摘要
研究区位于中祁连地块南缘,青海湖南-古雷深大断裂南侧,是祁连成矿带铜镍矿找矿最有利地区。铜镍矿矿体产于同源同期侵入的基性-超基性岩体内,铜镍矿化无论在时间上和空间上都与岩体的侵位密切相关。本次研究对乙什春基性-超基性岩体中的锆石进行了阴极发光(CL)成像观察,结合Th/U比值特征,显示其为岩浆成因;并应用LA-ICP-MS对锆石微区U-Pb年龄进行了测定,获得乙什春含矿岩体中锆石加权平均年龄为(455.1±1.7)Ma,表明其含矿岩体的侵位及矿化作用发生于晚奥陶世,成岩成矿的动力学背景为陆缘裂谷构造环境。
The study area is located at the southern margin of the Middle Qilian,south of the Qinghai Lake-GuLei deep fault belt,which is a favorable area for copper-nickel deposits in Qilian metallogenic belt.Yishichun Copper-nickel ore occurs within the homologous and contemporaneous basic-ultrabasic intrusions,and copper-nickel mineralization is spatially and temporally related to the intrusive rocks.The cathodoluminescence（CL） images and the Th/U ratios of zircons from the basic-ultramafic rocks suggest that zircon crystals are of magmatic origin;The LA-ICP-MS U-Pb dating of these zircons yields a weighted mean age of 455.1±1.7 Ma.Therefore,the ore-bearing rock emplacement and copper-nickel mineralization occurred during the late Ordovician,and the metallogenic dynamic process was probably related to an ancient continental margin rifting.
出处
《高校地质学报》
CAS
CSCD
北大核心
2012年第1期158-163,共6页
Geological Journal of China Universities
基金
青藏专项"北祁连成矿带成矿条件研究与找矿靶区优选"(1212010818090)
中国地质调查局大调查项目"北山-祁连成矿带地质矿产综合研究"(1212010010405)
