Periodic Reporting for period 4 - PALAEOSILKROAD (A Silk Road in the Palaeolithic: Reconstructing Late Pleistocene Hominin Dispersals and Adaptations in Central Asia)
Reporting period: 2021-12-01 to 2023-01-31
The Silk Road was an ancient network of trade routes that crossed central Asia, constituting the primary link between the Middle East and East Asia during late antiquity and the early Middle Ages. It is frequently cited as one of the most important and long-lasting conduits for bio-cultural exchange in human history and continues to play a crucial role in Asian geopolitics today. To avoid crossing the deserts and high mountains of arid central Asia, travellers used the more temperate corridors through the mountain foothills (piedmonts). The PALAEOSILKROAD project set out to test the hypothesis that at least some of these corridors were used earlier still, by hunter-gatherers in the Stone Age. The extremity of the most arid phases of the last glacial cycle (the late Pleistocene, 110-11 500 years ago) makes such a strategy likely. Because we know from genomic studies that these dispersals are in large part responsible for the origins and makeup of modern Asian peoples, uncovering their archaeological traces is of utmost importance.
Since all current models of dispersal through the region suffer from the low quality and density of the input data, the PALAEOSILKROAD project aimed to discover new Palaeolithic sites in the foothills of the Qaratau, Tian Shan, Dzhungarian Alatau, and Southern (Kazakh) Altai mountains in Kazakhstan, together known as the Inner Asian Mountain Corridor (IAMC). Our second objective was to use these new data to examine how humans adapted to the climatic fluctuations of the last glacial cycle (ca. 110-11 500 years ago).
To achieve these goals, we combined novel remote-sensing techniques with traditional geomorphically-informed foot-survey to discover and explore 95 unknown caves and rockshelters. A subset of these were selected for excavation, revealing several occupations from ca. 50 to five thousand years ago. Together with the open air sites recorded by the project, we have now increased the data density in the study region fivefold. The new sites offer a continuous record for reconstructing occupation history and matching it to climatic oscillations of the Late Pleistocene. Although our conclusions are still preliminary, we see an emerging role for caves in piedmonts as refuges for people during periods of climatic deterioration, such as the Last Glacial Maximum.
Another important objective of the project was to investigate biases in the archaeological record and their causes. We concluded that, although caves are important biological archives, the conditions for their formation in this semi-arid region might limit the number of possible sites. Tectonic spring sites emerge as an important, yet so far untapped focus for future research. These results will help orient future efforts to discover new archaeological sites and interpret spatial and temporal gaps in the archaeological record of this crucial region.
We also carried out the first studies of the distribution of raw materials used by ancient people in the IMAC to fashion their tools. Given the diversity of rock types in Kazakhstan, we had to develop new and objective methods to study and compare their quality, so that we could understand the choices of material transport made by ancient people. These methods have been adopted for other regions and the data generated will contribute to future models linking dispersal to economic decisions and everyday mobility.
Finally, we modelled the success of dispersal through the corridor as a function of social strategies. The evolutionary agent-based model we produced suggests that a high degree of individual cooperation among the dispersing groups would be required to survive in the harshest climatic conditions of the last glacial cycle in the IMAC.
Since all current models of dispersal through the region suffer from the low quality and density of the input data, the PALAEOSILKROAD project aimed to discover new Palaeolithic sites in the foothills of the Qaratau, Tian Shan, Dzhungarian Alatau, and Southern (Kazakh) Altai mountains in Kazakhstan, together known as the Inner Asian Mountain Corridor (IAMC). Our second objective was to use these new data to examine how humans adapted to the climatic fluctuations of the last glacial cycle (ca. 110-11 500 years ago).
To achieve these goals, we combined novel remote-sensing techniques with traditional geomorphically-informed foot-survey to discover and explore 95 unknown caves and rockshelters. A subset of these were selected for excavation, revealing several occupations from ca. 50 to five thousand years ago. Together with the open air sites recorded by the project, we have now increased the data density in the study region fivefold. The new sites offer a continuous record for reconstructing occupation history and matching it to climatic oscillations of the Late Pleistocene. Although our conclusions are still preliminary, we see an emerging role for caves in piedmonts as refuges for people during periods of climatic deterioration, such as the Last Glacial Maximum.
Another important objective of the project was to investigate biases in the archaeological record and their causes. We concluded that, although caves are important biological archives, the conditions for their formation in this semi-arid region might limit the number of possible sites. Tectonic spring sites emerge as an important, yet so far untapped focus for future research. These results will help orient future efforts to discover new archaeological sites and interpret spatial and temporal gaps in the archaeological record of this crucial region.
We also carried out the first studies of the distribution of raw materials used by ancient people in the IMAC to fashion their tools. Given the diversity of rock types in Kazakhstan, we had to develop new and objective methods to study and compare their quality, so that we could understand the choices of material transport made by ancient people. These methods have been adopted for other regions and the data generated will contribute to future models linking dispersal to economic decisions and everyday mobility.
Finally, we modelled the success of dispersal through the corridor as a function of social strategies. The evolutionary agent-based model we produced suggests that a high degree of individual cooperation among the dispersing groups would be required to survive in the harshest climatic conditions of the last glacial cycle in the IMAC.
We began the project by developing a predictive model to improve the efficiency of finding Palaeolithic sites in karst landscapes. Using it, along with foot surveys, we discovered 95 unknown caves, in addition to 31 lithic scatters from 16 open air locations that were also found during our foot survey. We carried out 14 test excavations (11 in caves), concluding the mapping part of the project during the 2019 and 2021 field seasons.
We highlight several of these sites. In the Kazakh part of the Ili corridor that leads into China, we found the first stratified multi-component Pleistocene site, with layers that may reach the Middle Palaeolithic. 70 km west of Almaty, we found a new open-air loess site that documents human presence from the Upper Palaeolithic until about five thousand years ago.
In south Kazakhstan, Palaeolithic layers were found in two cave sites. The first preserves a late Middle and/or early Upper Palaeolithic layer, containing stone tools as well as animal bones with cut marks. Ancient DNA from these sediments may reveal the identity of these highly mobile populations. In the second cave, newly excavated layers show that people came here during the cold and dry environments of the Last Glacial Maximum (LGM). So far, no other occupations dating to this time period have been documented anywhere in Kazakhstan, making this a major breakthrough.
Finally, we excavated the remains of five human individuals dating to the early Holocene at a newly discovered cave site in the Sairam-Ugam National Park. Further excavations will elucidate the original context of deposition and possibly reveal further elements of the burial.
PALAEOSILKROAD also contributed to the public’s understanding of archaeology, both in Kazakhstan and on the international stage. In June 2022, we held a press conference at the site of Tuttybulaq, featuring all the major media outlets in Kazakhstan. Additionally, the PI and team held workshops on prehistory, stone tool analysis, and professionalisation for prehistory students at Kazakh National University. We were also featured by BBC Reel in a short documentary on the prehistoric origins of the Silk Road (https://youtu.be/DtcP6xeOwCg(opens in new window)) which has been viewed over 70000 times.
We highlight several of these sites. In the Kazakh part of the Ili corridor that leads into China, we found the first stratified multi-component Pleistocene site, with layers that may reach the Middle Palaeolithic. 70 km west of Almaty, we found a new open-air loess site that documents human presence from the Upper Palaeolithic until about five thousand years ago.
In south Kazakhstan, Palaeolithic layers were found in two cave sites. The first preserves a late Middle and/or early Upper Palaeolithic layer, containing stone tools as well as animal bones with cut marks. Ancient DNA from these sediments may reveal the identity of these highly mobile populations. In the second cave, newly excavated layers show that people came here during the cold and dry environments of the Last Glacial Maximum (LGM). So far, no other occupations dating to this time period have been documented anywhere in Kazakhstan, making this a major breakthrough.
Finally, we excavated the remains of five human individuals dating to the early Holocene at a newly discovered cave site in the Sairam-Ugam National Park. Further excavations will elucidate the original context of deposition and possibly reveal further elements of the burial.
PALAEOSILKROAD also contributed to the public’s understanding of archaeology, both in Kazakhstan and on the international stage. In June 2022, we held a press conference at the site of Tuttybulaq, featuring all the major media outlets in Kazakhstan. Additionally, the PI and team held workshops on prehistory, stone tool analysis, and professionalisation for prehistory students at Kazakh National University. We were also featured by BBC Reel in a short documentary on the prehistoric origins of the Silk Road (https://youtu.be/DtcP6xeOwCg(opens in new window)) which has been viewed over 70000 times.
On the methodological front, we have made significant progress beyond the state of the art in several areas:
1) Predictive modelling of caves and rockshelters for archaeological survey;
2) Mapping the distribution of sources of stone raw materials for making stone tools and understanding the economic choices of ancient humans;
3) Applying concepts from engineering and materials science to assess raw material quality.
We have also produced a large amount of new data and conclusions about human occupation of the IAMC during the Stone Age, making a significant progress beyond the state of the art in the following areas:
1) Understanding the structure and biases in the archaeological record of Central Asia;
2) Establishing the chronology of human occupation in cave sites in the Qaratau and Tian Shan Mountains, including during the Last Glacial Maximum;
3) Finding the oldest human remains so far discovered in Kazakhstan;
4) Finding the first (open-air) Palaeolithic sites in the Altyn Emel and Tarbagatai Mountains;
5) Extending the chronology of the Palaeolithic occupation in the Kazakh Altai to nearly 50 thousand years.
Last but not least, we were the first project explicitly built upon the Paleo Core international data standard for palaeoanthropology. We are working on a paper to describe the method and challenges to interoperability of data from large field projects, as well as publishing the data themselves.
1) Predictive modelling of caves and rockshelters for archaeological survey;
2) Mapping the distribution of sources of stone raw materials for making stone tools and understanding the economic choices of ancient humans;
3) Applying concepts from engineering and materials science to assess raw material quality.
We have also produced a large amount of new data and conclusions about human occupation of the IAMC during the Stone Age, making a significant progress beyond the state of the art in the following areas:
1) Understanding the structure and biases in the archaeological record of Central Asia;
2) Establishing the chronology of human occupation in cave sites in the Qaratau and Tian Shan Mountains, including during the Last Glacial Maximum;
3) Finding the oldest human remains so far discovered in Kazakhstan;
4) Finding the first (open-air) Palaeolithic sites in the Altyn Emel and Tarbagatai Mountains;
5) Extending the chronology of the Palaeolithic occupation in the Kazakh Altai to nearly 50 thousand years.
Last but not least, we were the first project explicitly built upon the Paleo Core international data standard for palaeoanthropology. We are working on a paper to describe the method and challenges to interoperability of data from large field projects, as well as publishing the data themselves.