Archaeological Sites as Markers of Hydrosystem Transformation in the Kurai and Chuya Basins, Southeastern Altai, in the Late Pleistocene and Holocene. Summary of Findings and Paleogeographic Reconstructions

Abstract

This paper is the second in a series of publications on various aspects of the relationships between man and environment in the highlands of southeastern Altai. In these studies, we assess the impact of climatic changes (evidenced by processes of glaciation and deglaciation, the emergence of ice-dammed and residual lakes, soil and peat formation, and seismic activity) on the succession of sedentary and nomadic cultures, and on the ranges of their distribution, in the Late Pleistocene and Holocene. Geochronological data on the evolution of Late Pleistocene ice-dammed lakes and Holocene residual lacustrine systems within the Kurai and Chuya intermountain basins, including our new findings based on geomorphological, geoarchaeological, and geochronological approaches, were summarized in the first paper of the series. Using Paleolithic sites for assessing the time in the Late Pleistocene when the Chuya paleolake emptied is unwarranted, because their estimated age limits are wide, many are likely redeposited, and most finds are random. However, analysis of the spatial distribution of in situ sites spanning the period from the Late Bronze Age to the Middle Ages has provided evidence regarding the transformation of Holocene hydrosystems. New radiocarbon dates indicate a substantial decrease of the Sartan glaciation before 14 ka cal BP, and desiccation of the last ice-dammed lakes within the Kurai and Chuya basins before 10 ka cal BP. The absence of Early Holocene archaeological sites in those areas may be due to the wide distribution of residual lakes in the bottoms of those depressions at that time. © 2017 A.R. Agatova, R.K. Nepop, I.Y. Slyusarenko.