ЭТАПЫ ФОРМИРОВАНИЯ ПЕРВОЙ НАДПОЙМЕННОЙ ТЕРРАСЫ р. ХОЙТО-АГА (ЗАБАЙКАЛЬСКИЙ КРАЙ) В РАЙОНЕ АРХЕОЛОГИЧЕСКОГО ПАМЯТНИКА ВЕРХНЕГО ПАЛЕОЛИТА САХЮРТА–1

Abstract

Investigation of the 8–10 m high river terrace structure and composition was completed at the archaeological site in the lower Khoito-Aga river. Absolute age of the terrace was estimated using radiocarbon dates of alluvium and buried soils. The results were compared with regional studies of low terraces in the Zabaikalie. The terrace deposits formation stages during the second half of Late Pleistocene and Holocene were identified. The covering genetic complex sediments (2 m) include the Hobdori draw colluvial fan deposits, aeolian, aeolian– deluvial sands and sandy loams, soils. The Сhernozem soil (0.2 m) is recorded in the excavation top. According to archaeological data, it formed during the last ~4.5 kyr. At depths of 100–200 cm, an Early MIS 2 pedocomplex with two humic soil horizons (were dated ~23.4–21.3 kyr BP) was excavated. Soils formed during warm and moist climate stages when rates of exogenous processes were decreased. The completion of alluvium accumulation and terrace escarpment formation were dated ~30–29 kyr BP (MIS 3 and 2 boundary). Interlayed fine–grained and different–grained sands with grus, rubble, gravel alluvial (1.5 m) sediments separated by Late MIS 3 cultural horizons (0.15–0.25 m) with an age of ~ 32.5–31.7 kyr. Within archaeological site Sakhyurta–1 five cultural horizons (CH) were identified with 494 artifacts in total. The cultural horizons 1 and 2 associated with modern soil. The collection of artifacts corresponds to the archaeological sites of the Late Neolithic–Bronze age for Transbaikalia area (4.5–2 kyr BP). Cultural horizon 3 corresponds to the Early MIS 2 pedocomplex (23.4–21.3). СH 4 correlates with terrace alluvium top (31.7–30). СH 5 is associated with alluvial buried soil was dated ~32.5–31.7 kyr BP.