Pleistocene climate change, natural environments and palaeolithic occupation of the Angara–Baikal area, east Central Siberia

Abstract

Palaeogeographical and palaeoenvironmental evolution throughout the Baikal territory during the Quaternary Period is characterized by the interaction of past global climatic changes and the regional topographic alteration by the neotectonic activity of the Mongolian–Siberian mountain zone. The specific geomorphological character of the Baikal topography governed by sub-rifting orogenic regimes gave rise to a variety of natural settings and landscapes throughout the Pleistocene. An increased accumulation rare of sub-aerial sediments, a broader genetic variety of palaeosol horizons and periglacial surface deformations attest to a progressing climatic continentality during the Late Quaternary. Marked climatic shifts characterize the last glacial–interglacial cycle, with the major glaciations in the East Siberian mountains during the cold (OIS 4 and 2) stages. The mid-last glacial (OIS 3) climatic optimum (dated to 31 ka BP) was thermally approaching the last interglacial (OIS 5e) conditions. Palynological and palaeontological, as well as early cultural data, provide evidence of strongly fluctuating Late Pleistocene climatic variations. Diversity of the palaeolithic records attest to several stages of early human occupation, with the earliest (late Middle Pleistocene) represented by pebble tool industries. Contextual association of the Middle Pleistocene artefacts of the Levallois tradition with the early Last Glacial aeolian sands implies cultural adaptation to cold periglacial environments. Systematic multidisciplinary investigations at chronologically and contextually well-fixed palaeolithic sites provide additional multi-proxy information on the Pleistocene climate change and the dominant geomorphic processes over the particular geographic area. Reconstruction of the evolutionary pathways and processes in the natural environments, the specific material-technological conditions and the production level of the early human communities, as well as documentation of climatic events stored in the geological record are the principal study objectives of the current geoarchaeological studies in the Baikal sector of Siberia.