Las diatomeas de los sedimentos del Mioceno medio del borde septentrional de la Cuenca de Guadix

Abstract

Diatoms from Middle Miocene sediments located in the northeast part of the Guadix Basin are here studied for the first time, and the relationship with those from the Guadalquivir Basin established. The results of this study have allowed: a) the sediments to be ascribed to the upper part of the Coscinociscus lewisianus Zone (Barron's 7 985 zonation) which correlate with the uppermost part of the Lower Episode defined in the Guadalquivir Basin; b) the similar diatom content existing in the Guadalquivir Basin and the Guadix Basin at that time, which was indicative of offshore weak upwelling conditions, to be corroborated c) the absence of diatom bearing sediments adscribed to the CD3Q0QdiscuS-giga$_ var. diorama Zone to be verified; possibly in response to an important uplift and a significant eustatic lowering, affecting the Nonhbetic Strait at that time