PERIODICITY OF MAGNETIC INTENSITIES IN MAGNETIC ANOMALY PROFILES - THE CENOZOIC OF THE SOUTH-ATLANTIC

Spectral analyses of several published magnetic anomaly profiles from Cande & Kent (1992a) were undertaken prior to analysing, in the same w ay, raw magnetic anomaly data from similar parts of the South Atlantic . It was found that similar and distinct medium and short wavelengths were present in both the published and raw data. When these are conver ted into the time domain using the average rate of spreading for each profile, these periodicities appear similar, possibly identical, to th ose expected from the long-term eccentricity orbital parameters (Fisch er, DeBoer & Premoli Silva 1990). While such correlations are not nece ssarily causative, they suggest that magnetohydrodynamical processes n ear the core-mantle boundary may be affected by gravitational changes due to planetary orbital perturbations.