Temporal and Spatial Dietary Variability in the Prehistoric Lower and Middle Osmore Drainage: The Carbon and Nitrogen Isotope Evidence

Authors

Karin L. Sandness, University of Nebraska-Lincoln

First Advisor

Karl J. Reinhard

Committee Members

Marion O'Leary, Alan Osborn, Larry Tieszen

Date of this Version

8-1992

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Arts

Major: Anthropology

Under the supervision of Karl J. Reinhard

Lincoln, Nebraska, August 1992

Comments

Copyright 1992, Karin L. Sandness. Used by permission

Abstract

Skeletal material from six sites representing human occupation in the Osmore drainage of southern Peru, circa A.D. 50 to 1400, was analyzed for carbon and nitrogen isotopes. The δ¹³C and δ¹⁵N values observed in the study indicate-spatial and temporal variability in diet. Specimens from the lower valley are, in general, more positive in both carbon and nitrogen than those of the middle valley, with the most positive values being present in specimens from the coastal Chiribaya site, San Geronimo. The data suggest, however, that all populations in the drainage experienced shifts in diet through time. Samples from the middle valley show a trend towards more positive δ¹³C values and less positive δ¹⁵N values, suggesting increased maize consumption, with particular emphasis on this food source during the Middle Horizon Period (A.D. 700-900). A similar trend toward more positive δ¹³C values is observed for the lower valley. However, the o15N values also appear to increase through time for lower valley populations, suggesting a more comprehensive utilization of marine resources. Dietary percentages calculated for the samples using a linear mixing model with end values from modem analogues of marine and terrestrial food sources from northern Chile refine the dietary differences suggested by the human isotope values, indicating a heavy to nearly total reliance on marine foods for lower Osmore prehistoric populations and a diet of varied resources from both the coast and altiplano, with an emphasis on maize, for middle valley peoples. Factors of geographic location, shifts in socioeconomic control and migration are discussed relative to the isotopic data of the study.

Advisor: Karl J. Reinhard