Geological significance of coccoliths in fine-grained carbonate bands of postglacial Black Sea sediments

The origin of fine carbonate muds in deep parts of the Black Sea has been explained in various ways, but details of how the carbonate was formed are poorly understood. We have studied samples containing fine carbonate from cores obtained during the cruise of Atlantis II (Woods Hole Oceanographic Institute) to the Black Sea in April and May 1969. Examination of the light-coloured bands and darker bands by scanning electron micrographs and light microscopy shows that Holocene coccoliths are the overwhelmingly dominant constituents in the light bands, whereas Cretaceous and Eocene coccoliths are important components of the carbonate in the darker matrix.