A bio-available strontium isoscape for eastern Beringia: a tool for tracking landscape use of Pleistocene megafauna |
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| Authors: | Juliette Funck Clement Bataille Jeffrey Rasic Matthew Wooller |
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| Institution: | 1. Alaska Stable Isotope Facility, Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK, USA;2. Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, ON, Canada;3. National Park Service, Fairbanks, AK, USA |
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| Abstract: | Numerous paleoecological questions concern the mobility of ancient fauna in eastern Beringia. Strontium (Sr) isotope ratio (87Sr/86Sr) analysis has emerged as a powerful tracer for determining the provenance of ancient biological materials. However, it is important to characterize 87Sr/86Sr variation across a landscape. We measured the 87Sr/86Sr composition of teeth from present-day, herbivorous rodents (n = 162) sampled from across eastern Beringia to estimate bio-available 87Sr/86Sr values. We compiled these data with the very limited number of previously published 87Sr/86Sr values from the region. We then used this dataset and a machine learning, random-forest regression to predict bio-available 87Sr/86Sr variations across eastern Beringia. As a case study using our new 87Sr/86Sr map (isoscape), we measured the 87Sr/86Sr and oxygen stable isotope values (δ18O) of five radiocarbon-dated steppe bison from eastern Beringia and compared these to our 87Sr/86Sr isoscape and a δ18O isoscape to estimate the probable landscape use of these ancient fauna. Our model and isoscape provide important foundations for a wide range of additional applications, including studies of the paleo-mobility of other fauna, ancient people and present-day fauna in eastern Beringia. |
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| Keywords: | Alaska bison machine-learning provenance rodents |
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