长江中下游成矿带(安徽段)斑岩型铜金矿床成矿作用特征  

Metallogenic characteristics of porphyry copper gold deposits in the middle and lower reaches of Yangtze River metallogenic belt(Anhui section)

作　　者：孙明明[1] 王利民[1] 赵先超[1] 高曙光[1] 陈静静 吴礼彬[1] SUN Mingming;WANG Limin;ZHAO Xianchao;GAO Shuguang;CHEN Jingjing;WU Libin(Geological Survey of Anhui Province〔Anhui Institute of Geological Sciences〕,Hefei 230001,Anhui,China)

机构地区：[1]安徽省地质调查院〔安徽省地质科学研究所〕,安徽合肥230001

出　　处：《矿产与地质》2021年第2期177-185,共9页Mineral Resources and Geology

基　　金：中国地质调查局中国矿产地质志项目“中国矿产地质志·安徽卷”(DD20190379-13)资助。

摘　　要：长江中下游成矿带(安徽段)以长江断裂带为界,存在江北和江南两条大致对称分布的斑岩带,是省内斑岩型铜金矿床的主要产区。从研究区斑岩型铜金矿床的构造环境、矿床地质特征、成岩成矿作用等方面入手,对两条斑岩带内的斑岩型铜金矿床进行了对比研究。研究表明:矿床位于下扬子被动陆缘(坳陷区)与宿松—肥东陆缘(隆起区)和江南隆起(隆起区)交汇部位,分布于NE向—NNE向区域性断裂构造旁侧,形成于燕山期陆内挤压到伸展的转换构造环境。成矿斑岩体属中酸性—中基性的(高钾)钙碱性系列,以复式斑岩体为主;岩性包括辉石闪长(玢)岩、石英闪长斑(玢)岩、英安玢岩、花岗闪长斑岩等,属石英闪长玢(斑)岩-花岗闪长斑岩-辉石闪长岩组合。矿体分布在斑岩体内部及其与碎屑岩或碳酸盐岩接触带部位,主要产于钾-硅质蚀变带和石英-绢云母化-黄铁矿化带内。成岩成矿作用与早白垩世玄武质岩浆底侵作用有关,成岩成矿物源相同,主要为幔源岩浆,有壳源物质混染。研究认为,江北斑岩带中的沙溪—新屯仓一带和江南斑岩带中的贵池—青阳—南陵一带仍具有较大的找矿潜力。The middle and lower Yangtze River metallogenic belt(Anhui section),bounded by the Yangtze River fault zone,has been divided into two roughly symmetrical porphyry belts of Jiangbei and Jiangnan,where are the main producing area of porphyry type copper-gold deposits in Jiangsu province.Based on the structural environment,geological characteristics and diagenetic mineralization of porphyry type copper-gold deposits in the study area,the author has carried out a comparative study on porphyry type copper-gold deposits in the two porphyry zones.It is indicated that the deposits are located at the intersection of the passive continental margin of lower Yangtze(depression area),the eastern continental margin of Susong-Feidong(uplift area)and the Jiangnan uplift(uplift area).Metallogenic porphyries belong to the series of medium acid and medium basic(high potassium)calc-alkaline,which are dominated by the complex porphyries.The lithology includes pyroxenite(porphyrite),quartz diorite(porphyrite),anglo-ian porphyrite,granite diorite porphyry,etc.,belonging to the combination of quartz diorite(porphyrite)-granite diorite porphyry-pyroxenite.The orebodies are distributed in the porphyry body and the contact zone with clastic rocks or carbonate rocks,and are mainly produced in the potassium-siliceous alteration zone and the quartz-sericite-pyrite zone.The diagenesis and mineralization are related to the early Cretaceous basaltic magma subduction,and the diagenetic mineral sources are the same,mainly the mantle-derived magma,with crust-derived materials mixed.It is considered that there is still a great prospecting potential in the Shaxi-Xintuncang area of Jiangbei porphyry belt and the Guichi-Qingyang-Nanling area of Jiangnan porphyry belt.

关 键 词：斑岩型铜金矿床 成矿作用 成矿特征 成矿规律 长江中下游成矿带 

分 类 号：P618.51[天文地球—矿床学] P618.41[天文地球—地质学]