Two orthogonal extensional systems produced the extensional collapse of the Tell and Atlas thrust belts in northern Tunisia during the Late Miocene to Pliocene in a context of NW‐SE plate convergence between Africa and Eurasia. The older extensional system shows several low‐angle normal faults (LANFs) and associated high‐angle faults with ENE‐directed transport that produced half‐grabens and hanging‐wall syncline basins during the late Tortonian to Messinian. The direction of extension swinged towards the SE during the Messinian, cutting into, and tilting the previous detachments. Extension was accompanied by the extrusion of 8‐Ma rhyodacites and Messinian basalts, together with the development of mineralized fault breccias. Plio‐Quaternary NW‐SE directed shortening formed inversion arrowhead structures, reverse faults, refolded extensional rollover anticlines and folded the LANFs. ENE‐directed extension is concomitant with the opening of the Tyrrhenian basin. We consequently think that both processes are related and that tearing of the Calabrian slab along the northern Tunisia coast drove the ENE‐directed extension. Meanwhile, the SE‐directed extension that followed was probably related to SE‐directed peeling back of the Tunisian continental lithospheric mantle during NW subduction of the Maghrebian margin. This extension propagated eastwards from the late Tortonian until the Pliocene following the SE migrating subduction front and favored by lateral slab tearing along the Tunisian Atlas dextral Subduction Transfer Edge Propagator boundary. This new hypothesis for the tectonic evolution of northern Tunisia shows for the first time the importance of crustal extension in the denudation of the Tunisian Atlas and Tell foreland thrust belts and its relation to deep mantle tectonic mechanisms.

Exploration of territories not previously analyzed by landslide experts provides interesting findings. The Chgega landslide, in northern Tunisia, represents a paradigmatic mass movement. It can be classified as a complex landslide, or more specifically as vast rock spreading that evolved into a block slide. It involves a great block of limestone—about 900 m long and 400 m wide—sliding over ductile clays and marls. The viscoplastic creep of the clays drives the landslide and creates, in its crown, a graben ~800 m long and ~120 m wide that breaks the summit of Chgega Mountain. Using Interferometric Synthetic Aperture Radar (InSAR) technologies, we demonstrate that this complex landslide is currently active and moreover shows progressive movement without clear episodic accelerations. The velocity of the limestone block is just above 2 mm/yr. The occurrence of gravity-induced joints indicates that the movement has an orientation towards 333° of azimuth on average, conditioned by the landscape around Chgega. These results were obtained through the analysis of a 3D model and a high-resolution orthoimage created from photographs acquired by an Uncrewed Aerial Vehicle (UAV). We may conclude that the landslide movement is determined by normal faults with directions N060°E and N140–150°E. This characterization of the Chgega landslide can serve as the basis for future studies about the origin of this slope movement. Furthermore, the data provided here may support the recognition of Chgega as a singular geological point that deserves to be declared a geosite.

Cenozoic extension in the Western Mediterranean has been related to the dynamics of back‐arc domains. Although, in most of its orogenic belts extension propagated into the fore‐arc nappe domains. Here we revisit the structure, metamorphism and radiometric ages of the Tunisian Tell, where HP/LT rocks (350°C at 0.8 GPa), were exhumed by the sequential activity of extensional detachments after heating and decompression (410°C–440°C at 0.6–0.3 GPa) in a plate convergent setting. Normal faults thinning the Tunisian Tell detached at two different crustal levels. The shallower one cuts down into the Atlas Mesozoic sequence, involving Tellian Triassic evaporites in the hanging‐wall forming halokinetic structures in the Mejerda basin late Miocene. The deeper‐detachment bounds metamorphic domes formed by marbles and metapsammites from the Atlas domain. Illite crystallinity on Triassic rocks shows epizonal to anchizonal values, at deep and intermediate structural depths of the Tell‐Atlas nappe belt, respectively. New U‐Pb 49.78 ± 1.28 Ma rutile ages from Tellian metabasites, together with existing phlogopite 23–17 Ma K‐Ar ages in Atlas marbles from the footwall of the deepest detachment, indicate a polymetamorphic evolution. The Tell rocks underthrusted the Kabylian flysch in the early Eocene. Further, early Miocene shortening thrusted the metabasites over lower‐grade sediments, producing HP/LT metamorphism and ductile stretching at the base of the Atlas belt. The exhumation of midcrustal roots of Western Mediterranean nappe belts after tectonic shortening is a common feature related to tearing at the edges of the subduction systems and inboard delamination of their subcontinental lithospheric mantle.