黑龙江省东宁县金厂金矿石英和闪锌矿激光^(40)Ar-^(39)Ar法年龄及其找矿意义  

Automatic Laser Probe ^(40)Ar/^(39)Ar Isochron Ages of the Quatrz and Sphalerite from the Jinchang Gold Deposit,Dongning County,Heilongjiang Province, and their Prospecting Implications

作　　者：卿敏[1] 唐明国[1] 肖力[1] 赵玉锁[1] 韩先菊[1] 

机构地区：[1]武警黄金地质研究所,河北廊坊065000

出　　处：《地质与勘探》2012年第5期991-999,共9页Geology and Exploration

基　　金：全国危机矿山典型矿床及成矿规律总结研究项目"晋东北-内蒙古中部地区火山岩型金多金属矿床成矿规律总结研究(项目编号20089925)资助

摘　　要：黑龙江省东宁县金厂金矿是滨太平洋成矿域浅成低温-斑岩成矿系统中极具代表性的特大型金矿床。矿区已发现爆破角砾岩筒型、环状-放射状裂隙充填型、似层状微细脉浸染型和断控构造破碎带蚀变岩型等矿化类型。为确定成矿时间,作者应用高精度单颗粒激光熔蚀氩氩法,选择Ⅻ号破碎带蚀变岩型矿体中多金属硫化物-石英脉中石英和J-9号爆破角砾岩筒型矿体中闪锌矿进行年龄测定。获得Ⅻ号矿体石英40Ar/39Ar等时线年龄为119±5Ma(MSWD=6.3),J-9号矿体闪锌矿40Ar/39Ar等时线年龄为129±0.8Ma(MSWD=3.7),限定了成矿作用的上限。结合最新获得的相关成矿地质体精细年代学成果,进一步认定金厂金矿成矿时代为燕山晚期,成矿与同时代闪长玢岩-花岗闪长斑岩关系密切。金厂金矿成岩、成矿环境具备寻找富金斑岩型铜矿的有利条件,与成矿关系密切侵入岩呈岩脉、岩枝状,指示矿区剥蚀程度浅,深部还有发现斑岩型Au(Cu)矿化的可能。The Jinchang gold deposit in Dongning County of Heilongjiang Province is a typical super-large gold deposit in the epithermal-porphyry mineralization system of the Pacific marginal metallogenic mega-province. The mineralized rock bodies can be classified into four types：breccia type,ring -radial fault-controled vein type, layered-like micro-vein and disseminated type, and fractured alteration type. To determine the metallogenic age, we measured the age of the quartz of polymetallic sulfide-quartz in No. XH fracture altered ore body, and the sphalerite in No. J-9 explosive breccia pipe ore body by the high-precision single-grain Ar-Ar laser probe method. The results show that the 40Ar/39Ar isochron age for the quartz from the No. XH ore body is （119±5 ） Ma （MSWD = 6.3 ） , and the 40 At/a9 Ar isoehron age of the sphalerite from the No. J-9 ore body is （129±0.8） Ma （MSWD = 3.7 ）. Combining with the latest available detailed chronology of the related geological bodies, we confirm that the metallogenie age of the Jinchang gold deoposit is in the late Yanshanian, and its mineralization has a close relationship with the contemporary diorite-granodiorite porphyries. The diagenetic and metallo- genic environment of the Jinchang gold deposit provides a favorable condition to search for gold-rich porphyry type copper deposits, where the intrusive rocks associated with mineralization exhibit the shape of dikes and branches, indicative of a low erosion degree, implying a great possibility to discover deep -seated porphyry type Au（Cu） mineralization.

关 键 词：激光40Ar-39Ar年龄 石英 闪锌矿 找矿 金厂金矿 黑龙江省东宁县 

分 类 号：P618[天文地球—矿床学]