A stratigraphic study of the penibetic and subbetic series shows that the two are quite different. The subbetic--northern Boyar corridor--includes a well-developed Liassic with marly facies, a red nodular Tithonian, a Cretaceous, and a limestone-marl Eocene. In the penibetic, southern part of the Boyar corridor, the middle and upper Jurassic contain limestone units with coralligenous facies; and the middle Cretaceous is directly transgressive on the Tithonian limestones. The two series correspond to two distinct sedimentation regimes. Comparison of the different beds in the area indicates that the beds of the Los Majales and Fresnillo chains belong to the same stratigraphic and tectonic unit whose facies are totally different from the subbetic and are only slightly analogous to the penibetic. The northward thinning of the penibetic and the presence of Aptychus breccias and Tithonian belemnites in the Penon Grande area indicate the progressive passage of the penibetic into the Majales-Fresnillo beds which override the subbetic. These beds may have originated either from a zone between the penibetic and the Malaga nappe, or from a region more to the south in the sedimentation domain of the flysch nappes.