The Betic Cordilleras stretch across the southern part of Iberia for about 650 km, from Cabo de la Nao (south of Valencia), in the east, to Cadiz, in the west. These Cordilleras consist of a complex assemblage of different geological domains (Figs. 1 and 2).

The External and Internal Zones correspond to different continental blocks, the southern Iberian paleomargin and the Alboran block respectively, juxtaposed along the complex, ENE-WSWtrending wrench corridor, the North Betic Wrench fault (Fig. 2A).

The External Zone includes the following domains: 1. the Prebetic autochthonous folded domain, linked northwards to the Meseta; and 2. the Subbetic allochthonous units overthrusting the Prebetic northwards.

The Prebetic and Subbetic are composed of sedimentary series ranging from Triassic to Miocene in age. The Late Triassic evaporites acted as a major level of detachment and have played an important part in the tectono-sedimentary development.

The Internal Zone is composed of numerous allochthonous units: the Flysch, the Dorsal unit, and a pile of nappes of sedimentary and varied metamorphic rocks, mainly altered Palaeozoic and Triassic rocks (e.g. from the base to the top, the Nevado-Filabrides, Alpujarrides and Malaguides nappes).

Neogene successions are widely involved in the polyphase structures of the different domains; they display a great diversity of facies and deformation. It must be emphasised that the Betic orogen was deformed to a major extent during Miocene times, when large areas of various Betic domains were still drowned by the sea, often producing deep marine environments.