http://popups.lib.uliege.be/3041-5527/index.php?id=183 The results of petroarcheological research conducted by the authors based on materials sites of Ust-Menza I and II in the Western Transbaikalia are presented in the given work. A full analysis of these sites’ collections was made and proved that artifacts on jasper, chalcedony and flint (in total, 69%) dominate in the levels of Ust-Menza I site. Similar to the Ust-Menza I raw material data of flint, jasper and chalcedony also prevail (all together 59 %) among the Ust-Menza II artifacts. To find out the source of these high quality raw materials the data on the distribution of these rocks in the region were used. As a result, it was found out that the sources of raw materials were removed from the Ust-Menza sites at a minimum distance of 150 km. in a straight line. Thus, we believe that the absence of vitally necessary minerals and rocks in the significant part of the territory of Western Trans-Baikal region forced Paleolithic humans to move permanently in order to replenish stocks of these raw materials. Numéros en texte intégral ERAUL 140 Thème I : Asie fr Wed, 20 Nov 2024 15:09:06 +0100 Wed, 20 Nov 2024 15:09:15 +0100 http://popups.lib.uliege.be/3041-5527/index.php?id=183 0