Gravity Data Contribution for Petroleum Exploration Domain: Mateur Case Study (Saliferous Province, Northern Tunisia)

Triassic salt structures which are interesting for hydrocarbon exploration are widespread in northern Tunisia. A good knowledge of these structures’ evolution and geometry is required for prospection programs. In oil exploration, seismic method is the most adequate approach used to explore subsurface; the seismic quality deteriorates within salt provinces, so that gravity becomes more suitable. In this context, the present case study focuses on the interpretation of geological and computed gravity ground data to infer more accurate picture on the Triassic salt structures in Mateur region (northeastern Tunisia). First Vertical Derivative, Total Horizontal Derivative, and Total Horizontal Derivative of the tilt-angle maps were computed from the complete Bouguer anomaly to decipher fault patterns by enhancing shallow structures and approximating edges of source bodies. Euler Deconvolution and spectrum analysis are also elaborated to estimate the burial depths of delineated structures. Transformed maps highlight, nearby the Lansarine–Baouala Triassic outcrops, the presence of circular gravity lineaments around positive anomalies that reflect the shape of concentric faults edging Triassic subsalt features. Causative source depths of these anomalies exceed 1500 m, thus indicating deep-rooted salt structures. Our results corroborate that fact that the Lansarine–Baouala Triassic outcrops form a huge diapir surrounded by large but buried subsalt dome features. The obtained results help refining the previous structural map that could be of significant use for petroleum exploration in the Mateur area.