Raw materials of the early middle Paleolithic industries from Denisova cave

Based on the petrographic analysis of artifacts, the article characterizes the lithic raw materials of the Early Middle Paleolithic industries from Denisova Cave. For the study, a sample of objects with secondary treatment was taken from layers 14 and 15 in the East Chamber of the cave and layers 17 and 18 in its South Chamber. After studying physical properties under a binocular magnifying glass, the rocks were determined in thin sections. The X-ray phase analysis and scanning electron microscopy were also used. According to the petrographic composition, 88 % of the used raw materials are represented by sedimentary rocks, primarily quartz and feldspar-quartz fine-grained sandstones, silty sandstones, and siltstones. Several artefacts show weak contact alterations of these rocks detected only by microscopy in petrographic thin sections. Volcanic rocks are aphyric and porphyritic. The fine-grained rocks and their predominantly massive texture made it possible to split in different directions, which increased material versatility for making tools. It has been established that Silurian sedimentary rocks of the Chineta and Polatinskaya formations in the upper reaches of the Karakol River served as a source of raw materials, where they are intruded by the Bashchelak mass of Devonian granitoids. This is confirmed by the presence of products from hornfelsed sedimentary rocks, as well as the predominance of gray and dark gray siltstones and silty sandstones among them, which are typical only for the deposits of the Chineta and Polatinskaya formations. The study has shown that the most ancient inhabitants of the Denisova Cave were well acquainted with petrophysical properties ofpebble raw materials from the channel alluvium of the Anui River and its tributaries. The most homogeneous pebbles were selected with a hardness of 5-6.5 according to the Mohs hardness scale.