摘要
洋灰洞子斑岩型矿床位于黑龙江省牡丹江市、兴蒙造山带东缘,其成矿岩体为花岗闪长斑岩,利用LA-MC-ICP-MS法获得成矿斑岩锆石U-Pb年龄为(191.6±1.7)Ma,为早侏罗世。地球化学特征指示该斑岩具有高铝低镁的特征,为钙碱性系列、(强)过铝质岩石,样品相对富集大离子亲石元素(Rb、Ba、K),相对亏损高场强元素(Nb、Ta、P、Ti)。岩体源区为下地壳,形成于蒙古—鄂霍次克洋壳俯冲环境,俯冲导致富集地幔底侵于陆壳底部形成初始岩浆,沿软弱面和裂隙上涌,演化为花岗闪长斑岩。兴蒙造山带晚三叠世至早侏罗世岩浆侵入活动导致一期重要的铜、钼矿床成矿事件,本区岩体深部及周边晚三叠至早侏罗世岩体的含矿性值得作进一步评价。
Yanghuidongzi Cu deposit of porphyry type is located in the eastern margin of the Xingmeng orogenic belt in Mudanjiang City of Heilongjiang Province,and its ore-forming rock body is granodiorite porphyry.The LA-MC-ICP-MS method is used to obtain the zircon U-Pb dating age of(191.6±1.7)Ma for the ore-forming porphyry,which is Early Jurassic.Geochemical feature indicates that the porphyry is characterized by high aluminum and low magnesium,which belongs to the calcium-alkaline series and(strong)peraluminous rock.The samples are relatively enriched with large ion philophile elements(Rb,Ba,K),and are relatively deficient in high field strength elements(Nb,Ta,P,Ti).The source area of rock mass is the lower crust,which is formed in the Mongolian-Okhotsk oceanic crust subduction environment.The subduction causes the enriched mantle bottom to invade the bottom of the continental crust to form an initial magma,upwelling along the weak surface and fissures,and is evolved into granodiorite porphyry.The Late Triassic to Early Jurassic magmatic intrusion in the Xingmeng orogenic belt leads to an important metallogenic event of copper and molybdenum deposits.The ore-bearing properties of the deep rock mass in this area and Triassic to Early Jurassic rock mass in the surrounding areas should be made further evaluation.
作者
曾冠中
赵玉锁
许佳琪
赵由之
闫家盼
张翔
ZENG Guanzhong;ZHAO Yusuo;XU Jiaqi;ZHAO Youzhi;YAN Jiapan;ZHANG Xiang(Institute of Gold Geology of CAPF,Langfang 065000,Hebei,China;China Nonferrous Metal Mining(Group)Co.,Ltd.,Beijing 100011)
出处
《矿产与地质》
2020年第5期923-934,961,共13页
Mineral Resources and Geology
基金
武警黄金部队黄金专项项目(编号:201504040003)资助。
