Human occupation of South Eastern Altai highlands (Russia) in the context of environmental changes

Abstract

Multidisciplinary investigations including geomorphological and geoarchaeological approaches, litho-stratigraphic and pedogenetic analysis accompanied by radiocarbon dating show the contrasting human environmental changes within the highlands of the Russian Altai since the late Paleolithic. Radiocarbon ages of fossil soils formed at 1,475–1,730 m a.s.l. indicate draining of the ice-dammed lake in the Kurai basin before the beginning of the Holocene and disintegration of the Chuya lake into several shallow but quite spacious reservoirs by 8,223 ± 181 cal. BP. Using archaeological sites as spatio-temporal markers allows reconstructions to be specified based on geological data. Archaeological site distribution in the Chuya valley between the Chuya and Kurai basins indicates that all cataclysmic flood events related to the Holocene hydrological changes occurred before the Scythian epoch. Due to the redeposition of most Paleolithic finds in the region, they should be carefully examined before they are utilized for any reconstructions. Using fossil and contemporary soils as an independent informative climatic proxy archive supports the conception of generally more humid and warmer climate conditions in the first half of the Holocene within the SE Altai and a more arid and cold climate in the second one. The repeated climate deteriorations that caused glacier expansion and the progressive aridity intensification in the region along with the sociopolitical reasons are the major factors that controlled the habitat of nomadic communities and cultures shifting within the SE Altai in the second half of the Holocene. Anthropogenic impact together with the progressive aridization led to the deforestation of the eastern part of the Chuya depression.