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The soils of Russian Altai highlands were used as a paleoenvironmental archive, as a source of dating material, and as a chronostratigraphic marker to describe Holocene environmental change in the studied area. Based on calibration intervals of 14C dates obtained for buried humus horizons (11 buried soils in 6 studied soil-sedimentary sequences) and some dates from pendants of contemporary soils, following stages of pedogenesis were recorded in studied soil-sedimentary systems and surface soils: 6.4 – 11.5 ky cal BP; about 4.9-5.3 cal BP; 2.5-3.8 cal BP; 0.6 – 1.2 cal BP. All studied surface soils in the basins nowadays develop in cold, ultra-continental water deficit conditions: Skeletic Kastanozems Cambic, Skeletic Cambisols Protocalcic, Skeletic Cambic Calcisol Yermic. The most extreme conditions of soil formation within Holocene were within the last 1-2 kyr. All buried soils were formed in better conditions, more balanced in water, with higher biological activity, mostly within steppe or forest-steppe landscapes. Cryogenic features had been insisting all over the Holocene till nowadays. Water demandant cryogenic features are met in buried soils up to the age of 1-2 ky cal BP. In the last millennia cryogenic processes are suppressed, water demandant features gave way to those which can be formed in contemporary water deficit conditions: simple fissures, frost sorting, and shattering. At lower levels (Kuraj basin) more or less arid cold steppe conditions insisted within the most part of Holocene. Initial stages of soil formation were often ground water affected, or at least shortly waterlogged. At the highest positions humid and relatively warm Early Holocene stage of forest pedogenesis is recorded for the beginning of Holocene, and a Late Holocene (last 3-4 kyr) cold humid phase, presumably under mountain tundra and/or alpines. Microsedimentary intra-soil record in carbonatehumus pendants imprints fine fluctuations of soil water regime at initial stages of soil formation, controlled by local topography, and climatic changes in the second half of Holocene. General trends of environmental changes in the region recorded in soil and soil sedimentary systems are in well correspondence with other records of paleonvironment.

The geomorphological studies and radiocarbon dating of moraine complexes and the tree line within the North Chuya Ridge, along with active slope processes, soil formation, and peat formation in southeastern Gorny Altai, constrain the age of the main glacial and climatic events in this area at 7 ka to the first half of the 19th century. It is for the first time in the history of Altai studies that 57 absolute dates were obtained for glaciation in a vast but climatically and neotectonically homogeneous area. The new data refute the conventional idea that the Holocene glaciation in this mountain land comprised eight stages of the gradual retreat of the Late Würm (Sartan) glaciation. Also, they evidence that glaciation in the upper parts of the troughs retreated almost completely no later than 7 ka and valley glaciers in southeastern Altai were activated many times in the second half of the Holocene. Data are given on the morphology and age of three moraine generations reflected in the topography. A combination of temperature minima and humidity maxima led to a catastrophically rapid and the largest (up to 5–6 km) ice advance at the Akkem Stage (4.9–4.2 ka). In addition to the radiocarbon data, the time limits of the Historical stage (2.3–1.7 ka) were defined more precisely using dendrochronological and archaeological data from Scythian burials of Pazyryk culture in SE Altai. The moraines closest to the present-day glaciers formed at the Aktru Stage (late 13th–middle 19th century). During warm interglacials, the glaciers waned considerably or retreated completely and the zone of recent glaciation was reforested. As a result of progressive aridization in the Holocene, the glaciers in southeastern Altai waned at each successive stage, and their mass balance was not positive during the greatest temperature minimum of the last millennium (middle 19th century).

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We present the first results of application of long-term tree-ring chronologies for dating seismically triggered rockfalls and determining the upper age of Holocene rockfalls in southeastern Altai. Based on the results of seismic dendrochronological analysis, dating of penetrating wood injuries is proposed and tested, and the criterion for the distinguishing of seismically triggered rockfalls among slope processes of climatic nature is formulated. An earlier unknown strong earthquake of 1532 has been recognized; its traces are dated by the radiocarbon method. Based on the new data and calibration of earlier radiocarbon dates, the recurrence period of strong earthquakes in the southeastern Altai is refined.

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