摘要
武夷山成矿带是中国东部中生代火山岩区重要的金铜多金属成矿带之一。为进一步对武夷山成矿带的岩矿蚀变信息进行识别与对比研究,该文利用机载航空高光谱SASI短波红外数据和星载高分五号(GF-5)高光谱数据,在充分分析不同蚀变矿物的实测波谱典型吸收特征和矿化蚀变信息识别提取方法的基础上,基于迪开石、高岭石、石膏、铁绿泥石、铁镁绿泥石、镁绿泥石等6种蚀变矿物的实测光谱特征,应用光谱角填图法(Spectral Angle Mapper,SAM)对闽中永泰—德化—尤溪矿集区的两类高光谱影像的蚀变矿物信息进行自动匹配识别和信息提取。研究表明:①两类高光谱数据都能较好地提取出上述6种典型蚀变矿物的分布范围,且结合地质资料能够推测出火山机构,暗示了较好的找矿前景;②通过对提取的蚀变矿物信息的效果和特征进行对比研究,并经野外实测岩矿样品的光谱验证,SASI数据提取的蚀变矿物信息与实际验证点吻合更多;③通过对比分析,发现应用高空间分辨率SASI数据的蚀变矿物信息提取结果较空间分辨率较低的GF-5数据更加稠密和精确,与空间分辨率越低,像素光谱混合越明显、地物精细区分程度也相对较差的常规认识相吻合。由于该研究中光谱验证点相对较少,且矿物种类有限,同时原始空间分辨率不同等因素,评价结果还需作进一步验证。
Wuyishan metallogenic belt is one of the important gold-copper polymetallic metallogenic belts in Mesozoic volcanic rock area in eastern China.To further identify and compare the alteration information of rocks and minerals in the Wuyishan metallogenic belt,with the airborne hyperspectral SASI short-wave infrared data and the space-borne Gaofen No.5(GF-5)hyperspectral data,based on the analysis of the typical absorption characteristics of the measured spectra for different altered minerals and the recognition and extraction methods of mineralized alteration information,as well the measured spectral characteristics of six altered minerals,namely,dickite,kaolinite,gypsum,chlorite_Fe,chlorite_FeMg,chlorite_Mg,the authors applied Spectral Angle Mapper(SAM)to automatic matched,identify and extract the altered mineral information of hyperspectral images in Yongtai-Dehua-Youxi ore concentration area of central Fujian.The research shows that:①Combined with geological data,the two kinds of hyperspectral data can well define the distribution range of the above six typically altered minerals and infer the volcanic structure,suggesting a good prospecting prospect;②The comparative study on effect and characteristics of the extracted altered mineral information and the spectral verification of samples in the field indicate the altered mineral information extracted from the SASI data is more consistent with the actual verification point;③Through the comparative analysis,it is found that the extraction results of altered mineral information using high spatial resolution SASI data is denser and more accurate than the GF-5 data with low spatial resolution,which is consistent with the conventional understanding that the lower spatial resolution,the more obvious pixel spectral mixing,and the poorer the fine distinction of ground objects.Due to the relatively few spectral verification points,the limited mineral species,and the different original spatial resolution in this study,the evaluation results need to be further verified.
作者
倪斌
黄照强
郭健
邢光福
张亚龙
牛斯达
NI Bin;HUANG Zhaoqiang;GUO Jian;XING Guangfu;ZHANG Yalong;NIU Sida(Institute of Mineral Resources Research,China Metallurgical Geology Bureau,Beijing 101300,China;Nanjing Center,China Geological Survey,Nanjing,210016,Jiangsu,China)
出处
《华东地质》
2023年第1期67-81,共15页
East China Geology
基金
国家重点研发计划“武夷德化-尤溪-永泰矿集区矿物地球化学勘查研究(编号:2016YFC0600210)”
中国冶金地质总局科技创新项目“高光谱遥感资源生态环境评价方法与技术研究(编号:CMGB202001)”
中国冶金地质总局矿产资源研究院科技创新“武夷地区高光谱生态地质环境研究”和“基于CASI/SASI航空高光谱数据的生态环境地物特征提取方法研究”项目联合资助
