Application of the three-component transient electromagnetic method in gold exploration: a case study of the Heicigou gold deposit in east Kunlun

Heicigou gold mine is a gold polymetallic mine controlled by a northwest trending fault. The magnetic method and induced polarization results show that the gold-bearing alteration zone is distributed discontinuously in a northwest direction, but the spatial distribution characteristics of the alteration zone have not been effectively identified. Although some drilling work has been carried out in the latter, the number and the depths of the drillings have been insufficient to control the distribution of the alteration zone. According to the measured three-component transient electromagnetic anomaly characteristics, we designed corresponding models and carried out three-component forward simulation on the platform of EMIT Maxwell. We summarized the corresponding relationship between the three-component plane change characteristics and the orientation and occurrence of the low-resistivity medium subsurface. We applied this method to the Heicigou gold deposit and found that the occurrence of the ore-bearing alteration zone is northeast. This discovery solved the problem that the previous magnetic method and induced polarization method failed to solve. It corrected the geologists' incorrect understanding of the spatial distribution of the alteration zone.