Study on distribution characteristics of underground space alteration information of drill core using hyperspectral technology

Alteration information is an important prospecting element in the exploration of deep earth resources. Hyperspectral technology has unique advantages in fine detection and inversion of altered mineral information. Drill core spectral scanning based on hyperspectral technology can identify mineral information in cores nondestructively, rapidly and in batches, which provides an effective means for revealing deep alteration information and its distribution characteristics. In this paper, we use this technology to study the alteration types and combination characteristics of the underground space of the typical deposit in the Kalatag ore collection area, as well as the distribution characteristics of the three-dimensional space of alteration information, and obtain the alteration mineral types and their relative content cataloguing curves of the 10,000 meter drilled cores in different exploration lines. The drill core in the mining area can be divided into three main alteration zones from the shallow part to the deep part, combined with the analysis of the geological core catalogue data. The upper zone is dominated by iron oxide, gypsum and aluminum-sericite. The middle zone is mainly composed of medium aluminum sericite, chlorite, and montmorillonite, with a small amount of high aluminum sericite and iron oxide compounds. In the lower zone, the altered minerals are dominated by high-alumina sericite and chlorite, with a small amount of medium-aluminum sericite and carbonate, as well as sericite and chlorite show obvious negative correlation. There are significantly different types of altered minerals, mineral assemblage characteristics and alteration scale in each alteration zone and between the zones, which reflects that the mineral generation environment has obvious differences with the change of drilling depth. Comprehensive research based on the differences of mineral formation environments can provide important support for deep exploration of underground alteration spatial characteristics, redox zoning, inversion of hydrothermal fluid characteristics and comprehensive analysis of metallogenic environments.