Rémi Charton , Giovanni Bertotti , Aude Duval-Arnould, Joep E.A. Storms, Jonathan Redfern

Continental passive margins and their hinterlands in the Atlantic realm are the locus of a significant amount of studies that evidence pre-, syn-, and post-rift episodic km-scale exhumation and burial episodes. We submit a 3-steps workflow to obtain 1) exhumation/burial rates, 2) eroded material flux, and 3) paleoreconstructions of source and sink domains. We apply this workflow in onshore NWAfrica from Permian to the Present-day.
Our synthesis of available time-Temperature (t-T) modelling results predicts high exhumation rates in the Anti-Atlas (0.1 km/Myr) during the Early to Middle Jurassic, and in the High Atlas (0.1 km/Myr) and Rif (up to 0.5 km/Myr) during the Neogene. These rates are comparable to values typical of rift flank, domal or structural uplifts settings. During the other investigated periods, exhumation rates in the Meseta, High-Atlas, Anti-Atlas, and Reguibat shield are around 0.04±0.02 km/Myr.
The exhumation rates are then used for interpolation at the regional scale, in order to subsequently calculate the volume of rocks eroded during the exhumation episodes. Estimates of eroded material fluxes are between 0.2x10^3 and 7.5x10^3 km3 (in the Meseta and the Reguibat Shield, respectively).
Ten erosional (quantitative, from interpolation results) and depositional (qualitative, from data synthesis) “source-and-sink” maps have been constructed. Emphasis is placed on the Jurassic and Cretaceous periods comprising six source-and-sink maps. The maps are based on the extent of exhumed domains, geological maps, lithofacies from onshore and offshore basins, biostratigraphic data, new geological fieldwork, and well data. The results illustrate changes in the source-to-sink systems and allow for a better understanding of the Central Atlantic margin hinterlands evolution.