地质通报2017，Vol.36Issue(12)：2143-2153,11.
安第斯与冈底斯成矿带斑岩铜矿床矿物学和成矿斑岩地球化学特征对比
Comparison of geological mineralogy and geochemical characteristics be?tween ore-bearing porphyries of porphyry deposits in the Andean and the Gandise metallogenic belts
摘要
Abstract
In this paper, the authors analyzed and compared the geochemical characteristics of the magmatites related to porphyry cop?per deposits between the Andean and Gangdise metallogenic belts based on the summarizing of the geological mineralogical differenc?es of both the ore-bearing porphyries and the mineralization mechanisms between the porphyry copper ores formed in two different tectonic backgrounds. The porphyry copper deposits in the Andean metallogenic belt were developed during the subduction process of oceanic crust, and they were mainly formed in the late Eocene-Oligocene (43～31Ma) and the middle Miocene- Pliocene (12～4Ma). Their metal combinations include Cu-Mo and Cu-Au. The components of SiO2 in the ore-baring porphyries vary in a large range, and the lithologies of these porphyries change from intermediate to acidic, dominated by the series of calcium alkaline-high potassium calcium alkaline rocks. Only a small part of the ore-bearing porphyries has typical adakite geochemical characteristics, whereas most of ore-bearing porphyries in the Andean metallogenic belt have the volcanic rock geochemical characteristics of nor?mal arc series. The porphyry copper deposits in the Gangdise metallogenic belt were mainly developed during the continental colli?sion process, and they were mainly formed in the Miocene (20～12Ma). Their metal combination is Cu-Mo with the lack of the com?bination of Cu-Au. The lithologies of ore-bearing poryphries are mainly acid, the poryphyries are dominated by magmatic rocks with high potassium calcium alkali, and the ore-bearing porphyries have typical adakite geochemical characteristics. The ore-bearing porphyries in the Andean metallogenic belt might have been formed during the partial melting process of the wedge mantle material metasomatized by the fluid which was released from the crust plate and the MASH procedure. They were not developed directly from the partial melted oceanic crust. The ore-bearing porphyries in the Gangdise metallogenic belt might have been formed during the partial melting process of the subduction accretion arc with the change of deep tectonic dynamic mechanism, which was caused by the multi-subduction of ocean crust and was shortened and thickened during the continental collision process.关键词
安第斯/冈底斯/斑岩铜矿床/成矿斑岩/地球化学特征Key words
Andes/Gangdise/porphyry copper deposit/ore-bearing porphyry/geochemical characteristics分类
天文与地球科学引用本文复制引用
朱小三,卢民杰,程文景,宋玉财,张超..安第斯与冈底斯成矿带斑岩铜矿床矿物学和成矿斑岩地球化学特征对比[J].地质通报,2017,36(12):2143-2153,11.基金项目
国家自然科学基金项目《基于深反射地震资料探讨扬子古陆块和华夏古陆块元古代碰撞造山带》(批准号:41404070)、中国地质调查局项目《安第斯成矿带区域地球物理特征与优势矿产资源潜力分析》(编号:DD20160102-2)、《内蒙古东南部三维建模区地球物理数据采集与解释》(编号:DD20160125-03)和《海上丝绸之路大洋洲和南美洲矿产资源潜力评价》(编号:DD210160110) （批准号:41404070）
