Establishing chronology and raw material of beads from the Chikhen Agui rockshelter in the Gobi Altai

This article discusses methods of processing digital data, which can be applied to studying the objects of paleoart. After analyzing pore patterns on presumably ostrich eggshell beads from the Chikhen Agui rockshelter, aimed at identifying the species of the extinct bird, it was concluded that these beads were unlikely to have been made of eggshell. For proving this, 17 beads were microscopically analyzed. Observation results were interpreted using paleontological data. XRF analysis was performed for identifying the chemical composition, but it was impossible to establish specific raw material, although some of the samples looked similar to marl. CT-scanning revealed not a porous structure but inner cracks in the fabric of the beads. Some beads could have been subjected to heat treatment, and two beads showed the remains of red pigment on their surfaces. In terms of size, color, and texture, beads from the Chikhen Agui rockshelter intentionally or unintentionally imitate ornamental patterns on the objects made of ostrich eggshell. The Bayesian analysis divided radiocarbon dates into seven chronological and cultural phases. Currently, only two beads have a firm chronological position between 10,323-8574 cal. BP. Modelled phases revealed two significant gaps in human occupation at Chikhen Agui. The later gap can be easily explained, since it matches the Misox oscillation, but the earlier gap correlates with the warmer Preboreal immediately following the cold Younger Dryas. This phenomenon needs additional study and explanation.