Soil genesis on beach ridges of pluvial Lake Mojave: Implications for Holocene lacustrine and eolian events in the Mojave Desert, Southern California
Abstract
Summary. Silver Lake and Soda Lake playas, Mojave Desert, California, are bounded by locally well preserved shoreline features that reflect the presence of pluvial Lake Mojave. A well preserved sequence of five beach ridges is present in the northernmost part of Silver Lake playa. Radiocarbon dating show that the topographically highest three beach ridges range from <13,600 to approximately 9,000 years in age. Soils have formed primarily in a sandy eolian mantle that was deposited on top of the higher three beach ridges after the drying of Lake Mojave, between 6,000 and 9,000 yrs B.P. Minimal soil development had occurred in gravelly beach deposits prior to this time period. Weakly developed soils occur in gravelly sandy deposits of the two lower, undated beach ridges. Morphological, textural, and chemical analyses of the soils indicate that eolian processes have strongly influenced soil development on beach ridges. The accumulation of eolian sand on the gravelly beach ridge soils influences pedogenesis because of the lower permeability and shallower depth of water infiltration in sand compared to that of the highly permeable beach gravels. Soil formation has also intensified by the presence of playas that provided a source of silt, clay and salts. The degree of soil development in the lowest beach ridges indicates several lake stands in Silver Lake playa during the past 6,000 years. These may be as young as the latest Holocene, as supported by radiometrically dated lacustrine sediments from Silver Lake playa.
- Publication:
-
Catena
- Pub Date:
- 1992
- DOI:
- 10.1016/0341-8162(92)90018-7
- Bibcode:
- 1992Caten..19...77M