The intermontane Tarom Basin of NW Iran (Arabia-Eurasia collision zone) is located at the transition between the Iranian Plateau (IP) to the SW and the Alborz Mountains to the NE. This basin was filled by Late Cenozoic synorogenic red beds that retain first-order information on the erosional history of adjacent topography, the vertical growth of the plateau margin and its lateral (orogen perpendicular) expansion. Here, we perform a multidisciplinary study including magnetostratigraphy, sedimentology, geochronology and sandstone petrography on these red beds. Our data show that widespread Eocene arc volcanism in NW Iran terminated at ~ 38-36 Ma, while intrabasinal synorogenic sedimentation occurred between ~ 16.5 and < 7.6 Ma, implying that the red beds are stratigraphically equivalent to the Upper Red Formation. After 7.6 Ma, the basin experienced intrabasinal deformation, uplift and erosion in association with the establishment of external drainage. Fluvial connectivity with the Caspian Sea, however, was interrupted by at least four episodes of basin aggradation. During endorheic conditions the basin fill did not reach the elevation of the plateau interior and hence the Tarom Basin was never integrated into the plateau realm. Furthermore, our provenance data indicate that the northern margin of the basin experienced a greater magnitude of deformation and exhumation than the southern one (IP margin). This agrees with recent Moho depth estimates, suggesting that crustal shortening and thickening cannot be responsible for the vertical growth of the northern margin of the IP, and hence surface uplift must have been driven by deep-seated processes.

The Atlas-Meseta intracontinental orographic system of Morocco experienced recent, large-scale surface uplift as documented by elevated late Miocene, shallow-water marine deposits exposed in the Middle Atlas Mountains. The Anti-Atlas Mountains do not present any stratigraphic records that document regional vertical movements, however, the presence of a high-standing, erosional surface, and the transient state of river networks, provides insights into the uplift history of the belt and the mechanisms that drove it. Here, we combine geomorphic and stream profiles analyses, celerity of knickpoints and linear inverse landscape modelling with available geological evidence, to decipher the spatial and temporal variations of surface uplift in the Anti-Atlas and the Siroua Massif. Our results highlight the presence of a transient landscape, and document a long wave-length topographic swell (~ 100 x 600 km) with a maximum surface uplift of ~1500 m in the Siroua Massif and ~1100 m in the central Anti-Atlas starting from ~10 Ma, in association with late Miocene magmatism in the Siroua and Saghro Massif and contractional deformation in the High Atlas. Uplift rates for the central Anti-Atlas range between 70 and 180 m/Myr, fall within the same order of the rates obtained from uplifted marine deposits suggesting a similar deep-seated mechanism of uplift most likely related to astenopsheric upwelling. Overall, our approach allows to quantitatively constrain the transient state of the landscape and the contribution of regional surface uplift on mountain building processes.