Tree Ring Isotope Record of Climate Change at the Ramaditas site in the Atacama Desert of Northern Chile

Summary

The Ramaditas archaeological site in the Atacama Desert of northern Chile provides evidence for cultural adaptations during wetter environmental conditions in an otherwise arid environment. From 2.0 – 2.5 kyr B.P., regional population increased and a cultural shift toward agricultural based communities occurred. Tree samples collected from the site provide a high-resolution record of increased water availability as recorded by tree ring oxygen and carbon isotopes. Prosopis tamarugo logs from structures and stumps in ancient irrigated agricultural fields show a range of δ18O values from 22.8 to 39.4‰. The change in oxygen isotope values is significantly greater than the 33.5 to 34.6‰ range recorded in modern and early Holocene trees. Precipitation runoff and infiltration in the Andean highlands to the west of the site recharges the lowland Pampa del Tamarugal aquifer. Hydroclimate anomalies leading to wetter environmental conditions during Central Andean Pluvial Events in the region have been attributed to ENSO-like variability. Frequency analyses of annual and sub-annual isotope values suggest decadal trends in climate forcing mechanisms. The timing of these paleoenvironmental and cultural events as recorded by our tree-ring isotope record demonstrate the dynamics between human societies and the environment.

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This Resource is Part of the Following Collections

• Society for American Archaeology 80th Annual Meeting, San Francisco, CA (2015)

Keywords

Spatial Coverage