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Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

Quaternary Research

By:
, , , , , ,
DOI: 10.1016/j.yqres.2008.01.003

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Abstract

Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?–9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900–13,800 and 12,700–9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Paleowetlands and regional climate change in the central Atacama Desert, northern Chile
Series title:
Quaternary Research
DOI:
10.1016/j.yqres.2008.01.003
Volume
69
Issue:
3
Year Published:
2008
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Contributing office(s):
Branch of Regional Research-Western Region
Description:
18 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
343
Last page:
360
Country:
Chile
Other Geospatial:
Atacama Desert;Andes Mountains