Detalization of the Pliocene - Quaternary North Pacific Diatom Zonal Scale

A high-resolution diatom zonal scale has been developed under the stratigraphic diatom distribution in the Pliocene and Quaternary North Pacific deposits. The levels of the first evolutionary appearance or extinction of some diatom species are the basis in establishing zonal boundaries. Proposed diatom zones are tracked in different facies of the North Pacific, mainly in subarctic latitudes. The analysis of the diatom appearance and disappearance at the boundaries in the deposits of different biogeographic zones shows a space-temporal shift of these boundaries forced by the rates in changes of paleo-populations densities and distribution areas during the expansion and degradation. This specification should be taken into account to provide the correlation between different biogeographic regions with specific features of surface water masses.