新疆白杨河铀矿床钻孔岩芯蚀变分带特征及地质意义  

Alteration zonation of drilling cores in the Baiyanghe uranium deposit of Xinjiang and its geological implications

作　　者：侯腱膨 徐清俊 叶发旺[3] 张川[2,3] 孟树[3] HOU Jianpeng;XU Qingjun;YE Fawang;ZHANG Chuan;MENG Shu(School of Geoscience and Technology,China University of Petroleum(East China),Qingdao 266580,Shandong,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;National Key Laboratory of Science and Technology on Remote Sensing Information and Image Analysis,Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]核工业北京地质研究院遥感信息与图像分析技术国家级重点实验室,北京100029

出　　处：《中国地质》2018年第4期839-850,共12页Geology in China

基　　金：核工业地质局项目"铀及多金属矿产勘查高光谱遥感综合应用示范研究"(YLTY1604)资助~~

摘　　要：钻孔岩芯高光谱技术是获取岩芯地学信息与研究的新方向。新疆白杨河铀矿床钻孔岩芯蚀变发育,对其开展蚀变研究有助于对白杨河矿床深部铀矿勘探提出更好的找矿认识。本次研究利用Field Spec4可见光-短波红外地面非成像光谱仪对新疆白杨河铀矿床8个钻孔进行光谱测试与分析,研究发现钻孔岩芯热液蚀变矿物组合垂向上具有明显的"上低下高中过渡"的三分带特征:即上部为低铝绢云母+少量赤铁矿与少量褐铁矿+少量蒙脱石,中部为中铝绢云母+低铝绢云母+少量蒙脱石+少量碳酸盐、赤铁矿与褐铁矿,下部为高铝绢云母+绿泥石+碳酸盐;绢云母Al-OH吸收峰位置变化规律反映出矿床的热液活动具有深部相对高温、高压、偏酸性,浅部相对低温、低压、偏碱性的特征。蚀变三分带特征以及热液活动特征表明白杨河铀矿床具有明显的热液成矿背景,同时,铀矿化总体处于3分带特征中的中部以中铝绢云母为主的蚀变带与下部以高铝绢云母为主的蚀变带之间的过渡带中,该过渡带是铀成矿的有利部位,同时也是可能的热液/矿化中心;过渡带中发育赤铁矿,中铝绢云母和高铝绢云母,此3种蚀变矿物可能与铀成矿关系密切。这些可以为白杨河铀矿床深部铀矿勘探提供借鉴与参考。Hyperspectral technology of drilling cores,which can provide geological information of drilling core,is a new research direction.Alteration of drilling cores is developed in the Baiyanghe uranium deposit,and the study of alteration can provide better reference for deep uranium exploration.In this paper,the spectra of eight drilling cores in the Baiyanghe deposit were measured and analyzed by FieldSpec4 visible-shortwave ground-based infrared spectrometer,and the results show that the hydrothermal alteration mineral assemblage of the drilling cores has three types of obvious zonation features,which is named“the upper is high,the bottom is low and the middle is transitional”,In detail,Al-poor muscovite+a little hematite,limonite and montmorillonite assemblage is in the upper part of the drilling core,intermediate Al-content muscovite+Al-poor muscovite+a little hematite,limonite,montmorillonite and carbonate assemblage is in the middle,Al-rich muscovite+chlorite and carbonate assemblage is at the bottom.The varieties of muscovites Al-OH absorption peak reflect the hydrothermal activities of the deposit,whose feature is that the relatively higher temperature,higher pressure and more acidic hydrothermal fluid is in the depth,and things are just the opposite in the upper part.The characteristics of three types of zonation and hydrothermal activities show that the Baiyanghe uranium deposit probably has obvious hydrothermal ore-forming background and uranium mineralization is located in the transition zone,which may be a favorable site for uranium mineralization and possible hydrothermal/mineralization centers.The transition zone develops hematite,intermediate Al-content muscovite,and Al-rich muscovite,which may be closely related to uranium mineralization.These data can provide reference and information for the deeper exploration.

关 键 词：白杨河铀矿床 钻孔岩芯 热液蚀变矿物 绢云母 Al-OH吸收峰 

分 类 号：P627[天文地球—地质矿产勘探]