Electrical Resistivity Characterization of a Reclaimed Gold Mine to Delineate Acid Rock Drainage Pathways

An electrical resistivity survey was completed at the Landusky mine. The survey consisted of 15 lines on the surface of the reclaimed Suprise pit, Queen Rose pit, and the region immediately south of Swift Gulch. Additionally, wells and seeps were used by energizing electrodes in direct contact with ground water to increase the sensitivity of the resistivity method at depth. The survey was conducted to locate potential acid rock drainage pathways that are contaminating Swift Gulch. The results showed that the lowest resistivity values were coincident with the Queen Rose pit. Furthermore, the low resistivity feature appeared to trend northeast along a known fault, consistent with the geologic understanding of the site. A scatter plot of resistivity values versus total dissolved solids (TDS) showed a strong correlation (R-2 = 0.85). A linear regression model suggests TDS at the lowest resistivity region to be approximately 2.5 times greater than that measured in ground water wells.