Isotopic Research in the Altai Mountains

Mongolia and the Altai Mountains were closely connected in the Upper and, probably, Middle Paleolithic: people migrated across these regions and throughout Central Asia and southern Siberia. These migrations represent human dispersals stimulated by several causes, including climate change and the movement of game animals. People transported animal bones, minerals and organic raw materials, and items of personal ornament on their journeys. Some such ornaments were apparently transported over long distances as objects of exchange or markers of social networks. In order to better interpret the significance of such transport, it is crucial to compile Strontium (Sr) isotopic maps of the areas under study.

Although the Covid-19 pandemic had shut down international and our plans to take more Sr samples for isotopic mapping in Mongolia were derailed, but managed to proceed with implementing the project on Russian territory in the Altai Mountains. We collected samples at 41 localities. Choosing each sampling locality was complex and based on several criteria: 1) We chose localities in different kinds of geological formations, because geology directly influences isotopic composition of water, soil and vegetation. Having detailed geological maps, we faced the problem of discrepancies, because some areas were mapped only remotely using satellite imagery. Fortunately, we were able to collaborate with two superb specialists in rock formation. 2) We sampled water, vegetation, and soil at each locality, but the Altai region is an intensively agricultural zone today. To avoid contamination by fertilizer and other agro-chemicals, we needed to penetrate deeper and higher in each valley, to access areas without agricultural fields. Sometimes water sources were absent in such areas, and we sampled vegetation and soil only. 3) A Sr isotopic map is meant to be detailed so, ideally, samples need to be taken every 5 km in each river valley. We knew from the outset that such high-resolution analysis was beyond our means since 87Sr/86Sr ratio analysis is prohibitively expensive. Thus, during this initial stage of our project we chose different areas in the Altai Mountains to enhance our basic understanding of 87Sr/86Sr ratios in the region.

Strontium sampling localities in the Altai Mountains (map by Andrey Vishnevsky)

We collected samples in areas near the Russian border with Kazakhstan (districts near the Mongolian border were closed and off-limits) and locations surrounding archaeological sites, including Okladnikov, Denisova, Maloyalomanskaya and Ust’-Kanskaya caves, Kara-Bom, Ust’-Karakol sites and other areas.

Okladnikov Cave. Geochemist Dr. Irina Vishnevskaya and geologist Dr. Evgeny Mikheev
Ust’-Kanskaya Cave
Research team visiting Denisova Cave. Thanks to Dr. Maksim Kozlikin (in red helmet) for a wonderful excursion!
The Kara-Bom site

Overall, we collected 111 samples from 41 localities. All are currently under analysis in the “Geoanalyst” Common Use Center of the Ural Branch of the Russian Academy of Sciences in Ekaterinburg. We also collected a number of rock samples from primary formations, when differences between geological maps and the real geological situation were detectable.

Azurite and malachite
Attempting to dry samples
Expedition camp on the Katun’ River
The best selfie ever :))
The Malaya Gromatukha River
Dr. Irina Vishnevskaya collecting a water sample

Participants:

Arina Khatsenovich, initiator of the survey, but mostly a tourist

Irina Vishnevskaya, Queen of Isotopes

Evgeny Mikheev, guy with a big geological hammer

Andrey Vishnevsky, Head of the Geological Museum and Senior Researcher in the Institute of Geology and Minerology, SB RAS and Novosibirsk State University. Our petrographer, GIS specialist, cook and driver.

and Evgeny Rybin, who provided his invaluable advice from home!

THE END!

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