Underground gravity survey in a coal mine

Underground gravity surveys are usually conducted in order to define geological structures and to locate and delineate ore bodies. In the coal mines, on the other hand, these surveys are often applied in solving stability and safety problems of the mine. Basic principals of underground gravity measurements and examples of application in coal mining are presented. Complex geophysical and geological investigations were conducted in a wider area of the coal mine 'Trbovlje - Hrastnik' (Slovenia) in purpose to define geological features and delineate potentially dangerous zones, connected to the subsidence, rockslides and water penetrations into exploitation galleries of the mine. Gravity and microtremor measurements were conducted in the mine galleries. Compilation and interpretation of subsurface gravity anomaly maps and interval density map is presented.