Shoreline Soil Stratigraphy, Landscape Evolution, and Application to Archaeology Studies: White Sands National Monument, New Mexico
Eolian gypsum soils that have formed on the paleo-shorelines of Lake Otero in the White Sands Dune Fieldare valuable archives of past climates. A recent geoarchaeological study on the eastern margin of the paleolake examined these deposits using geological and pedological approaches, includingstratigraphy, soil description and characterization. Five pedostratigraphic units were identified,described, and constrained in time based on relative stratigraphy and radiocarbon dating of geologic deposits and hearth features within archaeological sites. Preliminary results indicate that the formation of these eolian soils reflect changes in paleo-lake levels, shoreline deflation, and dune field development that occurred from 14 ka to 5 ka rybp. Topographic position, as well as, morphological differences between these eolian soilssuggest that lake margin sand sheets formed in a step-wise fashion as the lake retreated at the end of the last Ice Age. The differences in soil development exhibited by these eolian soils can be used to correlate stratigraphy of buried and modern soil surfaces along the paleo-lake margin. To adequately evaluate the shoreline sand sheets for the preservation of cultural resources, future studies can use the stratigraphic relationships established by this research effort to more effectively isolate areas that could contain an intact vertical archaeological record.
Six pedostratigraphicunits were identified,described, & constrained in time based on relative stratigraphy & radiocarbon dating of geologic deposits and hearth features within archaeological sites.
Idealized schematic showing the development of eolian gypsum soils that have formed on the paleo-shorelines of Lake Otero with geoarchaeological interpretations. Vertical exaggeration and overstated horizon thicknesses were used to show differences in soils. Soils were constrained in time based on relative stratigraphy and radiocarbon dating of geologic deposits and hearth features within archaeological sites.