西藏努日铜多金属矿南矿段地质特征及短波红外光谱的勘查应用  

Geological Characteristics of the South Section of the Nuri Copper Polymetallic Deposit in Tibet and the Exploration Application of Short-Wave Infrared Spectra

作　　者：汤立伟 王艺云[2] 陈文庆 陈斌[3] 吴志山[1] 缪恒毅 吴波 陈龙照 TANG Liwei;WANG Yiyun;CHEN Wenqing;CHEN Bin;WU Zhishan;MIAO Hengyi;WU Bo;CHEN Longzhao(The Second Geological Exploration Institute of CMGB,Fuzhou,Fujian 351111;Chengdu Center of China Geological Survey,Chengdu,Sichuan 610081;No.2 Bureau of China Metallurgical Geology Bureau,Fuzhou,Fujian 350100)

机构地区：[1]中国冶金地质总局第二地质勘查院,福建福州350108 [2]中国地质调查局成都地质调查中心,四川成都610081 [3]中国冶金地质总局二局,福建福州350100

出　　处：《地质与勘探》2024年第5期932-943,共12页Geology and Exploration

基　　金：国家重点研发计划项目(编号:2021YFC2901903和2023YFC2906805);中国冶金地质总局地质综合研究项目(编号:[2022]CMGBDZYJ005);中国地调调查局地质调查项目(编号:DD20240069)联合资助

摘　　要：西藏努日斑岩-矽卡岩型矿床作为冈底斯成矿带上发现的唯一具有Cu-W-Mo矿化组合的大型矿床,带上找矿潜力较大,成果丰硕。随着区带成矿理论和矿区研究程度的深入,亟需使用新的方法和技术手段来满足区内深部找矿的需要。本次研究利用短波红外光谱技术SWIR(Short wave infrared),对努日铜多金属矿床南矿段中典型蚀变矿物进行研究,根据其矿床地质特征、蚀变矿物组合、分带特征以及光谱分析结果,总结了矿区典型蚀变矿物短波红外光谱特征值分布规律,进而确定其勘查标志。研究认为白云母的吸收峰位值Pos2200>2208 nm、伊利石的吸收峰位值Pos2200>2203 nm、绿泥石的吸收峰位值Pos2250>2249 nm的大量或连续出现,可以作为努日矿区矽卡岩型铜多金属矿床有效的蚀变矿物勘查指标;在此基础上,综合努日南矿段地质特征分析、蚀变矿物分布规律分析,对矿区深部斑岩型铜矿进行成矿预测,认为南矿段45线东侧深部的石英闪长(玢)岩具有斑岩型铜矿找矿的潜力,为矿区下一步的找矿提供了方向与思路。The Nuri deposit in Tibet is the only large deposit with Cu-W-Mo mineralization in the Gangdese metallogenic belt,with great prospecting potential and fruitful results.With the deepening of mineralization theory and research,there is an urgent need to use new methods and technologies to meet the needs of deep mineral exploration in the region.This study used short wave infrared spectroscopy(SWIR)to study typical altered minerals in the southern section of the Nuri copper polymetallic deposit.Based on the geological characteristics of the deposit,altered mineral combinations,alteration mineral zoning characteristics,and spectral analysis results,this work summarized the distribution patterns of SWIR spectral characteristics of typical altered minerals,and then determined the exploration indicators.The study concludes that indicators including albite Pos2200>2208 nm,illite Pos2200>2203 nm,chlorite Pos2250>2249 nm,can be used as effective exploration indexes of alteration minerals for the Nuri skarntype Cu-polymetallic deposit.Accordingly,this study conducted metallogenic prediction of the deep porphyry copper deposit based on the geological characteristics and the distribution patterns of altered minerals in the southern Nuri ore district.It is inferred that the quartz diorite(porphyrite)on the east side of the prospecting line No.45 in the southern ore section has the potential for prospecting porphyry copper deposits,which provides direction and ideas for the future prospecting in the mine.

关 键 词：短波红外光谱 蚀变矿物 铜多金属 努日南矿段 冈底斯成矿带 

分 类 号：P618.41[天文地球—矿床学] P618.65[天文地球—地质学]