Neogene exhumation of the Marrakech High Atlas (Morocco) recorded by apatite fission‐track analysis

Abstract

Apatite fission‐track (AFT) data have been obtained along a traverse across the Marrakech High Atlas to constrain its tectono‐thermal evolution. AFT ages vary between 212 ± 15 Ma and 20 ± 4 Ma. An Early Miocene AFT age accompanied by long mean track length from the central part of the chain has been interpreted as the timing of the main inversion of this region with the creation of relief because of the shortening induced by the interplay between the African and Eurasian plates. Thermal modelling of samples collected south of the South Atlas Fault Zone indicates a Middle‐Late Miocene or even later cooling that has been attributed to the component of the uplift of the chain related to the thermal anomaly present beneath the Atlas Mountains.

Post-rift vertical movements and horizontal deformations in the eastern margin of the Central Atlantic: Middle Jurassic to Early Cretaceous evolution of Morocco

“…A significant amount of low-T geochronological studies has been performed in the High Atlas during the last years (Missenard et al 2008;Balestrieri et al 2009;Ghorbal 2009). Because of the lithological limitations imposed by the Apatite Fission Track and (U-Th)/He methods, practically all samples measured by the different authors originate from the MAM and, more specifically, from the Paleozoic basement and its stratigraphic cover of Triassic continental deposits.…”

The three main steps of the Marrakech High Atlas building in Morocco: Structural evidences from the southern foreland, Imini area

“…times (following Tesón et al, 2010;Aït Ouglif Formation age) witnessed the earliest recorded structural deformation and the development of the topography. This is shown by: (1) the setting of the various "nappes" across the High Atlas of Marrakech and the Central High Atlas (Laville et al, 1977; this study), (2) the influx of the unconformable detrital deposits of the Aït Ouglif formation (El Harfi et al, 2001), (3) the resuming of deformation, as suggested by a structural study of Tesón and Teixell (2008) and (4) the record of an important exhumation within the Marrakech High Atlas Balestrieri et al, 2009).…”

“…Following the studies of Missenard et al (2008) and Balestrieri et al (2009), based on lowtemperature thermochronology (LTT), we suggest that this Early(? )-Middle Miocene exhumation is linked to lithospheric thinning at that time (i.e.…”

“…This particularity significantly challenges the reconstruction of a proper tectonic calendar in Morocco. The complexity of this calendar is also highlighted by the apparent contradiction between (1) the post-Messinian surface uplift evidenced by Babault et al, 2008 and (2) the Early Miocene in age denudation recorded by thermochronological data Balestrieri et al, 2009).…”

Provenance of the heavy mineral-enriched alluvial deposits at the west coast of the Red Sea. Implications for evolution of Arabian–Nubian crust

“…Therefore, it seems less likely that the alluvial fans have significant contribution from other parts of the Red Sea coast by longshore currents. The denudation and erosion of the Eastern Desert have been investigated using apatite fission track dating (e.g., Omar and Steckler, 1995;Bojar et al, 2001;Abbate et al, 2002;Balestrieri et al, 2009). This dating indicates that the Arabian-Nubian Shield underwent uplift in two stages, an early uplift stage in the Oligocene (±35 Ma) and a later major uplift period in the Miocene (20)(21)(22)(23)(24)(25).…”