Material composition of Pleistocene deposits in the south chamber of Denisova Cave: first results of comparative analysis

Geochemical and mineralogical markers of the materials from geogenic, biogenic, and anthropogenic sources were identified in layers 18 and 13 sampled at various locations in the southern chamber of Denisova Cave. The validity of these markers for comparison and correlation of the layers from different parts of sedimentary sequences, including those from disturbed areas, was established. Archaeological artefacts indicate that during the formation of these layers, in MIS 7 and at the end of MIS 5, respectively, the cave was regularly used by humans. The composition of layers 18 and 13 is examined and compared with that of layers 19.2 and 19.1, which formed at the boundary ofMIS 9-8 and are composed entirely or predominantly of geogenic material. For the first time, contributions of geogenic, biogenic, and anthropogenic materials to the bulk phase and the chemical composition of layers 19.2, 19.1, 18, and 13 were assessed. The applicability ofphase (mineral) and macro-component characteristics of bulk sediments, as well as their individual components as markers for each source of material was proved. It was found that, at the base of the section, sediments consist entirely (layer 19.2) or predominantly (layer 19.1) of the residual aluminosilicate material, commonly referred to as the cave terra rosa. In layer 18, the amounts of the aluminosilicate rock material (both intra-cave and external) and the phosphate material (primarily bone) are comparable. The biogenic component in this layer is mainly associated with animal bones and coprolites. Ash calcite was discovered in this layer for the first time, suggesting fire human activity inside the cave. Mineralogical and geochemical characteristics of layer 13 indicate that the contribution of the biogenic material to its bulk composition exceeds that of the geogenic sources. Along with stone artifacts and broken bones, numerous fragments of microcharcoal and ash calcite reveal remarkable anthropogenic contribution to these sediments.