X-ray mineralogy studies, ( DSDP) Leg 48 - Rockall region (Sites 403, 404, 405 and 406).

Abstract

3 entirely contrasting mineralogical assemblages are found in succession in the 4 sites. An appreciable change in ocean circulation occurred after the M.Eocene or within the Miocene. As a result, the pattern of sedimentation which was previously dependent on local peculiarities assumes a uniform pelagic character over the entire zone under study. Subsequently, sedimentation is of the modern N.Atlantic type and denotes both a marked cooling in the climate and the development of deep-sea currents from the north. -Keith Clayton