赣西七宝山钴铅锌矿床碧玉岩的发现及对矿床成因的制约  

The discovery of jasper rocks in the Qibaoshan cobalt-lead-zinc deposit in western Jiangxi Province and its restriction on the genesis of the deposit

作　　者：孙建东[1] 李海立[1] 张雪辉[1] 陆凡 徐敏成 卢致慧 SUN Jiandong;LI Haili;ZHANG Xuehui;LU Fan;XU Mincheng;LU Zhihui(Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China;265 Brigade of Jiangxi Province Nuclear Geology,Yingtan 335001,Jiangxi,China;Jiangxi Copper Group Co.Ltd.Qibaoshan Mining Co.Ltd.,Yichun 336400,Jiangxi,China)

机构地区：[1]中国地质调查局南京地质调查中心,江苏南京210016 [2]江西省核工业局265大队,江西鹰潭335001 [3]江西铜业集团有限公司七宝山矿业有限公司,江西宜春336400

出　　处：《地质通报》2023年第10期1718-1727,共10页Geological Bulletin of China

基　　金：国家重点研发项目《武夷德化-尤溪-永泰矿集区三维综合探测与深部成矿预测》(编号:2016YFC0600210);中国地质调查局项目《钦杭成矿带武宁-平江地区钨铜多金属矿地质调查》(编号:DD20190153);《江南陆块南缘成矿带(东段)战略性矿产调查》(编号:DD20240066)。

摘　　要：对赣西七宝山钴铅锌矿中的碧玉岩进行岩石学、地球化学研究,可为矿床成因及区域海底火山活动成矿作用提供地质证据。赣西七宝山钴铅锌矿床为中型钴矿床,主矿体产于石炭系黄龙组铁白云岩中,矿石结构以粒状、胶状结构为主,块状、层纹状硫化物矿体与新发现的碧玉岩空间相依,同地产出,密切相伴,互相包夹,表明其与成矿具有密切的共生关系,属同期沉积产物;碧玉岩主量、微量、稀土数据表明,其具有高硅贫铝富铁、锰特征,Al/(Al+Fe+Mn)值为0.13~0.16,与热水成因的硅质岩相当;富集Rb、Ba、U、La、Zr、Hf元素,亏损K、Nd、P、Ti元素,U/Th值为185.83~373.85,Y/Ho值为26.88~50.00,稀土元素总量低,为0.88×10^(-6)~2.16×10^(-6),LREE/HREE值介于0.07~0.36之间,轻、重稀土元素分馏程度不高,Ce无异常,δEu中等负异常,显示碧玉岩物质来源于深部海底热水,少量同生海水混合形成,形成于晚古生代陆缘裂谷海槽环境。研究成果为矿床属于海底火山喷流沉积成因提供了直接有利的证据。Qibaoshan Co-Pb-Zn deposit is a medium-sized cobalt ore deposit,the main ore body in carboniferous Huanglong Formation dolomite,ore structure is given priority to with granular,colloidal structure,block,layer striate sulfide ore bodies and newly discovered jasper rock spatial dependency,with output,close companions,sandwiched between each other,that with the mineralization has a close symbiosis,belong to the same period deposits;The main trace and rare earth data of the jasper rock show that it is characterized by high silicon,poor aluminum and rich in iron and manganese.The Al/(Al+Fe+Mn)ratio is 0.13~0.16,which is similar to the siliceous rocks of hydrothermal origin.Enrichment of Rb,Ba,U,La,Zr,Hf,depletion of K,Nd,P,Ti,U/Th ratio of 185.83~373.85,Y/Ho ratio of 26.88~50.00,ΣREE is low,ranging from 0.88×10^(-6)~2.16×10^(-6).The LREE/HREE values range from 0.07 to 0.36,and the fractionation degree of light and light rare earth is not high.The Ce anomaly is not found,and theδEu moderate negative anomaly indicates that the jade rocks material originated from deep seabed hot water,and a small amount of syngenetic seawater was mixed and formed in the Late Paleozoic continental margin rift trough environment.Therefore,it provides direct and favorable evidence that the deposit belongs to the sedimentary origin of submarine volcanic effluents.

关 键 词：七宝山 钴 碧玉岩 发现 矿床成因 矿产勘查工程 

分 类 号：P618.42[天文地球—矿床学] P618.43[天文地球—地质学] P618.62