron ages of chalcopyrites ranging from 150.2 ± 4.9 to 151.1 ± 4.8 Ma (2σ),indicating that the Liwu-type copper deposit formed in the Late Jurassic,distinctly later than the sedimentary time of the wall rock (Liwu Group),but roughly close to the age of the granite outcropping at the edge of Jianglang dome.Initial 187Os/188Os value of chalcopyrites is 3.65±0.29,suggesting that the ore-forming materials came mainly from the continental crust,probably from the Liwu Group.Combined with the tectonic-magmatic events of the dome,this paper proposed that the magmatic thermal uplifting caused by the early Yanshanian extension in the Songpan-Ganzi fold belt not only provided thermal forces and partial fluids for Cu mineralization,but also led to the formation of ore-inducing and orecontaining structure space.Therefore,magmatic thermal uplifting was the key factor of the formation of Liwu-type copper deposits.关键词
NTIMS Re-Os定年/黄铜矿/里伍铜矿/江浪穹窿/四川西部Key words
NTIMS Re-Os dating/chalcopyrite/Liwu-type copper deposit/Jianglang dome/Western Sichuan引用本文复制引用
李同柱,周清,张惠华,代堰锫,李超,沈战武,马东..四川西部里伍式富铜矿床黄铜矿Re-Os定年及其成矿意义[J].地质学报,2017,91(12):2727-2738,12.基金项目
本文为国家自然科学基金青年基金(41202067)、中国地质调查局矿产资源评价项目(1212011085139)、成都地质调查中心青年科学基金项目(所控基[2015]-05)资助的成果. （41202067）
