胶东大尹格庄金矿床铅同位素地球化学  

Lead isotope geochemistry of Dayingezhuang gold deposit Jiaodong Peninsula China

作　　者：张良[1] 刘跃[1] 李瑞红[1] 黄涛[1] 张瑞忠[1,2] 陈炳翰 李金奎 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]招金矿业股份有限公司,招远265400 [3]中矿金业股份有限公司,招远265409

出　　处：《岩石学报》2014年第9期2468-2480,共13页Acta Petrologica Sinica

基　　金：国家自然科学基金重点项目(41230311);国家科技支撑计划课题(2011BAB04B09);地质过程与矿产资源国家重点实验室开放课题(GPMR201307)联合资助

摘　　要：胶东是我国最重要的金矿集区,破碎带蚀变岩型金矿床是其最重要的金矿床类型,该类型金矿床已探明金矿资源量占全区的90%以上,其巨量金的来源是引人瞩目的关键科学问题。招平断裂带是胶东金矿集区内规模最大的断裂-成矿带,其内已探明金资源量1500余吨,大尹格庄金矿床位于招平金矿带中段,是该金矿带最具代表性的破碎带蚀变岩型金矿床之一,目前勘探深度近-800m,已探明金金属量约125t。NNE向招平断裂带和NWW向大尹格庄断裂是区内主要控矿构造,其中招平断裂带沿胶东群与玲珑花岗岩接触带发育,控制了大尹格金矿床的产出。招平断裂带下盘为玲珑黑云母花岗岩,是金矿床的主要赋矿围岩,普遍发育黄铁绢英岩化蚀变;招平断裂带上盘为太古宇胶东群混合岩化黑云斜长变粒岩、碳酸盐片岩和斜长角闪岩及古元古代荆山群禄格庄组石榴矽线黑云片岩和黑云片岩,发育强烈的碳酸盐化。金矿化与绢云母化、黄铁矿化和硅化关系密切,金矿体赋存在招平断裂带下盘的黄铁绢英岩和黄铁绢英岩化花岗质碎裂岩中,主要金属矿物为黄铁矿,其次为方铅矿、闪锌矿和黄铜矿,且黄铁矿常与方铅矿和闪锌矿共生。以大尹格庄断裂为界,其南、北两侧分别为Ⅰ号和Ⅱ号矿体,它们是占大尹格庄金矿床探明储量的85%。相对于Ⅱ号矿体,Ⅰ号矿体具有更多的方铅矿和闪锌矿及更高的银含量。I号矿体9件矿石硫化物206Pb/204Pb、207Pb/204Pb和208Pb/204Pb分别为17.2638~17.3585、15.4663~15.6116和37.858~38.3328;II号矿体6件矿石硫化物206Pb/204Pb、207Pb/204Pb和208Pb/204Pb分别为17.2157~17.3286、15.4595~15.5084和37.8900~38.0004,为放射性成因的异常铅,经历了三阶段演化史。其中,3.4Ga左右壳幔分离,铅在地壳下部和上地幔得到充分混合,形成均一的正常铅;0.8Ga左右铅脱离第二阶段储库并与铀钍体系发生分离;其后,这种�The gold deposits of the Jiaodong Peninsula define the China＇ s largest gold province. Disseminated- and stockwork-style gold deposit, which accounts for 90% of the proved reserves in Jiaodong Peninsula, is the most important deposit type. Its giant source of gold is a striking and key scientific issue. Zhaoping fault zone, whose proved reserves exceed 1500t Au, is the largest fault- metallogenic belt in Jiaodong Peninsula. Dayingezhuang gold deposit, a typical disseminated- and stoekwork-style gold deposit, whose proved reserves are about 125t Au, located in the central part of Zhaoping metallogenic belt. Its exploration depth is nearly -800m. NNE-trending Zhaoping fault and NNW-trending Dayingezhuang fault are the main ore-controlling structures. The Zhaoping fault develops along the contacts between the Jiaodong Group and Linglong granite and controls the occurrence of the gold orebedies in Dayingezhuang gold deposit. Linglong granite locates in the footwaU of Zhaoping fault. Generally, it underwent pyrite-sericite-quartz alteration and hosts most part of the gold orebodies. Wall rocks in the hanging wall, which underwent intensive carbonation, comprise migmatization biotite-plagioclase-granulite, carbonate schist and amphibolite of Archaean Jiaodong Group, and gamet-sillimanite-biotite schist and biotite schist in the Lugezhuang Formation of Paleoproterozoic Jingshan Group. The gold mineralization is closely related to sericitization, pyritization and silication. The gold orebodies are located in the pyrite-sericite-quartz altered rock and pyrite-sericite- quartz altered cataclasite in footwall of Zhaoping fault. The main metallic mineral is pyrite, followed by galena, sphalerite and chalcopyrite. Frequently, pyrite is symbiotic with galena and sphalerite. The No. I and II orebodies, located in the south and north of the Dayingezhuang Fault respectively, account for 85% of the proved reserves in Dayingezhuang gold deposit. Comparing with the No. II orebody, the No. I orebedy possesses more galena, sphalerit

关 键 词：铅同位素 成矿物质来源 再活化 大尹格庄金矿床 胶东 

分 类 号：P597.2[天文地球—地球化学] P618.51[天文地球—地质学]