巴音戈壁盆地本巴图地区高光谱矿物信息提取及铀矿勘查有利区筛选

Extraction of Mineral Information Using Hyperspectral Data and Prediction of Favorable Areas for Uranium Exploration in Benbatu Area,Bayingebi Basin

为了查明巴音戈壁盆地东部本巴图地区主要蚀变矿物类型和分布,以及与铀矿化之间的关系,为该地区下一步铀矿勘查提供新的技术方法支持。利用航空高光谱SASI和卫星GF-5号数据,采用光谱角填图(SAM)方法提取了高、中、低铝绢云母、高岭石、铁绿泥石、镁绿泥石、碳酸盐类、赤铁矿、褐铁矿等10余种矿物信息。含矿目的层巴音戈壁组上段提取的矿物信息主要为褐铁矿、赤铁矿和碳酸盐类,其次为中铝绢云母、铁绿泥石和石膏,与铀矿化关系密切的蚀变主要为褐铁矿化、赤铁矿化和碳酸盐化。新尼乌苏凹陷东北部下白垩统巴音戈壁组中提取的矿物信息具有一定的组合分带特征,从山往盆方向可划分出赤铁矿+褐铁矿+高岭石+中铝绢云母和褐铁矿+赤铁矿+碳酸盐类+铁绿泥石两种矿物组合分带,后者与铀矿化具有较好的空间对应关系,结合野外地质调查和已有地质、矿产、航放等资料,认为新尼乌苏凹陷东北缘是寻找砂岩型铀矿的有利地段。

In order to provide new technical support for the further uranium exploration in Benbatu area,eastern Bayingebi basin,airborne hyperspectral SASI and GF-5 satellite data was used to identify the main types and distribution of alteration minerals with Spectral Angle Mapping(SAM)method.More than ten types of minerals such as high,medium and low aluminum sericite,kaolinite,ferrite,magnesium chlorite,carbonate,hematite and limonite were extracted.The minerals extracted from the upper member of the Bayingebi formation mainly includes limonite,hematite and carbonate,followed by medium sericite,daphnite and gypsum.By analyzing their spatial relationship of extracted mineral and uranium mineralization,the alterations closely related to uranium mineralization was found to be ferritization,hematitization and carbonatization.The mineral assemblage in the Bayingebi formation of the Lower Cretaceous in the northeastern Xinniwusu sag was of some characteristic of zonation.Two types of mineral assemblages could be divided from the mountain to the basin,they are hematite-limonite-kaolinite-medium aluminum sericite and hematite-limonite-carbonateferrochlorite,respectively.The latter has a good spatial correspondence with uranium mineralization.Combined with the field geological survey and the available data of geology,mineral,and airborne gamma-ray spectrometry,the northeast of Xinniwusu sag was selected as a favourable area for sandstone type uranium deposit.