Milankovitch-type periodicity was identified within Lower Cretaceous cyclic sequences from the western Central Atlantic Ocean and the Vocontian Basin (southeast France) through application of the Walsh spectral method to detailed stratigraphic sections. The repetitious bedding in these sequences appears to be the product of cyclic climatic changes controlled by the orbital forcing. Obliquity seems to be the most important and persistent orbital element responsible for cyclic sedimentation, whereas precession is less important Upper Berriasian and Valanginian strata from the Atlantic Ocean contain indications of eccentricity-induced periodicity and of a nonlinear response of the climatic system. Variations in orbitally tuned pelagic sedimentation rates in the Atlantic Ocean correlate with the changes in the character of cycles and with the occurrence of calcareous turbidites; therefore this suite of sedimentary features are responding to evolving paleoceanographic conditions and possible relative sea level fluctuations. The orbitally tuned durations of the Valanginian and Hauterivian stages in the Vocontian Basin are a minimum of 5.9 and 5.3 m.y., respectively. ¿ American Geophysical Union 1993