LATE PLEISTOCENE-HOLOCENE BENTHIC FORAMINIFERS AND EVOLUTION OF NEAR-BOTTOM ENVIRONMENTS IN THE CENTRAL SEA OF OKHOTSK

Abstract

Taxonomic composition and distribution of benthic foraminifers in the upper Pleistocene-Holocene sediments that are penetrated by the gravity core in the southern slope of the Akademii Nauk Rise in the central part of the Sea of Okhotsk (Station V34-90) are discussed. Four established assemblages of benthic foraminifers successively replacing each other upward in the section reflect relevant stages of hydrological evolution of the basin: the terminal stage of the last glacial (2000-12500 years ago), deglaciation stage (12500-8500 years ago), and the early (8500-4000 years ago) and late (the last 4000 years) phases of the current interglacial. A comparison between foraminiferal assemblages from the Akademii Nauk Rise and from coeval sediments studied before in the southeastern part of the Sea of Okhotsk revealed that the near-bottom environments during both the deglaciation and current interglacial periods differed in these areas. It is assumed that these regional differences point to the time-variable influence of the Pacific warm water.