黑龙江多宝山斑岩铜矿床叠加改造地质特征及成因  

Genesis and Geological Characteristics of Superposition and Deformation of the Duobaoshan Porphyry Cu(Mo)Deposit,Heilongjiang

作　　者：刘宝山[1] 张春鹏[1] 宋万兵 韩仁萍[1] LIU Baoshan;ZHANG Chunpeng;SONG Wanbing;HAN Renping(Shenyang Center of Geological Survey,China Geological Survey,Shenyang 110034,Liaoning,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034

出　　处：《大地构造与成矿学》2020年第6期1076-1095,共20页Geotectonica et Metallogenia

基　　金：国家“十三五”重点研发计划深地项目(2017YFC0601305);中国地调局项目(DD20190156)联合资助

摘　　要：多宝山斑岩铜矿床位于早古生代多宝山岛弧带上,地处兴安地块东缘,是东北地区正在开采的最大的超大型铜矿床。本文通过对含矿斑岩韧性变形构造序次的分析,发现矿石矿物的赋存状态除早期的星点状、细脉浸染状斑岩型矿化外,还叠加有后期沿片理面和糜棱面理分布的脉状、透镜状矿化。NW向韧性剪切变形造成原斑岩中的铜矿化发生迁移与再定位,使变形带中的铜矿化局部富集。在详细的矿区调查和同位素年代学研究的基础上,发现研究区存在五期岩浆侵入和三期成矿作用,其中早奥陶世花岗闪长岩(~478 Ma)及中奥陶世花岗闪长斑岩(~460 Ma)为主成矿期,晚三叠世更长花岗岩(225.8±0.4 Ma)产生弱铜钼矿化,中侏罗世安山玢岩(170±5.6 Ma)及早白垩世闪长岩(118.1±6.6 Ma)没有产生铜钼矿化。多宝山斑岩铜矿床受古亚洲洋及蒙古‒鄂霍茨克洋两大构造域叠加控制,经历了多期构造‒岩浆和成矿事件,发生了叠加改造。The Duobaoshan porphyry copper deposit is the largest porphyry copper deposit in production in NE China.Previous researches demonstrated that it was formed in the early Paleozoic Duobaoshan island arc belt located in the eastern segment of the Xing’an block.Through a ductile deformation sequence analyses of the ore-bearing porphyry,we found that the early stage star-like and vein-disseminated ores were superimposed by the lateral vein-like and lenticular mineralization along schistosomiasis and mylonite foliation.The NW ductile shear deformation led to the migration and relocation of the early stage copper ores,and local enrichment in ductile structural deformation zone.On the basis of field geological survey and geochronological research,five magmatic stages and three metallogenic epochs are identified,including the main metallogenic period of the early Ordovician granodiorite(ca.478 Ma)and middle Ordovician granodiorite porphyry(ca.460 Ma),the weakly mineralized stage of the late Triassic granite(225.8±0.4 Ma),and the none affected mineralization stage of the middle Jurassic andesite porphyry(170±5.6 Ma)and the early Cretaceous diorite(118.1±6 Ma).The Duobaoshan porphyry copper deposit is influenced both by the Paleo-Asian and Mongolia-Okhotsk domains,and underwent multistage tectonic-magmatic activities and metallogenic events.

关 键 词：多宝山岛弧带 多宝山斑岩铜钼矿床 叠加改造矿床 片理化 糜棱岩化 

分 类 号：P611[天文地球—矿床学]