地质与勘探2018，Vol.54Issue(1)：9-19,11.
北祁连塞浦路斯型硫化物成矿构造环境研究─与现代劳海盆对比
A Study on the Tectonic Setting of Cyprus-Type Sulfide Deposits in the North Qilian Mountains:Comparison with the Modern Lau Basin
摘要
Abstract
The"Cyprus-type"sulfide deposits in the North Qilian mountains formed in the upper part of Middle-Late Ordovician back-arc ophio-lites,which are characterized by a lot of pyroclastic and terrigenous clastic rocks. Their metallogenesis is related with volcanic activities,tensional faulting and tectonic movements there,and the hydrothermal circulation channels mainly consist of volcanical fractures,lava cooling cracks and so on,in keeping with the ore-forming locations. The regional faults are dominating channels of the high-temperature hydrotherm from deep usbsurface,and the source of mineralizer S in the east part is deeper than in the west,indicating a larger extending depth of faults. The metallogenesis can be divided into two stages, which are mainly controlled by volcanic activities and regional tectonic movements, corresponding to the"Cyprus-type"deposits in the east and west part, respectively. The spreading history of the mid-south Lau basin shows a pattern of cracking from north to south,while the dating data of North Qil-ian ophiolites implies a spreading history of cracking from west to east. Hydrothermal fields in the south of Lau basin(VFR) are still in a rifting setting, with some"Kuroko-type"deposits, which transit into"Cyprus-type"to the north. While the back-arc area of North Qilian is characterized by the"Cyprus type"deposits,where there are still many contemporaneous"Kuroko-type"deposits near the back-arc area in the east,manifesting the rifting in Ordovician. In addition,Ba/Nb and other trace element ratios indicate decreasing influence of subduction on the Lau basin from south to north. While the back-arc area of North Qilian is similar to modern Lau basin in this aspect,where the influence of subduction on the east part is more obvious than on the west,demonstrating that the earlier start of rifting could lead to less impact of subduction and vice versa. These lines of comparison are all similari-ties between Lau basin and the back-arc area of the North Qilian mountains.关键词
北祁连/劳海盆/塞浦路斯型硫化物矿床/海底热液Key words
North Qilian orogenic belt/Lau basin/"Cyprus-type"sulfide deposit/submarine hydrothermal fluid分类
天文与地球科学引用本文复制引用
范庆凯,李江海,刘仲兰,贠晓瑞..北祁连塞浦路斯型硫化物成矿构造环境研究─与现代劳海盆对比[J].地质与勘探,2018,54(1):9-19,11.基金项目
大型油气田及煤层开发国家科技重专项(编号:2016ZX05033002-007)和国家重点研发计划课题(编号:2016YFC0503301)联合资助. （编号:2016ZX05033002-007）
