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Highly Variable Freshwater Reservoir Offsets Found along the Upper Lena Watershed, Cis-Baikal, Southeast Siberia

Published online by Cambridge University Press:  23 February 2016

Rick J Schulting*
Affiliation:
Research Laboratory for Archaeology and the History of Art, Dyson Perrins Building, University of Oxford, South Parks Road, Oxford OX1 3QY, United Kingdom
Christopher Bronk Ramsey
Affiliation:
Research Laboratory for Archaeology and the History of Art, Dyson Perrins Building, University of Oxford, South Parks Road, Oxford OX1 3QY, United Kingdom
Vladimir I Bazaliiskii
Affiliation:
Department of Archaeology and Ethnography, Irkutsk State University, Karl Marx Street 1, Irkutsk 664003, Russia
Andrzej Weber
Affiliation:
Department of Anthropology, 13-15 H.M. Tory Building, University of Alberta, Edmonton, Alberta T6G 2H4, Canada
*
2Corresponding author. Email: rick.schulting@arch.ox.ac.uk.

Abstract

A program of paired dating of human and faunal remains on a sample of 11 prehistoric (Mesolithic/Neolithic to Early Bronze Age) graves in the Upper Lena basin, southeast Siberia, was initiated to investigate the freshwater reservoir effect (FRE). The results show the presence of a substantial but highly variable offset, ranging from 255 to 1010 14C yr. In contrast to previous studies centered on Lake Baikal and the Angara River, human stable nitrogen isotope values show little or no correlation with the radiocarbon offset, despite the clear trophic differences seen in δ15N between terrestrial and aquatic sources of protein in the region's isotope ecology. However, stable carbon isotope measurements show a moderate negative correlation of some predictive value (r = −0.70, p = 0.016, df = 10). Two different regression equations have been calculated, the first using human δ13C values for the entire data set (r2 = 0.49) and the second, using both δ13C and δ15N values, limited to the Early Bronze Age of the southern Upper Lena (r2 = 0.84, p = 0.030, df = 5). The source of the old carbon in the Upper Lena River system is not clear. While the river flows over carbonate bedrock and is moderately alkaline, we suggest that old terrestrial carbon entering the riverine foodweb through bank erosion and other processes is a more likely candidate for the majority of the 14C offset.

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Articles
Copyright
Copyright © 2015 by the Arizona Board of Regents on behalf of the University of Arizona 

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