Reconstructing Extensional Basin Architecture and Provenance in the Marrakech High Atlas of Morocco: Implications for Rift Basins and Inversion Tectonics

Abstract

The Moroccan Atlas developed through a multiphase tectonic history including Permian‐Jurassic continental rifting and Cretaceous‐Cenozoic intracontinental shortening. New detrital zircon (DZ) U–Pb geochronologic results from the Ourika‐Zat region in the Marrakech High Atlas constrain the sediment provenance of prerift sediment sources and synrift and postrift basin fill. Prerift Precambrian‐Cambrian units contain Neoproterozoic DZ from the Pan‐African orogeny. Ordovician rocks contain diagnostic 0.95‐ to 1.28‐Ga DZ that are absent in the West African Craton, suggesting distal sediment sources. Permian rift basin fill contains Permian zircons that constrain maximum deposition age and diagnostic of northern Meseta domain sediment sources. New mapping and cross‐section construction demonstrate that Permian basin fill accumulated in a half‐graben above a southward dipping normal fault that likely guided subsequent inversion. Triassic rift basin fill thickens southward, above a likely northward dipping normal fault. The change in rift basin geometry was accompanied by catchment reorganization, the introduction of southern rift flank sediment sources, and subbasin integration. The southern catchment expanded to encompass Meso‐Archean rocks of the Reguibat Shield situated >800 km southward. Existing and new provenance results from postrift strata document onset of recycling of Atlas rift basin fill during the mid‐Cretaceous and before the onset of compressional inversion. These results highlight the interaction between deformation and sediment routing in an extensional basin and sediment dispersal patterns across continental margins during multiphase deformation. Stratigraphic, structural, and provenance characteristics reveal that the Atlas rift shares similarities with high‐angle and supradetachment basin models, emphasizing the diverse nature of extensional styles.

Late Miocene Deformation Kinematics Along the NW Zagros Fold‐Thrust Belt, Kurdistan Region of Iraq: Constraints From Apatite (U‐Th)/He Thermochronometry and Balanced Cross Sections

“…Later after inversion, these structures possibly influenced the spatial configuration of the latest Oligocene marine basin margin, the basement‐involved out‐of‐sequence structures, and the present‐day MFF position. Inherited structural weakness zones have been shown to influence the timing, location, and style of later deformation (e.g., Bosworth et al, 2008; Kley et al, 2005; Nem č ok et al, 2013; Perez et al, 2016, 2019). Therefore, the geometry of the proposed deeply rooted basement faults in the cross sections of this study is plausibly linked to inversion of normal faults (Jackson, 1980), similar to shortcut faults in the Lurestan area of Iran (Tavani, Corradetti, et al, 2018; Tavani et al, 2020; Tavani, Parente, et al, 2018).…”

Integrated multi-proxy source-to-sink analysis of the Lower Cretaceous of the Essaouira-Agadir Basin.

“…All these populations indicate that the ultimate source for these sediments was the WAC (Abati et al, 2010;Avigad et al, 2012;Gärtner et al, 2017). From Permian times onwards, Variscan grains also form an accessory population indicating that the Meseta and MAM were also a sediment source during the Mesozoic and Cenozoic (Perez et al, 2019).…”

“…However, the group is surrounded to the north, east and south by sections sharing a high degree of similarity together, and the peculiar fingerprint of the Tamri group is unlikely to be the result of a different regional provenance, but more likely the result of local sediment sources (possibly from the Cap Ghir palaeohigh) or the result of hydraulic sorting. 2017)) in the basal Triassic (Perez et al, 2019, Domènech et al, 2018) or a major one (Upper Triassic of Oukaimeden and Tizi N'Test (Perez et al, 2019, Domènech et al, 2018).…”

“…The detrital record of Morocco also records zircon populations which span the Mesoproterozoic (1.6-1.0 Ga) (Accotto et al, 2019;Azdimousa et al, 2019;Ghienne et al, 2018), despite there being no known basement rocks in the WAC that could act as a source for zircons of this age range. Several sources have been proposed for these grains, including the Amazonian Craton Sunsás Belt (Perez et al, 2019), the Taoudeni Basin (Azdimousa et al, 2019;Gärtner et al, 2018), the Arabian-Nubian Shield or Sahara-Meta Craton (Accotto et al, 2019;Marzoli et al, 2017), or hitherto unknown Mesoproterozoic basement in NW Africa (Ghienne et al, 2018). These Mesoproterozoic zircons first appear in the Middle Cambrian (Avigad et al, 2012), becoming up to 30% of the zircons found within Hirnantian glacial deposits (Ghienne et al, 2018).…”

Low‐temperature thermochronology as a control on vertical movements for semi‐quantitative source‐to‐sink analysis: A case study for the Permian to Neogene of Morocco and surroundings

“…Sediment provenance analysis conducted in Morocco and surroundings are scarce. Five recent works investigated the provenance with detrital zircon U-Pb (Azdimousa et al, 2019;Domènech et al, 2018;Marzoli et al, 2017;Pratt et al, 2015;Perez et al, 2019); one study used traced elements and radiogenic Nd-Sr isotopes (Ali et al, 2014), one using neodymium isotopes and major/trace elements from DSDP wells (Mourlot et al, 2018), and one produced detrital LTT ages (Sehrt, 2014). Several studies have also documented palaeocurrent directions in fluvial systems (e.g.…”