摘要
砂岩型铀矿作为一种以表生流体作用为主的后生矿床,发育较多低温矿物。甘肃省彭阳铀矿是近年来新发现的一处深部砂岩型铀矿床,具有砂体规模大、铀矿化面积广、厚度大、等特点。在含矿层及周边发育方解石、石膏、黄铁矿、黏土矿物等低温成因矿物,研究矿物的空间分布特征及其与铀矿物的关系,对判别成矿流体的主要来源、性质以及对铀成矿的控制作用具有重要意义。近红外岩心光谱扫描技术可无损、快速、批量地识别出岩心中的层状硅酸盐矿物(如高岭石、蒙脱石、绢云母等),硫酸盐矿物(如石膏、明矾石等),碳酸盐矿物(如方解石、白云石等)等矿物信息,本文基于该技术对彭阳铀矿床的矿物类型及其组合进行研究。结果表明:洛河组发育高岭石、蒙脱石、伊利石(伊/蒙混层)、绿泥石、碳酸盐、石膏、铁氧化物等矿物,铀矿段的矿物组合为“伊利石(伊/蒙混层)+石膏+碳酸盐”,局部可见高岭石。根据矿物组合特征反演流体作用,洛河组含铀矿段矿在沉积期主要是一套碱性环境,成矿期存在还原性酸性流体的注入。
BACKGROUND:As an epigenetic deposit dominated by supergene fluid,a sandstone type uranium deposit has many low-temperature minerals.In recent years,the Pengyang uranium deposit,a deep sandstone type uranium deposit,has been discovered in the southwest edge of the Ordos Basin,China.The deposit has the characteristics of large sand body scale,wide uranium mineralization area,large thickness and high grade.Many low-temperature altered minerals have developed,including calcite,gypsum,pyrite,and clay minerals.It is of great significance to study the spatial distribution characteristics of minerals and their relationship with uranium minerals to identify the main sources and properties of ore-forming fluids and their controlling on uranium mineralization.Near-infrared core spectral scanning technology can identify layered silicate minerals such as kaolinite,montmorillonite,sericite,and sulfate minerals such as gypsum and alunite,and carbonate minerals such as calcite and dolomite.OBJECTIVES:To study the distribution characteristics of minerals and their relationship with uranium mineralization.METHODS:Core samples were scanned by VNIR-SWIR spectroscopy core scanning system and analyzed by TSG 8.0.In addition,the microscopic occurrence characteristics of minerals related to uranium minerals were observed by scanning electron microscopy.RESULTS:Minerals such as kaolinite,montmorillonite,illite,chlorite,carbonate,gypsum,and iron oxide were identified in the Luohe Formation.The mineral assemblage of uranium ore section was“illite+gypsum+carbonate”,and minor kaolinite was present locally.CONCLUSIONS:The uranium-bearing section of the Luohe Formation is mainly a set of alkaline environments in the sedimentary period.However,there is also an injection of reducing acid fluid in the metallogenic period.
作者
张博
司庆红
苗培森
赵华雷
朱强
陈印
陈路路
ZHANG Bo;SI Qinghong;Miao Peisen;ZHAO Hualei;ZHU Qiang;CHEN Yin;CHEN Lulu(Tianjin Center,China Geological Survey,Tianjin 300170,China;Key Laboratory of Uranium Geology,China Geological Survey,Tianjin 300170,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2022年第5期733-743,共11页
Rock and Mineral Analysis
基金
国家自然科学基金重点支持项目(92162212)
国家重点研发计划项目(2018YFC0604200)
中国地质调查局地质调查项目(DD20190472,DD20221678)
国际地球科学计划项目(IGCP675)。
关键词
砂岩型铀矿
彭阳铀矿床
近红外光谱扫描
反射光谱
扫描电镜
sandstone type uranium ore
Pengyang uranium deposit
near infrared spectrum scanning
reflection spectrum
scanning electron microscope
