Geological Characterization of the Bir Djeneb’s Sinkhole (Boukadir, Algeria)

Abstract Bir Djeneb is one of the remarkable structures found in the Messinian Kef Formation, a vast outcrop of white Lithothamnium limestone south of the city of Boukadir. This construction remained unknown for many years. Using field research and literature analysis, we examine this phenomenon in this work. According to the most recent classifications of sinkholes, Bir Djeneb is classified as a bedrock collapse sinkhole as a result of the geological characterization. The sedimentary fill of the sinkhole allows us to distinguish between two subsidence episodes. By linking this sinkhole with a major collapse that occurred in 1988 in the midst of Boukadir's Fourth National Road, the dangerous aspect of this sinkhole was brought to light.