基于ASTER与Sentinel-2A融合数据的云南普朗铜矿化蚀变信息提取

Extraction of Mineralization Alteration Information from ASTER and Sentinel-2A Remote Sensing Fusion Data in the Pulang Copper Mine of Yunnan Province

云南普朗铜矿区是我国提高战略性金属矿产铜矿资源的主要潜力地段,该矿区位于多云多雨山地高原区,采用传统地面调查方法开展找矿勘查工作受限较大,而遥感技术可在其中发挥重要作用。鉴于此,本研究选取ASTER和Sentinel-2A多光谱遥感数据,在光谱协同统一两种数据源的地表反射率基础上,采用高通滤波(High-Pass Filtering,HPF)的融合方法兼顾两种数据在短波红外波段和可见光近红外波段的优势,获取了具有高空间分辨率和高光谱保真度的ASTER-Sentinel-2A融合数据集;进而利用“比值+主成分分析法”与“主成分分析+能谱-面积法”,开展了普朗铜矿区矿化遥感蚀变信息识别,并通过深入分析及野外验证,提出了对普朗铜矿蚀变信息分布特征及找矿潜力地带的新认识:(1)在原蚀变填图工作中判定为青磐岩化带的东部区域,重新进行了蚀变带的划分;(2)东部区域中新划分的钾化硅化带和绢英岩化带,具有较大找矿潜力。本研究可为普朗铜矿找矿勘查提供参考。

The Pulang copper mine of Yunnan Province is a major potential area of the strategic metal mineral copper resources in China.It is located in a mountainous and plateau area with often cloudy and rainy weather.The traditional ground survey method is limited in prospecting in this district,and remote sensing technology can play an important role in this operation.In this work,ASTER and sentinel-2A data,which are freely available and complementary,are used to unify surface reflectances through spectrum collaboration.Then,ASTER-Sentinel-2A fusion data with high spatial resolution and high spectral resolution are obtained by the high-pass filtering(HPF)fusion method.The optimized“Ratio+PCA”and“PCA+S-A”are used to extract mineralization alteration information from remote sensing data.Through in-depth analysis and field verification,a new understanding to the Pulang porphyry copper mine is proposed as follows.(1)The alteration zone should be redivided in the eastern area which has been determined to be a propylitic zone in original alteration mapping.And(2)it is speculated that the newly divided potassium-silicified and sericitization belts in the eastern region have great prospecting potential.This study can provide a scientific basis for further prospecting in the Pulang copper mine.