Introduction

The transition from the late Neogene to the Pleistocene in the Iberian Peninsula was characterized by widespread erosion on the Meseta and its margins because of structural deformation associated with subsidence over wide areas, both along the Mediterranean shorelands and in the intramontane basins along the Betic front. Marine deposition was rare and was restricted to littoral fringes. Volcanic activity in the southeast, and also in the southern Meseta, decreased after the end of the Miocene. The paleomagnetic record is extremely limited. However, there are significant sites in continental environments with both small and large vertebrates (Figure 13.1) that provide the material for interregional correlations.

Stratigraphic sequences

Bay of Cádiz

The Bay of Cádiz, in the area between the Guadalquivir depression and the western margin of the Subbetic realm, was first inundated during the late Miocene Tortonian transgression. The subsidence of the bay was related to the advance of the Subbetic olistostrome to the north-northwest, and its present configuration was influenced by a normal fault along an east-northeast axis.

Torre del Puerco section. This section (36°19′20″N; 2°29′45″W) begins with marls and marly limestones of the TP-1 (Torre Puerco Unit 1) containing Globorotalia margaritae, overlain by TP-2 marly sands and bioturbated offshore horizons with G. crassaformis. Near its top, G. margaritae, G. crassaformis, and Turborotalia puncticulata disappear, but Globigerinoides extremus and Turborotalia humerosa are still present. The TP-3 shallow conglomerates that close this cycle yield abundant rhodoliths of Lithotamniaeae, with Flabellipecten planomedius, Pseudoamussium calcatur, Pecten jacobaeus, and Ostrea lamellosa. The top of the series is continentally karstified, and it disconformably underlies a lower to early middle Pleistocene terrace with Olduwan-like pebble tools.