摘要
合龙钨矿床位于南岭东西向构造岩浆带与北-北东向于山构造带交汇部位,是南岭东段于都-赣县矿集区的重要组成。合龙钨矿床是赣南地区近年在石英脉型钨矿勘查取得最重要突破的矿区,新发现钨多金属矿体达48条,新探明黑钨矿资源量3.5万余吨,WO_3平均品位2.189%,深部具有大型以上资源潜力。合龙钨矿床以外带石英大脉型矿体与岩体内石英细脉-云英岩型钨矿体分带共生为特色,区别于经典的石英脉型钨矿床的"五层楼"分带,也不同于"西华山式"仅岩体内成矿和"盘古山式"的仅岩体外成矿,故对其开展成岩成矿时差研究、内外带成矿过程对比研究和成矿模式研究具有重要意义。本文在矿床地质工作基础之上,对该矿床进行了较详细的矿物学研究,对比了不同阶段、不同分带黑钨矿和白钨矿的矿物化学特征;应用LA-ICP-MS锆石U-Pb法获得深部隐伏中细粒斑状黑云母花岗岩的成岩年龄为159.0Ma;应用辉钼矿Re-Os等时线法,测定了内带石英脉-云英岩型矿体成矿时代为157.3Ma,外带石英脉型矿体成矿时代为159.6Ma。研究表明,合龙钨矿床形成于燕山早期,是华南东部中生代大规模花岗质岩浆活动与钨多金属成矿作用的产物,其成矿作用紧随花岗质岩浆侵入而发生,成岩与成矿时间基本一致。内脉带矿化略晚于外脉带钨矿化,外脉带黑钨矿以相对高温阶段形成的含锰钨铁矿为主,内脉带黑钨矿则以成矿作用中晚期的含铁钨锰矿为主。基于上述研究成果,本文建立了"合龙式"钨矿床成矿模式,对石英脉-云英岩型钨矿成矿理论研究具有一定的推动作用,对下一步勘查工作部署具有重要实践意义。
The Helong W deposit is an important component of the Yudu-Ganxian ore cluster in southern Jiangxi Province,which is located at the intersection of the N-NE-trending and the E-W-trending tectonic-magma belt in the eastern Nanling region.It has made notable discovery in the deep exploration of quartz vein-greisen type W ore-bodies recently.Up to now,48 W-dominant ore bodies have been newly discovered and reserve more than 35,000 tons WO3 with an average grade of 2.189%.The Helong deposit is characterized by the coexistence of quartz vein type W ore-bodies in exocontact zone and quartz vein-greisen type W ore-bodies in endocontact zone,controlling by the concealed granitic intrusion.It is different from the classic"five floors"zoning of quartz vein type W deposit,and advanced to the"Xihuashan-type"and the"Pangushan-type"which are only mineralized at the endocontact or extrocontact zone.In this paper,based on the detailed work of deposit geology,the metallogenic stages and mineral formation sequence are established,and the mineralogical characteristics of wolframite and scheelite in different zonal ore-bodies are compared.Using LA-ICP-MS zircon U-Pb method,we obtained the rock-forming age of the medium-fine grained biotite granite is 159.0 Ma.Using the Re-Os isochron method of molybdenite,we obtained the ore-forming age of quartz vein-greisen type W ore-bodies in endocontact zone is 157.3 Ma,while that of quartz vein type ore-bodies in exocontact zone is 159.6 Ma.This study shows that the Helong W deposit was formed in the Early Yanshanian,resulting from the large-scale granitic magmatism and W polymetallic mineralization of South China in Mesozoic,and the W mineralization just followed the intrusion of granitic magma.The quartz vein-greisen type mineralization in the endocontact zone is slightly later than the quartz vein type W mineralization in the exocontact zone.The wolframite in the exocontact zone is mainly Mnbearing wolframite formed in the relatively high temperature stage,while the wolframite in the endocontact zone is mainly Fe-bearing wolframite formed in the relatively late mineralization stage.Based on these studies,this paper establishes the"Helong type"W metallogenic model,which is beneficial to the theoretical research of quartz vein-greisen type W deposit,and has important practical significance for the future exploration in the Nanling region.
作者
尹政
赵正
陶建利
吴胜华
李宏伟
甘加伟
陈伟
李小伟
YIN Zheng;ZHAO Zheng;TAO JianLi;WU ShengHua;LI HongWei;GAN JiaWei;CHEN Wei;LI XiaoWei(School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China;MNR Key Laboratory of Metallogeny and Mineral Asessment,Instiute of Mineral Resources,Chinese Academy of Geological Sciences,Beiying 100037,China;South Jjiangxi Geological Surney Party,Jjiangxi Bureans of Geology and Mineral Resource Exploration and Derelopment,Ganzhou 341000,China)
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第5期1531-1552,共22页
Acta Petrologica Sinica
基金
国家重点研发计划项目(2016YFC0600208)
国家自然科学基金项目(41973046)
中国地质调查局项目(JYYWF20180502)联合资助。
关键词
合龙钨矿
石英脉型
云英岩型
成矿时代
成矿模式
Helong W deposit
Quartz vein type
Greisen type
Geochronology
Metallogenic model
