The Effect of Formation Processes on The Frequency of Palaeolithic Cave Sites in Semi-Arid Zones: Insights From Kazakhstan

Abstract

Central Asian caves with Palaeolithic deposits are few but they provide a rich record of human fossils and cultural assemblages that has been used to model Late Pleistocene hominin dispersals. However, previous research has not yet systematically evaluated the formation processes that influence the frequency of Palaeolithic cave sites in the region. To address this deficiency, we combined field survey and micromorphological analyses in the piedmont zone of south Kazakhstan. Here we present our preliminary results focusing on selected sites of the Qaratau mountains. Sediment cover varies among the surveyed caves and loess-like sediments dominate the cave sequences. The preservation of cave deposits is influenced by reworking of cave sediments within the caves but also by the broader erosional processes that shape semi-arid landscapes. Ultimately, deposits of potentially Pleistocene age are scarce. Our study provides new data in the geoarchaeologically neglected region of Central Asia and demonstrates that micromorphology has great analytical potential even within the limitations of rigorous survey projects. We outline some of the processes that influence the formation and preservation of cave deposits inKazakhstan, as well as broader implications for the distribution of Palaeolithic cave sites in Central Asia and other semi-arid environments.

Nazugum, a new 4000 year old rockshelter site in the Ili Alatau, Tien Shan

“…Therefore, based on this correlation we can infer about 2 meters of loess deposition in the proximity of the rockshelter for the last 4,500 years. Second, even though aqueous processes have usually minor impact in the formation and reworking of sediments in the semi-arid landscape of Kazakhstan (Varis et al, 2021), we see that in the case of Nazugum rockshelter they play a prominent role in the preservation of the archaeological record through time.…”

“…However, due to the proximity of the cave with the river, we cannot exclude the possibility that both the loess and the artifacts could have been influenced by fluvial action, most probably during flood events. In Kazakhstan, aqueous induced reworking of loess in a cave/rockshelter context has also been reported in the site of Jetiotau (Varis et al, 2021).…”

“…The site of Nazugum has also important implications for the formation and preservation of cave and rockshelter archaeological sites in Kazakhstan. First, the presence of a thick loess deposit that fills the majority of the rockshelter demonstrates the influence of loess-deposition for the build-up of thick archaeological sequences in Kazakhstan, as well as the potential masking of archaeological sites from the landscape (see also discussion in Varis et al, 2021). In the case of Nazugum, the radiocarbon sample located close to the base of the loess unit provides a terminus post-quem for the onset of loess deposition.…”