Abstract
A high-resolution analysis of cyclical patterns in gamma-ray and sonic logs of the lower Pliocene sediments from the Gulf of Cadiz (southern Spain) was carried out. Results suggest that these cycles can be successfully used for a bed to bed correlation with the global reference section for the astronomical time scale in Capo Rossello (Sicily). Cycle patterns were used to tune the logs to the astronomical solutions of J. Laskar. The gamma-ray and sonic cyclicity was interpreted in terms of precession-induced oscillations of annual rainfall in southern Spain that were, in part, responsible for the increasing input of freshwater into the Mediterranean at times of sapropel formation. We demonstrate that gamma-ray and sonic astrochronology can be successfully used for interregional correlation and astronomical dating with errors not higher than 20 k.y.