Cross-spectral analysis of two late Berriasian rhythmic limestone-marl successions in SE Spain and SE France favours orbital control

Abstract

The cyclicities in rhythmic limestone-marl alternations of two late Berriasian (hemi) pelagic successions are correlated. The first succession has a thickness of 42.8 m, and is situated in the northernmost Subbetic realm near Caravaca (SE Spain). It comprises the Calpionellopsis simplex subzone (D1). The second succession, with a thickness of 40.5 m, is located about 950 km to the northeast in the Fosse vocontienne near La Faurie (SE France). It starts 2 to 5 m above the base of subzone D1 and ends near its top. The carbonate contents of 740 samples of both successions were used to establish a visual correlation. A more refined correlation was established by cross-spectral analysis of the carbonate/clay ratios. Although the two sedimentation realms differ geographically and geologically, the power spectra show a remarkable resemblance at the eccentricity and precession frequencies, which is numerically confirmed by significant coherence at the 80% confidence level. The cyclicities of both, the Caravaca and the La Faurie succession, are, at least in part, orbitally controlled.