THE LATE HOLOCENE CLIMATE CHANGE EFFECT ON SEDIMENTATION ENVIRONMENTS NEAR THE ANTARCTIC PENINSULA

The paper is devoted to the Late Holocene sedimentary paleoenvironments in the open northern part of the Antarctic Peninsula basin that is particularly sensitive to rapid contemporary climate change. The main goal is to trace the successive environmental transformation of hydrological and climatic conditions which affected the Core K98-08 (floor depth 1227 m) deposits formation recorded in proxy diatom data. On the basis of taxonomic composition and ecological structure of fossil diatom assemblages and horizons' lithology, the Late Quaternary paleoenvironmental conditions were defined. The surface sediments were formed in deep ocean basin under the influence of different-temperature water mixture, this basin being characterized by sea ice cover in winter and surface water's average temperatures of -1 ? +1,5°C in summer. The taxonomic composition of diatom assemblages suggests that the surface sediments were formed at the Late Holocene. The comparison of new data with paleoclimatic records [7, 9-10] indicates that the beginning of core deposit accumulation is broadly synchronous with the Neoglacial interval (?2400 yr BP). According to our rough estimates the average Late Holocene deposition rate was ca. 18-19 cm per 1000 years in the place where the station was located. The present-day rapid warming began about 450-500 yr ago in the Northern Antarctic Peninsula. This study focuses on new data of the Late Holocene sedimentation rate and environments in the north area of the Antarctic Peninsula basin for a climate and paleoceanological reconstructions in the Southern Ocean.