Shallow Subsurface Evidence for Postglacial Holocene Lakes at Ivanpah Dry Lake: An Alternative Energy Development Site in the Central Mojave Desert, California, USA

Dry lakes, or playas, in the American Southwest have become important locations for alternative energy solar electric generation systems. Many of these playas have not been investigated for past environmental conditions prior to their development, causing alterations to the shallow sediment profile and altering subsurface chemical and physical data important to recent geologic and hydrologic histories of these areas. Recent studies of these features commonly have focused on surficial data with little or no subsurface geologic data to delineate wet and dry cycles of playa lakes. Many of the playa margins are covered with a surficial layer of alluvial and/or aeolian sands varying in thickness, which could interfere with correct interpretations of data gathered only on the surface material on these lands. Over the past 13,000 years Ivanpah Dry Lake has had at least three episodes of lake highstands up to ~10m in response to climate changes, based on data in this study with the oldest episode dates to ~13,000 cal yrs BP. This study has a link to other sites as many other playas are slated for energy development and could endure subsurface data alteration during site reworking and occupation, resulting in a loss in their collective historical geologic and hydrologic records if more complete studies of important sites are not carried out before developments begin.