## 2 Geological Background  
The Bou Azzer-El Graara Inlier (BAEI) (Figure 1A-C) is linked with two nearby depressions, Bou Azzer then El Graara, situated 45 km southwest of Ouarzazate city. It spreads approximately 20 km from Taznakht to Bleida in a WNW-ESE direction. The Tissoukine and Tasla smyelines surround it from the north and south, respectively. The BAEI was formed during the excavation of the Anti-Atlas Major Accident (AAMA), representing an amount of the earliest Pan-African seams. In the southern inlier part, the Tachdamt-Bleida Set, it is thought that remains of the Tonian platform came into existence on the northern border of the West African Craton (WAC). Based on recent tectonic and lithological classifications along with newly acquired geochronological information, it encompasses the most ancient rock formations within the BAEI. During this period of rifting, there is a distinctive emission of tholeiitic to alkaline basalts, initially approximated at 788 \(\pm\) 10 Ma and more lately, around 883 Ma [13]. The Assif n'Bougmmane-Takroumt complex's metamorphic rock formations stretch from west-northwest to east-southeast. These formations create separate elevated areas in Bou Azzer, Tazigzaout, Oumlil, and the primary elevated region of the Bougmmane massif situated in the Takroumt region, located north of the Tachdamt-Bleida group. These metamorphic rocks were previously thought to belong to the Paleoproterozoic (PI) basement. However, recent geochronologic data suggest that they are younger and are now attributed to Cryogenian dates [14; 15]. They consist of amphibolites, metagabbros, augen gneiss, and micaschists in their lithology [15]. The protoliths of these rocks have geochronological dates ranging between 730 million years and 752 million years ago within the Tazigzaout Complex [17], and from 745 million years to 755 million years ago in both the Bou Azzer massif and the Oumlil massif [15]. Furthermore, there are extra geological characteristics, including a mafic intrusion within the Bougmmane Complex established 700 million years ago, along with two veins of micas leucogranadiorite in the Tazigzaout massif, dated at 705 million years ago and 701 million years ago [18], and another at 695 Ma in the Oumlil massif, which all cross-cut these rocks [15]. These findings suggest that an orthogeneissification event occurred earlier than 700 Ma during the Lower Cryogenian period. Similarly, to the northeastern side of the BAEI, within the Tichibanine-Ben Lgrad area, one can find rocks formed from volcanic arcs, including rhylolites, microgabbros and  
Figure 1: The location of the studied area (Bou Azzer inlier) at (**A**) The West African Cration level modified after [16] and (**B**) at the Anti-Atlas level modified after [16]. (**C**) Geological map of the study area modified after [15]. basalts, alongside volcano-sedimentary formations like cinerites, sandy siltstones, dacite and felsic tuffs. The dating of the dacite and felsic tuffs, using U/P on zircon, reveals ages of 767 million years and 761 million years, respectively [19]. Ref. [20] was the first to characterize the famed Neoproterozoic supracrustal ophiolite found at BAEI. It is composed of ophiolite slices from ultramafic to mafic, connected to melanges of volcanic sediments that have been invaded by intrusions related to subduction [21]. Ultramafic cumulates of wehrlites, harzburgites and dunite lenses, and clinopyroxenolites, a crustal gabbroic unit's section, basaltic pillow lavas a complex of sheeted dykes are all parts of the BAO series. The BAO and the Khzama orb in the Siroua window are examples of the pan-African oceanic lithosphere, which was thrust onto the northern boundary of the WAC (West African Craton) as stated in reference [22]. Its precise age remains a topic of debate despite various speculative indirect estimates [16]. However, the Khzama plagiogramite within the Siroua ophiolite provides the most accurate age estimation for the Central Anti-Atlas ophiolite, pinpointing it at 762 million years old [23].