Application of electromagnetic transient method for Zn Pb exploration at the Cho Dien Cho Don District, Bac Can Province, North Vietnam

摘要

Effectiveness of transient electromagnetic method (TEM) used for the localization of Pb Zn ore bodies at the Cho Don deposit, province Bac Can, North Vietnam is appraised based on the modelling processes results. Conductive Pb Zn ore bodies hosted in high-resistive limestone are in good conditions for the application of the TEM. The modelling process relays on the calculation of the voltage decay in time domain formed from the induced magnetic field diffusing into the study medium, when a pulse current with a given frequency is flowing in a transmitting loop coil. The model results show that the power current of 1 A transmitted from the coils with 100 or 400 m of size is effective for localization of the Zn Pb ore bodies. However, the resolution and penetration depth of the TEM with a coil of L = 100 m is better and shorter in comparison with those in the case using the coil L = 400 m.