Dynamics of nival and glacial slope processes in the Baksan and Teberda river basins from radiocarbon dating of buried soils

Abstract

Radiocarbon and tree-ring dating of the soil horizons, buried in the slope and fluvioglacial deposits in Baksan and Teberda valleys, bring evidence of the reduction of the avalanche activity, stabilization of the slopes and soil formation on their surfaces. In the Baksan section three such horizons are identified, while in the Teberda section only one. The radiocarbon dates of the two thickest soil horizons in the Baksan section are 170±50 BP (1650–1890 CE) and 380±60 BP (1430–1650 CE). The dendrochronological date of the wood (after 1677) in the upper layer of the buried soil horizon in the in the Dombai section probably indicate the increase of the river runoff and debris flow activity in relation with the glacier advance in the upperstream of Ammanauz river. However it is also close to the Terskoye earth quake occurred in 1688. The radiocarbon dates of the buried soils cluster in three groups (270–290, 340–440, 1280–1440 yrs BP). It is possible that their burial is connected to the climatic (increase in precipitation, especially extreme ones) or seismic causes.

Keywords

• аvalanches
• buried soils
• dendrochronology
• glacier fluctuations
• radiocarbon dating
• seismic activity
• slope processes