The Nature-Determined Character of the Early Arable Farming in Northwest and Inner Mongolia

The materials presented in this paper are a continuation of studies on the early arable farming in Mongolia. Traces of multiple ancient agro-irrigation landscapes in Northwest Mongolia (Ubs Nuur Basin and western spurs of the Khangai) were discovered, as well as the associated settlements. The geological position of this territory, orogenic processes, and neotectonic shifts factored into the formation along the young rising mountain ranges of subaerial deltas favorable for the development of sai arable farming dated to an early stage of ancient irrigation. Initially, embanked channels of short-term streams of the subaerial deltas were transformed into rather extensive irrigated territories. In addition to the traditionally irrigated landscapes (subaerial deltas, deluvial–proluvial slopes, and floodplains), the field boundaries tended to peatlands and peat-containing soils formed in the basin of Lake Ubs Nuur, as well as peatlands formed as a result of the damming of Nariin Gol during the uplift of the Agardag Mountains. Since the territory of Mongolia belongs to a region of manifestation of young basaltoid magmatic activity, concentration of the ancient fields in immediate proximity to recent volcanoes (Khorgo (also Horgo), the Tes-Gol field) implies the use of fertile volcanic ash and natural heat in farming practices of the population. The presence of stela with a runic writing system dated to the second half of the 8th to early 9th century suggests the existence of arable farming in Northwest Mongolia during the Uyghur time period.