Astronomically and tectonically linked variations in gamma-ray intensity in Late Miocene hemipelagic successions of the Eastern Mediterranean Basin

Amplitude variations of a 3 My gamma-ray record of Late Miocene hemipelagic successions on Gavdos (Crete, Greece) show remarkable correlation with the amplitude variations of the theoretical insolation curve of Laskar et al. (1993) [Astron. Astrophys. 270, 522-533], with peaks for precession, 100 ka and 400 ka eccentricity cycles. Overall increases in gamma-ray intensities around 8.3 Ma, 7.9 and from 7.16 Ma till the end of our record coincide wi th tectonic events that can be related to the convergence of the African an d the Eurasian plates. These events may have caused important changes in wa ter circulation related to the progressive closure of the seaways between t he Mediterranean Basin and the Atlantic Ocean. (C) 1999 Elsevier Science B. V. All rights reserved.