Evidence for eolian deposition in the sandy uplands of East Texas and the implications for archaeological site integrity

Abstract

Abstract Unconsolidated sands form an extensive mantle across large parts of East Texas uplands. The exact geomorphic processes responsible for their formation are not known, but, on hill summit settings, these deposits are interpreted as either eolian sediments or as sand liberated by the in situ weathering of the underlying Tertiary age fluvial‐deltaic sandstone bedrock. In order to identify which of these is the most likely formation process, we used detailed sedimentary analysis coupled with optically stimulated luminescence (OSL) dating of the sediment on seven samples from a single profile in Lee County, Texas. All OSL samples demonstrated that samples had been exposed to significant sunlight before they were deposited in the middle to late Holocene, thereby ruling out an in situ weathering origin. These results indicate that eolian sedimentation occurred during the middle to late Holocene and that archaeological sites within these deposits may be in good context and worthy of excavation. © 2002 John Wiley & Sons, Inc.