A new emergent alpine front chain in central Tunisia (Maktar area): filtering gravimetric data contribution

Abstract

A residual anomaly gravity map of the Maktar area has been processed via several methods including horizontal gradient, upward continuation, and Euler deconvolution to highlight structures hidden by sedimentary cover. These methods reinforce the existence of several faults inferred from geologic studies. This work outlines deep or near-surface faults that had remained hidden until now. The most important set of these faults is NE–SW trending, with depths in excess of 3,000 m. These faults limit the Northwestern limb of Balouta massif and restrain the Northwestern side of Oued Ousafa syncline. This last fault presents a thrust front which constituted the western continuity of a southern Tunisian thetys margin and a western Zaghouan scar prolongation. E–W striking faults refer to an arched beam of faults limiting Kessera plateau and others situated in the northern part of the Maktar plateau. N–S and NW–SE directions correspond to branches of less-apparent importance. Superposition of local maxima specifies dipping vergence of different proven structures. Results from this work show the importance of gravimetric data analysis in Maktar area and provide new insight into Central Atlas Tunisia structure such as new emergent segment front Alpine chain. The proposed map could be a basis for planning future hydrogeological and petroleum research in this region.