People and Volcanoes of the Okа Plateau in Ancient Times: the Infl uence of Volcanic Activity on the Choice of Settlement Sites

The Oka Plateau is situated in the Sayan Mountain System on the West of the Buriatia Republic. In the Late Pleistocene, this territory was influenced by local glaciers which were developed along the rivers’ valleys. . Glaciers played an important role in the strategy of human development of the territory of the Oka Plateau, for long periods of time making inaccessible the numerous valleys of the tributaries of the Oka River, the main water artery of the Oka Plateau. Starting from the end of the Pleistocene and throughout most of the Holocene, volcanic activity intensified in the upper reaches of the Zhobolok (a tributary of the Oka). The poured lava flows advanced into the Oka valley and blocked the river, creating a natural dam. As a result, a vast dammed paleolake was formed above the dam. After the natural situation stabilized, the shores of the paleolake were actively developed during the Holocene optimum. It was the settlement of the people whose material culture finds many analogies among the archaeological materials of the Angara region. In 2021, a series of Neolithic sites were discovered in the area of Zun Nomto-Gol. During the study of these sites, the frequency and sequence of development of the shores of the ancient lake were established. The fact of a gradual decrease in the level of the dammed lake at an early stage of its existence (the Neolithic era according to archaeological periodization) has also been established. Later, the water level in the lake decreased dramatically and many ancient sites turned out to be high above the water, which led to the cessation of the development of previously inhabited areas.