CONSIDERATIONS ON THE EMERGENCE OF TIRRENIENSIS LAYERS DETECTED BETWEEN CABO ROIG (ALICANTE) AND THE MONTH OF THE ALMANZORA RIVER (ALMERÍA)

Abstract

The purpose of this geornorphological study, which considers both glacio-eustasy and neotectonics, is to define the conditions under which deposition took place of those coastal landforrns characterized by a last-interglacial, warm Quaternary marine fauna. Consideration of coastal outcrops between Cabo Roig (Alicante Province) and the mouth of the R. Almanzora (Almería Province), leads to the conclusion that they correspond to a shoreline of a marine environment characterized by Sirombus buhonius, in the beaches and spits of which continental materials are scarce. The spits which closed off coastal lagoons manifest characteristics typical of those beside an open sea, while the fossil beaches could belong either to the transgressive hernicycle (the older ones) or to that of the subsequent regression within the transgressive cycle. The observations should be regarded in the context of the geodynamic record of this area of the Mediterranean, and it is hoped that they may conform to data from the Moroccan shore of the Straits of Gibraltar. They underline the prevalent influence of neotectonic activity and should alert us to the inherent risk in wrongly assuming that each and every fossil beach deposit of the pre-Würmian shore corresponds to a separate high stand of sea level merely because they lie at somewhat different heights above sea level. The scheme presented here attempts to offer some clarification. taking into account the geomorphological data, such that it may serve as a starting-point for defining the evolution and tendencies of those coastal areas where morphogenesis is fundamentally controlled by alterations in base-level.