EUSTATIC SEA-LEVEL AND CLIMATE CHANGES OVER THE LAST 600 KA AS DERIVED FROM MOLLUSC-BASED ESR-CHRONOSTRATIGRAPHY AND POLLEN EVIDENCE IN NORTHERN EURASIA

Abstract

We reconstruct and correlate palaeoclimatic events and deposits from shelf, glacial, periglacial, and extraglacial zones of northern Eurasia over the last 600,000 years. The chronostratigraphical correlation of identified palaeoenvironmental and sea-level events and corresponding horizons is based on electron spin resonance (ESR) analysis of subfossil mollusc skeletal remains from marine, freshwater and Acheulian-bearing cave-site deposits. Over 230 shell samples from more than 40 sites along the continental margin of Eurasian north, in the Black and Caspian sea basins and terrestrial shells from a Lower Palaeolithic cave-site in the Northern Caucasus were dated via ESR to produce a late Quaternary geochronology. The Pleistocene composite section of the loess-palaeosoil formation includes two reference sections—Likhvin and Arapovichi—from the centre of the East-European plain. The palyno-chronostratigraphic record is interpreted as the product of six warm-climate/high sea-level events including the current interglacial, and six glacial events. They are presented either as complete climatic rhythms of glacial and interglacial rank, or by considerable portions of climatic–phytocoenotic phases constituents of the rhythm. The full-interglacial conditions are centred at about 580, 400, 310, 220 and between 145–70 calendar ka. A broad correspondence between long palynological sequence, directly ESR-dated warm-climate-related events and other palaeoenvironmental records described in the literature has been noted for 11 upper oxygen isotope stages (11 to 1). The results obtained in this study exemplify the potential of integrated chrono-climatostratigraphic sequences in linking marine and terrestrial palaeoclimate records that may eventually span the whole Brunhes chron.