Large Holocene lakes and climate change in the Chihuahuan Desert

Lake-level variations preserved as beach ridges in the Laguna El Fresnal and Laguna Santa Maria subbasins, northern Mexico, record millennially spaced episodes of increased precipitation during the Holocene epoch. We find that the early, middle, and late Holocene were punctuated by periods wet enough to establish large pluvial lakes in currently dry basins in the Chihuahuan Desert; the largest dated pluvial lake covered similar to 5650 km(2) during the early Holocene. Constructional beach ridges in these subbasins are 221 +/- 33 C-14 yr B.P. (Little Ice Age equivalent), 3815 +/- 52 to 4251 +/- 59 C-14 yr B.P. (early Neoglacial), 6110 +/- 80 to 6721 +/- 68 C-14 yr B.P. (mid-Holocene), and 8269 +/- 64 to 8456 +/- 97 C-14 yr B.P. (early Holocene), dates that correlate with other millennially spaced wet or cold events in the Northern Hemisphere. We attribute these wet episodes to increased precipitation, cooler temperatures, and reduced evaporation following southward shifts in winter storm tracks, which are related to long-term El Nino-Southern Oscillation variability during the Holocene.