摘要
福建霞浦大湾钼铍矿床产于火山岩区,但成矿作用可能与岩浆活动和裂隙构造关系密切。为查清矿区隐伏的钠长石化碱长花岗岩与钼铍矿成矿作用之间的关系,本文运用激光剥蚀电感耦合等离子体质谱法(LA-ICP-MS)对碱长花岗岩进行锆石U-Pb测年研究,获得年龄结果为93. 0±0. 6 Ma,与矿区的辉钼矿成矿年龄(92. 2±1. 3 Ma)一致,表明碱长花岗岩与钼铍矿成矿作用时空上具有密切的成因联系,岩浆活动可能为矿区钼铍矿的形成提供了成矿物质和成矿流体。结合区域上的成岩成矿年代学数据,本研究认为福建省燕山期岩浆活动时代与钼铍矿成矿时代都具有从西向东逐渐变新的时空分布规律,钼铍矿的成矿地质构造背景为燕山期华南岩石圈伸展环境。
BACKGROUND:The Mo-Be deposit in Xiapu Dawan,Fujian Province is located in a volcanic rock area.Mineralization may be closely related to magmatic activity and fracture structure.The concealed granite in the deposit is considered to be the parent rock of Mo-Be ore,but there is no direct time evidence.OBJECTIVES:To determine the relationship between albite alkali-feldspar granite and Mo-Be mineralization in this deposit by the geochronology of alkali-feldspar granite.METHODS:LA-ICP-MS was used for zircon U-Pb dating of alkali-feldspar granite.RESULTS:The results show that the U-Pb age of alkali-feldspar granite is 93.0±0.6 Ma,consistent with that of molybdenum mineralization in this deposit(92.2±1.3 Ma),which indicates that the alkali-feldspar granite is closely related to the mineralization of Mo and Be in time and space.Magmatic activity may provide ore-forming materials and fluids for the Mo-Be ore deposits.CONCLUSIONS:The Upper Yanshanian magmatic age and the Mo mineralization age in Fujian Province have the temporal and spatial distribution regularity that becomes gradually younger from west to east.The Mo-Be deposit occurred in the extension of the South China lithosphere during the Yanshanian period.
作者
黄新鹏
HUANG Xin-peng(Institute of Geological Survey of Fujian Province,Fuzhou 350013,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2018年第5期572-579,共8页
Rock and Mineral Analysis
基金
中国地质调查局地质调查工作项目"华南重点矿集区稀有稀散和稀土矿产调查"(DD20160056)
关键词
大湾钼铍矿
碱长花岗岩
成岩时代
时空联系
地质背景
Dawan Mo-Be deposit
alkali feldspar granite
diagenetic age
space-time connection
geological background
