New development of the Electromagnetic (EM) methods for deep exploration

Abstract

Many studies have been carried out to demonstrate the huge potential of mineral resources greater than 500m. Therefore, it is of crucial importance to design an instrument locally for deep seated targets. Electromagnetic (EM) method is an important means for mineral exploration. With the development of airborne, surface and marine EM detection technology in China, Wire-less Electromagnetic Method ( WEM), Multi-channel Transient Electromagnetic Method (MTEM) , as well as Short-offset Transient Electromagnetic method (SOTEM) are focused on in this paper. The WEM wave propagates through lithosphere, atmosphere and ionosphere to probe 10 km-depth geo-electric structures underground; MTEM method is proven as an effective means for burying the target body; SOTEM reaches a depth of 1. 5 km with accurate detection. The combination of various electromagnetic technologies can achieve multi-scale detection within a depth of 10 km and realize the effect of telescope-magnifier-microscope. It also pointed that the future direction of electromagnetic method is in terms of equipment, data processing and big data information.