The effect of formation processes on Palaeolithic settlement patterns: insights from south Kazakhstan and the Swabian Jura, southern Germany

Abstract

Understanding the factors that control the distribution of Palaeolithic sites comprises a fundamental objective of archaeological science. Geoarchaeological approaches focusing on site formation processes have been widely applied to demonstrate the factors that influence the formation and preservation of Palaeolithic sites over time. However, available knowledge is heavily skewed towards extensively researched parts of the world and focuses primarily on the site-specific analyses of landmark Palaeolithic sites. In this context, no previous study used a systematic geoarchaeological approach to investigate the impact of formation processes on a regional level in Central Asia, despite the critical role of Central Asia in hominin evolution and dispersals. Furthermore, as the formation history of low-density archaeological sites remains unaddressed, the role of low-density sites in hominin hunter-gatherer settlement patterns remains elusive, even for regions with a rich Palaeolithic record. On this basis, this PhD thesis performed a multi-scalar approach to the analysis of the interplay between formation processes and settlement patterns, by investigating site distribution on a regional scale in Kazakhstan, Central Asia, and a local scale in the Swabian Jura, Germany, Europe. Paper I, “In search of a Palaeolithic Silk Road in Kazakhstan”, provides a geoarchaeological framework for contextualizing a field survey in the Inner Asian Mountain Corridor (IAMC) of Kazakhstan. The field survey explores the distribution of Palaeolithic sites in a crucial region for Late Pleistocene hominin evolution, testing the fundamental assumptions that govern predictive models of hominin dispersals and behavior in Central Asia. The results revealed that three geomorphic settings, karst, loess, and spring deposits, are the most promising for the formation and preservation of archaeological sites. A detailed discussion explores the systematic biases that influence data collection and interpretation, according to the type of geomorphic context in which the sites are recovered. In the framework of this systematic geoarchaeological analysis, a primary aim was to investigate the formation processes that influence the formation and preservation of Pleistocene deposits in the most promising geomorphic settings in Kazakhstan, the caves and rockshelters of the Qaratau mountains (Paper II). Paper II, “The effect of formation processes on the frequency of Palaeolithic cave sites in Semi-Arid Zones: Insights from Kazakhstan”, combines site-specific data, extracted from the micromorphological analysis of selected caves, and landscape data, extracted from survey observations, to not only interpret but also assess the completeness of the known regional archaeological record. In this way, it sets a novel basis for investigating the formation and preservation of cave deposits in Kazakhstan, with broader implications for the distribution of Palaeolithic cave sites in Central Asia. The results demonstrated that cave formation processes are tied to regional geomorphic and climatic factors, with implications for caves in similar semi-arid settings. Pleistocene deposits are scarce, while aeolian loess-like cave sediments and reworking processes of varying intensity dominate the depositional sequences. Furthermore, hillslope erosion and loess cover impact the long-term preservation of caves in the landscape. Given the regional scarcity of Pleistocene archaeology in the caves of Kazakhstan, emphasis was given in exploring the formation processes of low-density cave sites and their role in settlement patterns in a more local scale (Paper III). Paper III, “Low density occupation sites from the Swabian Jura: Implications for site formation processes and settlement patterns”, applies a site-specific approach based on micromorphological analysis, to explore the formation history of selected low-density and anthropogenically sterile cave sites located in the Swabian Jura, Germany, one of Europe’s richest regions in terms of Late Pleistocene Palaeolithic assemblages. The results showed that low-density cave sites are dominated by phosphatic features associated with carnivores, demonstrating the use of cave spaces by both predators and hominins. Most importantly, the absence of dense archaeological horizons is not attributed to intense geogenic processes, but rather to hominin intentionality. In this regard, the low-density cave sites reflect sporadic hominin use, most probably associated with specific mobility strategies. Overall, this PhD thesis identified a clear association between formation processes and the distribution of archaeological sites based on both site-specific and landscape-specific analyses. The regional scale geoarchaeological analysis in Kazakhstan demonstrated that in-built biases characterize the archaeological record in different geomorphic contexts, while geogenic processes triggered by the semi-arid environment may explain the removal of caves from the landscape leading to a low-density distribution of archaeological cave sites. At the same time, the local scale geoarchaeological analysis in the Swabian Jura demonstrated that hominin intentionality and not geogenic processes control the formation of a sporadic low- density archaeological cave record. By understanding the processes that shape the distribution of archaeological sites or the formation of low-density sequences over a given area, we are able to assess the completeness of the archaeological record and construct more accurate interpretations regarding hominin dispersals and settlement patterns.