Caracterización sedimentológica del depósito arenoso de Zabaletxe en la paleorasa emergida de Barrika (Bizkaia, España)

Abstract

This work describes the sandy deposit of Zabaletxe that fossilized the uplifted tidal terrace of Barrika (Bizkaia). The sedimentological, mineralogical, morphological and lithologic parameters of the sandy deposit have been compared with actual sand dunes and beaches. The obtained results suggest that the sand was coming of the abrasion platform during periods of low sea level (what could involve a cold and arid climatic period) and deposited by aeolic processes (dune). About the possible age of formation of the Zabaletxe sandy deposit, this is pre-Holocene (compared with Gorliz dunes) and it may be coeval with the last glacial maximum, or with other events of low sea level, given that the rasa of Barrika may have been subaerial for 300 ka., by its possible correlation with the elevation of Pindal rasa (+60 m), or since 1 Ma by correlation with the rasa of the Asturian coast. The sediment has diagenetic modifications related by lixiviation processes, suggesting a post-depositional warm and humid environment.