黑龙江三合屯金矿床早白垩世成矿作用及找矿意义OA
Early Cretaceous Mineralization and Prospecting Significance of the Sanhetun Gold Deposit in Heilongjiang Province:Evidence from Geochemistry and Isotopic Geochronology of Diorite-Prophyrite
黑龙江三合屯金矿位于中生代滨太平洋成矿域,地处多宝山NE-SW向早白垩世金成矿带南部.该矿区已探明金资源量4.4 t,金最高品位达23.70 g/t,伴生银最高品位135.82 g/t,具有较好找矿潜力.然而,该矿床成矿时代与找矿标志不清,制约了区域深边部勘查突破.为厘定该矿床的成矿时代、揭示矿床成因并构建找矿标志,本文开展了系统的野外地质调查、岩矿心编录、岩石地球化学及Rb-Sr同位素测年分析.结果表明:(1)闪长玢岩与金矿体空间展布一致,成矿期石英脉-黄铁矿与金矿化关系密切;(2)Rb-Sr同位素测年获得成矿年龄为115.7±9.1 Ma,闪长玢岩年龄为120±2 Ma,二者同属早白垩世,成矿略晚于岩浆活动;(3)闪长玢岩属亚碱性系列,富集大离子亲石元素(Ba、K、Sr),亏损高场强元素(Nb、Ta、Zr、Th)及重稀土元素,锆石εHf(t)值为4.7～7.6;(4)石英脉-黄铁矿组合的⁸⁷Sr/⁸⁶Sr比值为0.70654～0.71089,指示成矿物质主要源自幔源.综合区域成矿背景,认为三合屯金矿形成于早白垩世伸展构造背景,是与闪长玢岩有关的热液型金矿床,并明确提出闪长玢岩可作为多宝山地区早白垩世热液型金矿的重要找矿标志.该研究为区域金矿勘查部署提供了年代学与地球化学依据.
Abstrace:The Sanhetun gold deposit is located in the southern part of the Duobaoshan NE-SW-trending Early Cretaceous gold metallogenic belt within the Mesozoic Circum-Pacific Metallogenic Domain.It contains proven gold resources of 4.4 t,with a highest gold grade of 23.70 g/t and the highest associated silver grade of 135.82 g/t,indicative of significant exploration potential.However,the unclear metallogenic age and prospecting criteria of this deposit have constrained further exploration breakthroughs in the deep and marginal areas of the region.To determine the metallogenic age,the genesis and prospecting criteria of the deposit,this study conducted systematic field geological surveys,drill core logging,petrogeochemical analysis,and Rb-Sr isotopic dating.Results show that:(1)The diorite porphyrite is spatially consistent with the gold ore bodies,and the metallogenic-stage quartz-pyrite veins are closely related to gold mineralization.(2)Rb-Sr isotopic dating yields a metallogenic age of 115.7±9.1 Ma and a diorite porphyrite age of 120±2 Ma,both belonging to the Early Cretaceous,with mineralization occurring slightly later than magmatic activity.(3)The diorite porphyrite belongs to the sub-alkaline series,enriched in large ion lithophile elements(Ba,K,Sr)and depleted in high field strength elements(Nb,Ta,Zr,Th)and heavy rare earth elements,with zircon εHf(t)values ranging from 4.7 to 7.6.(4)The ⁸⁷Sr/⁸⁶Sr ratios of the quartz-pyrite assemblage range from 0.70654 to 0.71089,indicating that the ore-forming materials were mainly derived from a mantle source.Based on the regional metallogenic background,the Sanhetun gold deposit was formed in an Early Cretaceous extensional tectonic setting,which is a hydrothermal gold deposit related to diorite porphyrite.The diorite porphyrite is proposed as an important prospecting criterion for Early Cretaceous hydrothermal gold deposits in the Duobaoshan area.This study provides chronological and geochemical evidence for the deployment of regional gold exploration.
杨元江;李成禄;李旭东;谷华娟;刘宝山;侯占德;李博文
黑龙江省自然资源调查院,黑龙江 哈尔滨 150036黑龙江省自然资源调查院,黑龙江 哈尔滨 150036中国地质调查局牡丹江自然资源综合调查中心,黑龙江 牡丹江 157021黑龙江省自然资源调查院,黑龙江 哈尔滨 150036中国地质调查局沈阳地质调查中心,辽宁 沈阳 110034中国地质调查局哈尔滨自然资源综合调查中心,黑龙江 哈尔滨 150086黑龙江省自然资源调查院,黑龙江 哈尔滨 150036
天文与地球科学
闪长玢岩地球化学Rb-Sr等时线年龄白垩世三合屯金矿多宝山地区黑龙江
diorite-porphyritegeochemistryRb-Sr isochron ageCretaceousSanhetun gold depositDuobaoshan areaHeilongjiang Province
《地质与勘探》 2026 (2)
322-341,20
黑龙江省自然科学基金项目(编号:LH2023D025)、黑龙江省地质矿产局科研项目(编号:HKY202301)和中国地质调查局东北地质科技创新中心区创基金项目(编号:QCJJ2023-11)联合资助.
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