Resistivity Imaging Of A Partially Reclaimed Coal Tailings Pile

An electrical resistivity investigation was conducted at a partially reclaimed valleyfill<br>coal tailings pile in southeastern Ohio to determine the tailing thickness and to evaluate<br>the variation within the fill material. The study concentrated on a former slurry pond at the<br>Flint Run site. Dipole-dipole arrays were used to generate apparent resistivity<br>pseudosections with a station spacing of 5 m and a maximum dipole separation (n) of 6.<br>The pseudosections were inverted with a least squares method to produce resistivity<br>images of the pile to depths of 30 m along 870 m of profile lines. Comparison of the<br>images to data borehole lithology and conductivity logging shows strong correlation<br>between the occurrence of coal tailings and acid mine drainage (AMD) saturated waste<br>rock (as opposed to consolidated siltstone and sandstone) and resistivity lows. The<br>saturated coal and waste rock appear as resistivities below 20 Rm; consolidated siltstone<br>and sandstone appear as resistivities above 50 Rm. The slurry dam is seen in the images as<br>a resistivity high and the tailings in the former slurry pond are seen to increase in thickness<br>and/or depth consistent with the historical drainage.