PEOPLE3k: Demographic Boom and Bust Cycles of Coastal Hunter-gatherers Cycles Track Shifting Upwelling Conditions in Northern Chile

Summary

This is an abstract from the "Global Perspectives on Climate-Human Population Dynamics During the Late Holocene" session, at the 84th annual meeting of the Society for American Archaeology.

Extensive archaeological shell middens can be found throughout coastal northern Chile, where they span more than 9,000 years. They contain abundant terrestrial plants and shellfish remains and can often accumulate very quickly and/or episodically. We use multiple radiocarbon dates to measure local radiocarbon deviations (R) between marine and atmospheric ages along a given stratigraphic horizon. Such estimates are then used to calculate regional marine reservoir departures from the global marine 14C calibration curve (ΔR). Previous research has shown that ΔR estimates can be used to reconstruct local upwelling conditions. A steady increase in upwelling and colder coastal waters drove increased marine productivity along with an almost constant increase in coastal hunter-gatherer populations from 9,300 to 5,500 cal yr BP. Major shifts in upwelling associated with unstable coastal ecosystems drove demographic collapse of coastal hunter-gatherers from 5,500 to 4,700 years ago- with populations declining until c. 2,500 cal yr BP. Our upwelling records shed new light on how the coastal ecosystems of northern Chile have evolved and co-adapted with prehistoric human societies, and show how these changes relate to global climate change, such as the onset and intensification of ENSO over the last 9,000 years.

This Resource is Part of the Following Collections

• Global Perspectives on Climate-Human Population Dynamics During the Late Holocene   •
• Society for American Archaeology 84th Annual Meeting, Albuquerque, NM (2019)

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Record Identifiers

Abstract Id(s): 25035