钻孔岩心高光谱技术系统及其在矿产勘查中的应用

Drill Core Hyperspectral Technology System and Its Application in Mineral Prospecting

钻孔岩心高光谱技术是高光谱遥感技术的延伸运用方向,它将高光谱遥感矿物填图技术应用于深部钻孔岩心蚀变信息的提取,为深部地质研究提供了新的思路与方法。在遥感技术系统的基础之上建立了钻孔岩心高光谱技术系统体系,并以Hyspex钻孔岩心高光谱采集系统为例,对我国南方某火山岩型铀矿勘查区钻孔岩心高光谱数据进行了处理和示范性应用。岩心高光谱数据预处理包括辐射校正、反射率计算和光谱去噪3个步骤,之后的蚀变信息提取包括端元光谱识别和光谱匹配填图2个步骤。利用处理之后的岩心蚀变矿物全孔编录结果,进行了蚀变矿物空间分带规律分析和蚀变矿物组合划分,并对钻孔蚀变信息反映的深部流体环境进行了分析和反演,结合钻孔地质资料,发现该钻孔铀矿化富集部位处于蚀变矿物酸碱性发生突变的地球化学障部位这一特征。最后,对钻孔岩心高光谱技术的特点及优势进行了总结,其能够为深部矿产资源勘查提供有效技术支撑,值得进一步推广应用。

Drill core hyperspectral technology is the extension direction of hyperspectral remote sensing application. The application of hyperspectral remote sensing mineral mapping technology to drill core alteration information extraction provides a new method for deep geological research. In this paper, drill core hyperspectral technology system is established based on the remote sensing technology system. In the case of Hyspex acquisition system of drill core hyperspectral data, the hyperspectral data of drill core are processed and applied in an exploration area of volcanic rock type uranium deposits in southern China. The preprocessing of the drill core hyperspectral data consists of three steps including radiation correction, reflectivity calculation and spectra denoising, and then, alteration information extraction consists of two steps including endmember spectrum identification and mineral spectra matching mapping. Deep fluid environment is inversed by the analysis of altered minerals distribution features and mineral assemblage zonation based on the altered minerals logging chart of the whole bore in the uranium exploration area. The results show that uranium mineralization of the drill is located in the position of geochemical barrier with abrupt changes in acidity and basicity of altered minerals based on geological data of the drill. Finally, the paper summarizes the characteristics and the advantages of drill core hyperspectral technology and suggests that this method is useful for deep mineral resource exploration and valuable in geological application.