Spectral-induced polarization characteristics of rock types from the skarn deposit in Gagok Mine, Taebaeksan Basin, South Korea

Spectral-induced polarization (SIP), which measures the responses to alternative current of multi-frequencies below 1 kHz, is an excellent technique for exploring the economic minerals in the ore deposits. However, the studies on the SIP characteristics of rocks from ore deposits have rarely been conducted due to the decline of mining activities. For effective exploration, the SIP responses of in situ rocks should be recognized first. Therefore, this study was conducted to understand the characteristics of the SIP responses depending on the rock type using the laboratory measurements. Rock samples were obtained from both host rocks and skarn rocks in the Gagok Mine which is a typical skarn deposit in South Korea. The responses of the host rocks, which include dielectric minerals, were found to depend on the induced polarization (IP) effect of the compact layer. In contrast, the responses of the skarn rocks, which were mixtures of dielectric and metallic minerals, depended on the IP effect of the diffuse layer. This study clearly demonstrates that SIP responses are determined by the electrochemical characteristics of the composing minerals.