## 4 Lithostriagraphy  
### Tazzouguerte Section  
The Tazzouguerte section is located to the east of Ksar Tazzouguerte. In this locality, the Cretaceous series (Figure 3a) lies on Jurassic deposits [25]. The lower part of this series is poorly visible because it is covered. This part of the series, which is more than a hundred meters thick, would correspond to fine-grained sandstones with oblique and planar stratifications of the Jbel Sidal and Ifezouane formations. The section begins with a thick variegated fine-grained unit (49 m; Figure 3b), which starts with green marks and red clays (0-8.5 m). From 8.5 to 15.5 m, beds are poorly visible due to talus scree. The top of this fine-grained resistant unit comprises clays and marks alternating with decimetric primary gypsum beds and yellowish sandstones or calcareous sandstones (15.5-49 m). This part of the section corresponds to the Aoufous Formation [2] and is attributed to the Cenomanian [9; 14; 17; 27; 32]. At 49 m, a facies change is marked by the presence of a limestone succession with a total thickness of 198 m. It can be divided into four carbonate and resistant units separated by three softer and erodible less-resistant units (Figure 3a). Figure 2: Graphic legend for columnar sections presented in this work. The first resistant unit (49-73 m) begins with dolomitic limestones and is followed by a bivalve bioclastic limestone level (64-66.5 m); bioclastic wackestones showing the shells a foliated internal structure (Figure 4a); and limestones (wackestone-packstone) with lamellibranch, echinoid, and ostracod bioclasts (Figure 4b). The top of the resistant unit consists of bioturbated dolomitic limestones. This first resistant unit is surmounted by an interval (73-84 m) consisting of thin-bedded and fine-grained limestones with bivalve shells (Figure 3c). Figure 3: Taxzouguerte section. (**a**) general view, along an east-west direction, showing the logged section; (**b**) variegated facies of the Aoufous Formation and the limestones of the Akrabou Formation; (**c**) fine limestone with bivalve shells; (**d**) limestone with rudists; (**e**) gastropod bioclastic limestone; (**f**) surface with bivalve shells; (**g**) limestone with silicified shell assemblages; (**h**) bedded limestone by on a lumachelic level; (**i**) fine limestone with chert nodules. Figure 4: Thin section photographs of limestone microfacies of the Akrabou Formation in the Tazzouguerte section. (**a**) wackestone microfacies with bivalves (bv); (**b**) bioclastic wackestone to backbone with bivalves (bv); (**c**) bioclastic wackestone with gastropod (g) and bivalves; (**d**) details of a rudist shell (r); (**e**) bioclastic wackestone to packstone with benthic foraminifera (bf); (**f**) packstone microfacies with bivalves (bv) and algae (al). The second resistant unit (84-104 m), begins with bioclastic limestones with diverse fossiliferous content, mainly corals, echinoids, and crimoids. It grades to coral limestones, followed by limestones. The resistant unit ends with limestones containing gastropods and echinoids overlaid by a thick interval (104-147 m), which begins with fine-grained limestones with bivalve and gastropod shells. Its middle part is composed of bioclastic limestone that is very rich in rudists, gastropods, and bivalves (Figure 3d). The microfacies correspond mainly to wackestone to packstone with a wide diversity of organisms (Figure 4d). The interval ends with limestones rich in thick gastropods. The third resistant unit (147-162 m) is composed of a loaf-shaped limestone containing small bivalve shells alternating with lumachellic levels composed of thick bivalves (Figure 3f). This resistant unit is followed by a new interval (162-210 m) that begins with fine-grained limestone with stratiform and nodular chert overlying a bedded limestone with shell-rich levels (Figure 3g). This is a wackestone-to-packstone limestone with bivalve and gastropod bioclasts (Figure 4c). Above, a massive whitish limestone is deposited, followed by loaf-shaped limestones.