Buried Paleoanthrosols of the Bronze Age agricultural terraces in the Kislovodsk basin (Northern Caucasus, Russia)

The article is devoted to the impact of ancient agriculture on soils and landscapes of the Kislovodsk basin. On the basis of pedological and archaeological investigations, we found that the population of the Koban culture (1200-600 BC) of the Kislovodsk basin had a highly-developed agriculture. By the middle of the first millennium BC, more than 60-70% (over 120 km2) of the slope areas and interfluve plateaus at the heights between 900 and 1500 m a.s.l. was terraced. The strongest anthropogenic transformation of soils and landscapes in the region coincided with drastic changes in climatic conditions at the turn of Subboreal to Subatlantic periods. As a result of increasing precipitation and cooling in the middle of the first millennium BC, erosion processes became generally more active. In the region of our study, they were especially strong in consequence of the absence of meadow vegetation. However, the widespread distribution of terraces with horizontal surfaces prevented the formation of ravines on the slopes. The soil and upper part of bedrock washed from the slope of the upper terraces was deposited on the surface of the underlying terrace. As a result, the Bronze Age anthrosols of the terraces were covered by thick layers of slope sediments. The middle of the first millennium BC may be considered as a zero-point of the current stage of soil formation in the Kislovodsk basin. The subsequent warming combined with a decrease of precipitation at the second half of the first millennium BC caused the stabilization of sedimentation and the beginning of the current stage of soil formation in the region.