Over this large region there are extensive areas of basaltic flows, notably southeast of Azrou, with numerous volcanic centres including maars and particularly abundant scoria cones (Gentil, 1916; Harmand and Cantagrel, 1984). Some individual flows are confined to valleys along which they may extend for tens of kilometres. Among these rocks are alkaline varieties which are described under the general term 'ankaratrite' by Jérémine (1955), meaning melanocratic olivine nephelinite. She lists varieties containing analcime, hauyne and, with one example only, melilite. An occurrence in the south of the area contains phenocrysts of olivine in a groundmass of augite and aegirine-augite, biotite, brown amphibole, nepheline and analcime. A melilite-bearing rock occurring in the volcano of Djebel Anach (Termier, 1936) comprises altered olivine, augite, melilite, perovskite, magnetite, brown amphibole, a little apatite, nepheline and 'primary' analcime. Termier (1936) describes in detail hauyne-bearing rocks which also contain altered olivine together with augite, nepheline, rare biotite and magnetite and these are found at a number of localities (Jérémine, 1955, Fig. 2). To the south of Azrou, 10 km southeast of Ain Leuh, Termier et al. (1948) describe a suite of rocks from the Talzast volcano which comprise ankaratrite, consisting of olivine, augite, biotite, nepheline, accessories and, in some varieties, hauyne, and a coarse rock which is referred to as talzastite. The last is an ijolite with Ti-augite, a chemical analysis of which is given by Cherotzky (1969); specimens dated by Harmand and Cantagrel (1984) are described as melanephelinite, micromelteigite and ijolite.