Oxygen isotope analysis in a land of environmental extremes: The complexities of isotopic work in the Andes

The Andes, which have a wide variety of diverse and distinct environmental zones ranging from the hyperarid coast to the high-altitude altiplano, are an ideal region in which to explore the use of oxygen isotope analyses to elucidate archaeological residential mobility. However, some questions remain, including the mobility of water through the environment, the seasonal and annual variability of precipitation in the past, and the role of water storage and beverage preparation techniques. Here, the advantages and disadvantages of oxygen isotope analysis in the Andes, and beyond, will be explored using oxygen isotope data from archaeological human enamel and bone from Peru, Bolivia and Chile (c. AD 1-1500). Although strontium isotope values from this region vary according to regional geology, oxygen isotope data do not always follow expected patterns based on known environmental variables, and probably reflect the movement of water throughout the Andes, complicating its use as a tool to identify human migration in the past.