Abstract

Micro-gravimetry emerges as the most appropriate geophysical technique for cavity detection in urban or industrial settings, as it remains unaffected by surrounding electromagnetic influences. The presented study investigates the occurrence of fissures, land subsidence, collapse events, and their potential association with the formation of cavities at depth. These phenomena were observed near a sealed hydraulic drilling site located in the M’Rara area within the Northeast Algerian Sahara basin. This drilling operation was sealed off due to the inflow of saline water, with a salt layer identified at a depth of 936 m according to the stratigraphic column. A gravimetric survey was conducted to image the lateral and vertical density variation. The resulting gravimetric image allows in comprehending the observed geological phenomena and their potential correlation with the presence of cavities at the salt layer.