Stratigraphic, sedimentologic, and pedologic studies of beach ridge and lacustrine deposits indicate that up to five times during the Holocene, shallow lakes covered Silver Lake playa in southeastern California for periods of years to decades. The two youngest lacustrine events (at about 390 ± 90 yr B. P. and 3620 ± 70 yr B. P.) coincide with the early and late Neoglacial episodes of North America. Increasing evidence in recent years from other nonglaciated areas leads us to conclude that the effects of these climatic episodes were much more widespread than previously thought. The climate during these episodes was characterized by an increased frequency of winter storms in the southwestern United States, causing wetter conditions that affected diverse, hyperarid environments in the Mojave Desert and adjacent regions. We propose that this wide areal coverage was caused by large-scale, winter atmospheric circulation patterns, which are probably related to changes in sea-surface temperatures and oceanic circulation in the eastern North Pacific Ocean.
Bibliographical noteFunding Information:
We thank Bruce Allen for helping with fieldwork and fruitful discussions. Bruce Harrison and Lisa Ely improved earlier versions of the manuscript. Comments by Ci. I. Smith and an anonymous reviewer are truly appreciated. This research was partially funded by the USGS through the New Mexico WRRI, Award 14-08-OOOl-Gl312 to S.G.W., R.Y.A., and L.D.M. Support and help during field work from CSU Desert Studies Center at Zzyzx and financial support from SRAC at University of New Mexico (to Y.E. and W.J.B.), ALPHA (Department of Geosciences, University of Arizona), and the American Water Foundation (to Y.E.) are appreciated.