Evidence for a new regional NW–SE fault and crustal structure in Tunisia derived from gravity data

Abstract

A new Tunisian gravity map interpretation based on the Gaussian filtered residual anomaly, total horizontal gradient, and Moho discontinuity morphology established from gravity data exhibit a new regional northwest–southeast fault extending from Eastern Kairouan to Ghardimaou (Algeria–Tunisia Boundary). It presents a horizontal gradient maximum lineament that terminates the north–south Jurassic structures in the Kairouan plain. Further, this interpretation reveals other known fault systems and crustal structures in Tunisia. The new regional northwest–southeast fault constitutes with the north–south axis and Gafsa–Jefara faults the deepest faults coinciding with the Moho flexures, which had an important role in their initiation. They constitute the border intra‐continental crust faults of the Mesozoic rift. The newly recognized deep fault has critical implications for mineral and petroleum perspectives.

New Insights into Geodynamic Evolution of the South-Eastern Termination of the Tunisian Atlas during Early Cretaceous Period from Surface and Subsurface Data: Hydrogeological Implications

“…It results accumulation of continuous and thick series in the NE part (3000 m thick of deposits) and reduced ones in the SW province in which the total thickness of the Jurassic and Early Cretaceous series does not exceed 1600 m [46]. This architecture has been highlighted and proven by Said et al, [47,48] and Arfaoui et al, [45]. These two authors have confirmed that these major faults signed, during the Late Triassic to Early Cretaceous, the initiation and the accommodation of the Tethyan rifting inducing a complex system of horst and graben structures.…”

“…From North to South, Burollet [40], Abbès et al [41], Boccaletti et al [42], Dolglioni et al [43], Martinez et al, [44], and [45]) demonstrate that this architecture has been proven on all the different branches of the N-S Axis. Furthermore, this master lineament constitutes a sedimentary limit between two domains, which have different palaeogeographic settings, the Atlas zone, with very thick Lower Cretaceous formations, and the Eastern platform, characterizing a slow subsidence, during this period.…”

“…Furthermore, this master lineament constitutes a sedimentary limit between two domains, which have different palaeogeographic settings, the Atlas zone, with very thick Lower Cretaceous formations, and the Eastern platform, characterizing a slow subsidence, during this period. Arfaoui et al, [45] denote that this alignment formed a palaeogeographic feature since the Jurassic as the reductions or condensations of the sedimentary sequences often show gaps and discordances.…”

Thick‐skinned tectonics within the intracontinental easternmost Atlas foreland‐and‐thrust belt (Tunisia): Meso‐Cenozoic kinematics and implications for regional geodynamics

“…The total horizontal gradient maxima [ Blakely and Simpson , ] for different upward continuations (4, 6, 8, 10, and 12 km) were determined in order to localize deep‐seated geological boundaries (Figure ). This edge detection technique provided significant insights in delineating faults due to the subsurface contrasting densities [ Cordell and Grauch , ; Amiri et al , , ; Hamdi‐Nasr et al , ; Sarsar‐Naouali et al , ; Dufréchou et al , ; Jallouli et al , ; Arfaoui et al , ; Inoubli et al , ]. Taking into account the assumption that the more we upward continue the gravity data, the more we highlight deeper structures [ Jacobsen , ], the master fault system is traced along the horizontal gradient maxima of upward continuations 8, 10, and 12 km.…”

Contribution of Gravity Data for Structural Characterization of the Ifni Inlier, Western Anti-Atlas, Morocco: Hydrogeological Implications

“…The Horizontal Gradient filter transforms the inflection point of the residual gravity profile into a positive anomaly whose maximum coincides with the fault location, while the Tilt derivative filter is used to confirm the fault position [26][27][28][29][30]. Finally, the Euler deconvolution is applied to determine the fault depth of rooting [17,28,[31][32][33][34][35][36]. The obtained results are used to establish a comprehensive structural map of the study area, which is analyzed in conjunction with all the available geological, structural, and drilling data to identify areas favorable for groundwater drilling.…”