Historic Mineshaft and Mine Gallery Identification with 2D Electrical Resistivity Imaging (Northern Mexico)

Silver was mined around Gomez Palacio, Durango, Mexico in Colonial times. Small mining operations also occurred in historic times (the 1930s) in the La Soledad mineral claim, northwest of Gomez Palacio city. Here, historical accounts call for an unmarked, lost, abandoned mine shaft that stopped operations nearly a century ago. Vein-type and manto-type mineralization of hydrothermal origin and an abandoned mine are reported within the survey area. The present near-surface 2D electrical resistivity imaging survey was done to search for an unmarked, old, and abandoned mineshaft within the La Soledad mineral claim. The survey comprises five resistivity profiles with variable orientations, covering approximately an area of 1 square km. The smooth, robust, and damped least-squares inversion methods were used to invert the resistivity data; however, successful results are not attributed to a single inversion method. The average imaging depth is estimated at approximately 65 m. The results are satisfactory and suggest an abandoned, shallow, and small mine gallery network with two backfilled mine shafts. Low-resistivity anomalies adjacent to the high-resistivity anomalies in all profiles suggest shallow mineralization zones.