摘要
晚古生代,新疆西北缘地处古亚洲洋中部,是我国中亚造山带的重要组成部分,伴随着晚古生代强烈的构造岩浆活动,发生了明显的金铜成矿作用,形成了300多个金铜矿床和矿点,已经成为我国重要的金铜矿产开发基地之一。新疆西北缘金铜成矿作用主要有4种类型,即 VMS 型、韧性剪切带型、火山热液型和斑岩型,所形成的矿床具有成群分布、分段集中的特点,构成了阿尔泰铜多金属成矿带、额尔齐斯金矿带、萨吾尔金铜成矿带、哈图金矿带、包古图金铜成矿带等。新疆西北缘金铜成矿作用与该地区晚古生代洋-陆转化过程中的俯冲、碰撞和后碰撞演化密切相关。早泥盆世,阿尔泰南缘的斋桑洋向北俯冲,形成克兰弧后盆地,伴随双峰式火山活动和热液活动,形成阿舍勒等 VMS 型块状硫化物矿床;中泥盆世-早石炭世,斋桑洋向南俯冲,在西准地区北缘形成萨吾尔岛弧,并伴随着钙碱性火山活动和阔尔真阔腊等火山热液型金矿床的形成,与此同时,准噶尔洋向北俯冲,在西准地区东南部形成哈图弧后盆地和包古图岛弧,发生拉斑系列火山活动和哈图火山热液型金矿床的形成以及随后的中酸性岩浆侵入和包古图富金斑岩型铜矿床的形成;晚石炭纪—二叠纪发生弧陆碰撞及后碰撞的伸展,形成多拉纳萨依等韧性剪切带型金矿床。金铜成矿作用在新疆西北缘贯穿于整个晚古生代,在晚古生代早期形成的金铜矿床可能遭受了晚期弧陆碰撞和(或)后碰撞的构造岩浆活动的叠加和改造,显示了新疆西北缘金铜成矿作用的多期性和复杂性。
Upper Paleozoic gold and copper mineralization in the northwestern Xinjiang is of great economic interest. About 300 gold and copper deposits and spots have been discovered in northwestern Xinjiang. According to their host rocks and geneses, these gold and copper mineralizations can be classified into four major types： （1） volcanic-hydrothermal massive sulfides （VMS） type; （2） ductile-shear-zone type; （3） volcanogenic hydrothermal type; （4） porphyry type. They form several important metallogenic belts that include the Altay polymetallic metallogenic belt, Irtysh gold metallogenic belt, Sawur gold-copper metallogenic belt, Hatu gold metallogenic belt and Baogutu gold-copper metallogenic belt. Tectonically, the gold and copper mineralization was closely associated with the subduction, collision and postcollision of the Paleoasian Ocean intervened between the Siberian block and the Junggar block. An important bimodal volcanic epoch was occurred in the back-arc basin during the Early Devonian in the southern margin of the Siberian block, during which the Ashele deposit formed. In the Middle Devomian-Early Carboniferous, S-dipping subduction of Zaisan Ocean led to formation of the Sawur arc, which triggered calc-alkaline volcanic activity, leading to formation of the volcanogene hydrothermal gold deposits. In the meantime, N-dipping subduction of Junggar Ocean led to formation of the Baogutu arc and Hatu back-arc basin, which triggered tholeiite volcanic activity and the emplacement of granitic and dioritic porphyries, leading to formation of the volcanogene hydrothermal gold deposits and porphyry Cu-Au deposits. In the Late Carboniferous to Early Permian, during the closure of the ancient ocean, land-arc collisional and extensional events in the southern margin of the Ahay result in the formation of ductile-shear-zone gold deposits. The gold and copper mineralization occurred in the northwestern Xinjiang could run through the whole Late Paleozoic, which the gold and copper deposits formed in ear
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第5期1087-1100,共14页
Acta Petrologica Sinica
基金
中国科学院知识创新工程(编号KZCX2-YW-107)
国家305项目(编号2006BAB07B01)联合资助成果
关键词
金铜成矿作用
构造环境
新疆西北缘
Gold and copper mineralization
Tectonic setting
Northwestern Xinjiang
