PALEOECOLOGICAL NANNOPLANKTON GROUPS IN THE PALEOGENE OF THE ATLANTICAND INDIAN OCEANS

Data from the DSDP and ODP reports were used for the analysis of nanno plankton species presence, distribution and abundance. The summarized meridional profiles were costructed. On this basis the nannoplankton s pecies were grouped in five principal paleoecological groups. Their di stributions reflect the ecological conditions of various biogeographic al zones. These groups are follows: 1) Equatorial-tropical species whi ch do not form marked concentrations. 2) Narros-tropical species which form or do not form high concentrations. 3) The species of broad geog raphical distribution with increase in concentrations in tropical zone s. 4) Subtropical species of general and bipolar distributions. 5) The species of cold subtropic and temperate areas with high concentration s in high latitudes or without high concentrations (bipolar and subpol ar species).