1Department of Land Resource Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
²Centro di Studio per la Geologia dell'Appennino del CNR, Istituto di Geologia, Universita di Firenze, 50121 Florence, Italy ³Kansas Geological Survey, University of Kansas, Lawrence, Kansas 66044, U.S.A

The Antola Formation of Upper Cretaceous age crops out extensively in the Northern Apennines and consists of graded units of calcareous sandstones, sand- stones, marlstones, and shales. It can be subdivided into the Cerreto, Antola Marlstone, Bruggi, and S. Donato Members on the basis of bed thickness and percentage of shales. Although the whole formation is interpreted as a deep-sea basin plain deposit, the members constitute lateral facies subdivisions that range from proximal, thick-bedded turbidities that show a prevalence of thinning upward cycles in bed thickness to distal turbidites that show predominantly thickening upward cycles and have a high percentage of shale.
   Repetitive patterns in the lithological sequence of the turbidite association are generally distinctive and are satisfactorily described as first order Markov chains. Only the Antola Marlstone Member has an additional second order Markov property. Imaginary eigenvalues of the transition probability matrices of all but the Bruggi Member demonstrate a strong cyclic character in the lithologic ordering within the formation. The behavior of the Antola Marlstone and of the Bruggi may reflect the influence of a secondary ophiolitic intra-basinal source of clastics that contributed sandy turbidites and olistostromes.
   Systematic long-term variations in the sequence of bed thickness development in some sections of the Antola Formation are often subtle and equivocal, and pose special problems in interpretation. Fourier analysis was applied to the task of partitioning fundamental wavelengths from 'background noise' introduced by essentially random depositional processes. In all members there is (1) strong short-term wavelength of two to three beds indicative of alternating thin and thick beds and judged to be typical of turbidite sequences; (2) an intermediate wavelength ranging from about five beds (proximal facies), eight beds (distal) to nine beds (very distal), which have both thinning and thickening upward trends, interpreted respectively as valley fill due to shifting thalweg of low density turbidity currents, and to progradational, flat turbidite lobes; (3) a poorly defined long-term wave- length of from thirty to greater than sixty beds that may be related to an unspecified trend in the evolution of the sedimentary basin. Phase angles associated with the computed power spectra give indications as to the asymmetry (thickening or thinning upward) or symmetry of the representative units.