植被覆盖区遥感矿化蚀变异常信息提取与找矿预测——以诸广山地区铀矿为例  

Remote Sensing Extraction of Alteration Anomaly Information and Uranium Prospects Prediction in Vegetation Areas:A Case Study of Uranium Exploration in Zhuguangshan District

作　　者：徐光春 孙岳 伍敏婷[1,2] 韦祥蓬 刘鹏飞 方培岳 XU Guangchun;SUN Yue;WU Minting;WEI Xiangpeng;LIU Pengfei;FANG Peiyue(National Key Laboratory Uranium Resource Exploration-Mining and Nuclear Remote Sensing,Nanchang,Jiangxi 330013,China;School of Earth Sciences,East China University of Technology,Nanchang,Jiangxi 330013,China;Zhejiang Zhezhong Geological Engineering Survey Institute Co.,Ltd.,Jinhua,Zhejiang 321000,China)

机构地区：[1]铀资源探采与核遥感全国重点实验室,江西南昌330013 [2]东华理工大学地球科学学院,江西南昌330013 [3]浙江省浙中地质工程勘查院有限公司,浙江金华321000

出　　处：《铀矿地质》2024年第5期951-963,共13页Uranium Geology

基　　金：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基金(编号:6142A01210405);国家自然科学基金(编号:42162013)联合资助。

摘　　要：诸广山地区位于南岭成矿带中段,是我国重要的铀矿集区和产铀基地。大面积植被覆盖制约了遥感找矿技术在该区铀矿找矿工作中的进一步应用。文章基于Landsat8 OLI和Sentinel-2A MSI数据,使用归一化植被指数掩膜高植被覆盖区、植被抑制法对低植被覆盖区进行抑制,并结合支持向量机的分类方法掩膜人工建筑群等其他干扰因素,形成一套针对植被覆盖区的掩膜与抑制方法。依据与研究区铀矿化密切相关的白云母、水云母、绿泥石等含羟基矿物和赤铁矿、褐铁矿等含铁离子的矿化蚀变矿物的反射波谱特征,选取特定波段进行比值并与主成分分析法组合,提取羟基矿化蚀变和铁染矿化蚀变异常信息。通过系统分析所得的蚀变异常信息及断裂缓冲区中的重合区,结合区域地质背景,圈定了2处铀矿找矿有利区。野外验证表明,已发现铀矿床(点)与矿化蚀变异常信息吻合度较高,找矿有利区地表赤铁矿、褐铁矿、水云母化等矿化蚀变发育明显,具有进一步铀矿找矿价值。Located in the central segment of the Nanling metallogenic belt,Zhuanguangshan region is a significant uranium mineralization cluster and production base in China.However,the vegetation is a challenge to the application of remote sensing technology.Based on Landsat8 OLI and Sentinel-2A MSI data,this study applied a normalized difference vegetation index mask to identify areas with high vegetation coverage.Low vegetation coverage areas were suppressed by selecting the red and near-infrared bands.Additionally,a support vector machine classification method was employed to mask other interference factors,such as artificial building groups,to form a set of masks and suppression methods for vegetation coverage district.The study also leveraged the reflectance spectral characteristics of metamorphic minerals closely linked to uranium mineralization in the study area,including muscovite,phlogopite,chlorite,hematite,and goethite.Specific wavelength ratios were selected,combined with PCI(Principal Component Analysis)to extract hydroxyl and iron-oxides alteration anomaly information.This method led to the delineation of two new exploration targets.Field validation indicated a high degree of consistency between the discovered uranium deposits and the altered anomaly information.The favorable prospecting areas also exhibit significant developed alteration minerals such as limonite,hematite,and hydroxyl mica,and is believed potential for further uranium exploration.

关 键 词：铀矿 植被覆盖区 矿化蚀变异常信息提取 Landsat8和Sentinel-2A 诸广山 

分 类 号：P627[天文地球—地质矿产勘探]