The Mauritanide Orogen and Its Northern Extensions (Western Sahara and Zemmour), West Africa

Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa

“…This narrow (<100 km) belt is classically regarded as a polyorogenic domain that was thrust onto the West African craton in late Paleozoic times (Sougy, 1962). Following regional studies (Chiron, 1973;Lécorché, 1980;Le Page, 1983, 1986, 1988Dia et al, 1979;Dia, 1984;Villeneuve, 1984;Martinez, 1988;Lécorché et al, 1989Lécorché et al, , 1991 have pointed out the different characteristics of the Mauritanide, Bassaride and Rokelide orogenic segments. In contrast with the northern Mauritanides where klippen of crystalline rocks are directly thrust onto the Neoproterozoic to early Paleozoic cratonic cover of the WAC, the internal zones of the Central Mauritanides comprise a variety of metamorphic terrains that sharply contrast with the external, non-metamorphic foreland.…”

The Variscan Belt

“…References: Concerning the Mauritanides as a whole, some of the most recent and significant papers are those by Lécorché et al (1991), Burg et al (1993), Villeneuve & Cornée (1994), and Le Goff et al (2001). The Awsard sheet of the geological map of Morocco, scale 1:50,000 (Rjimati & Zemmouri, 2002) and the paper by Villeneuve et al (2006) concern particularly the Adrar Souttouf segment.…”

“…However, the Mauritanide thrust emplacement onto the craton corresponds to a late, low-temperature phenomenon, which was dated at ∼ 310 Ma (K-Ar and 39 Ar-40 Ar datings) on samples from the nappes and from the sedimentary autochthon in the central and southern parts of the belt (e.g. Lécorché et al, 1991). At the northern tip of the belt, i.e.…”

Geologic and Metallogenic Framework of North Africa

“…The ASM consists of allochtonous Precambrian and lower Paleozoic stacked nappes that were thrust eastward onto the WAC during the Mauritanide orogeny. These nappes lie either directly on the basement in the south and southwest, or on a thin sequence of Upper Ordovician to Devonian foreland rocks in the southeast (Lécorché 1980;Lécorché et al 1991). Metamorphic grade of the nappes ranges from lower greenschist facies to granulite facies (Sougy and Bronner 1969;Lécorché et al 1991).…”

“…These nappes lie either directly on the basement in the south and southwest, or on a thin sequence of Upper Ordovician to Devonian foreland rocks in the southeast (Lécorché 1980;Lécorché et al 1991). Metamorphic grade of the nappes ranges from lower greenschist facies to granulite facies (Sougy and Bronner 1969;Lécorché et al 1991). Contained strata vary from metasedimentary and metavolcanic rocks to high-grade migmatite, mica schist, and gneiss.…”