A. Ruiz Bustos

New data on the upper Miocene micromammals of the Betic Cordillera and their interest for marine-continental correlations

In this paper, we study a new micromammal site called Racor which is located in the Neogene Huercal-Overa basin installed on the Internal Zones of the Betic Cordillera (SE Spain). The presence of Progonomys cf. woelferi Bachmayer & Wilson, 1980 and Rotundomys montisrotundi (Schaub, 1944) characterise the latest Vallesian (near to the Vallesian-Turolian boundary, MN10-MN11 Zones of Mein 1975, 1990). On the other hand, in the Huercal-Overa basin and the Almanzora corridor (in the north of the Almeria province), the stratigraphic position of the Racor site and the first appearance biohorizon of Neogloboquadrina humerosa (Takayanagi & Saito), which marks the Early Tortonian-Late Tortonian boundary, according to biostratigraphic scale of Serrano (1979, 1992), are both located towards the upper part of the Tortonian I unit. We may therefore suppose that both chronostratigraphical limits must be close in time.

Aproximación a la correlación marino-continental del Plioceno inferior en el Sur de España. El yacimiento de micromamíferos de Alhaurín el Grande-1 (Cuenca de Málaga, Cordillera Bética, España)

A new micromammal site at Alhaurin el Grande (Malaga, southern Spain) located above early Pliocene marine deposits allows an approach to the marine-continental correlation for this age. The early Pliocene marine filling throughout the Malaga Basin is developed in three transgressive-regressive sequences (Pl-1, Pl-2, and Pl-3 units) bounded by discontinuities. At the top of the intermediate sequence Pl-2, peaty sediments have yielded fossils of Rodentia, Lagomorpha, Insectivora, and Crocodylia. The presence of Cricetus barrieri Mein & Michaux, 1970 in combination with murids, both of primitive morphology, such as Apodemus gudrunae Van de Weerd, 1976, and more advanced forms (i.e. Occitanomys brailloni Michaux, 1969 and Stephanomys donnezani cordii Ruiz Bustos, 1986), points to an early Ruscinian age (MN 14 biozone). Based on the planktonic foraminifers, the biostratigraphic data indicate that marine sediments just below the micromammal beds belong to the MPl-2 biozone of the early Zanclean. Available paleomagnetic data from the marine sediments show that the micromammal bed must be located between the normal geomagnetic subchron C3n3n (4.89-4.80 Ma) and the subchron C3n2n (4.63-4.49 Ma), limiting the age of this site to the late part of the early Zanclean.