Marine Carbon Reservoir Age estimates for the Far Southern Coast of Peru

Abstract

In order to estimate the apparent age of seawater (R) and the corresponding local offset from the global marine radiocarbon calibration curve (Delta-R) on the far south coast of Peru for 2 periods in the past, 6 pairs of associated marine shell and unburned wood samples from archaeological excavations at Loreto Viejo were 14C dated. Three pairs from about cal AD 1280-1380 indicated larger and more variable Delta-R estimates than have been obtained for other periods in nearby regions, suggesting that Delta-R may vary considerably over space and/or time. Three pairs from about 1870-1680 cal BC yielded consistent shell dates, but only one reasonable terrestrial date and Delta-R estimate, probably due to stratigraphic mixing in antiquity. The one early Delta-R estimate falls slightly outside the range of the later ones, suggesting either still greater spatial variability in Delta-R, or some temporal variability.