Geology
2.1 Geological Setting
Morocco is located at the northwestern passive continental margin of Africa, locally
referred to as Maghreb (Arabic: ‘west, occident’; Figs. 2.1 & 2.2). It hosts mainly
variably deformed to undeformed Mesozoic sedimentary cover rocks. Highly
deformed Paleozoic basement crops out in the south (Anti-Atlas) and in isolated
inliers north of it in the Meseta domain (Massif Central, Jebilet and Rehamna massifs)
and the Central High Atlas (Massif Ancien) (Figs. 2.1 & 2.2). The Anti-Atlas also
hosts small inliers of Precambrian basement.
2.1.1 Regional Tectonostratigraphic Overview
Morocco was affected by two orogenies, the Hercynian or Variscan orogeny in the
Carboniferous, and the Alpine/Atlasic orogeny in the Tertiary (Hercynian after the
Harz Mountains of Germany; Variscan after ‘Curia Variscorum’, the Bavarian city of
Hof; both terms are used equally in the literature). Intermittent rifting occurred from
the Permian to the Lower/Mid Liassic. The Hercynian orogeny was related to the
assembly of the supercontinent Pangea, and the rifting to its demise.
2.1.1.1 Paleozoic
Hercynian Events
The area of Morocco’s Atlantic basins originated as part of the submerged
northwestern passive margin of the southern continent of Gondwana. The mainly
silty-muddy Paleozoic lithologies point to an outer shelf setting. During the Hercynian
terminal collision between Gondwana and Laurussia (Old Red continent), the shelf
was telescoped into a west-northwest facing fold-and-thrust belt but its
tectonostratigraphy is not well constrained (e.g. Piqué 2001, Michard et al., 2010).
The now peneplained thrust belt is most coherently exposed in the Massif Central (Fig.
2.2). While it is referred to Zizi (2012) for a more detailed treatment of the Hercynian
crustal dynamics, a tectonic correlation of the Meseta domain with its European
counterpart is attempted in the following.