基于GF-2和ASTER数据青海德龙地区构造蚀变信息提取及找矿预测

Tectonic alteration information extraction and prospecting prediction for the Delong area of Qinghai Province based on GF-2 and ASTER data

德龙地区位于青海东昆仑金及多金属成矿带东段,是该成矿带内极具勘查潜力区域之一,受限于偏远的地理位置和崎岖的地形条件,大比例尺地球化学勘查及常规地质调查工作难以直接开展。为此,基于ASTER和GF-2数据,通过分析不同空间分辨率遥感影像的色调、几何结构和纹理特征进行线性和环形构造识别;同时,根据主要蚀变矿物光谱特征分析,利用ASTER可见光—近红外波段和短波红外波段,采用“掩模+主成分分析”方法提取铁化、Al-OH和Mg-OH蚀变信息;在此基础上,结合多元地学信息及野外调查结果,综合分析遥感解译构造蚀变信息与研究区金矿化的内在联系,建立基于区内金矿床的遥感找矿预测模型,并以此为依据划分出找矿远景区3处。通过野外查证,在德龙找矿远景区新发现金矿体多条。研究结果表明,融合遥感数据和地理信息系统技术可有效识别地表热液蚀变和构造空间结构特征,能够为该地区进一步找矿预测提供参考和依据。

The Delong area,located in the eastern segment of the Eastern Kunlun gold-polymetallic metallogenic belt in Qinghai,is recognized as an area with significant exploration potential.However,its remote geographical location and rugged terrain pose challenges to large-scale geochemical explorations and conventional geological surveys.Based on ASTER and GF-2 data,this study identified the linear and circular structures by analyzing the color tones,geometric structures,and textures of remote sensing images with varying resolutions.Through the spectral analysis of primary alteration minerals,this study extracted the information on ferrugination,Al-OH,and Mg-OH alterations from visible light to near-infrared bands and short-wave infrared bands of ASTER using the mask+principal component analysis technique.Then,this study established a remote sensing-based prospecting prediction model for gold deposits in the study area by combining geoscience information and field survey results and comprehensively analyzing the association between the tectonic alteration information derived from remote sensing image interpretation and the gold mineralization of the study area.Using the prediction model,this study delineated three prospective areas for mineral exploration.The field verification revealed several new gold ore bodies in the Delong prospective area.The results show that the integration of remote sensing data and GIS technology can effectively identify surface hydrothermal alterations and tectonic spatial structures.The integration can serve as a guide for subsequent prospecting prediction of the study area.