OSL ages of upper Quaternary eolian sand and paleosols, northwest Albuquerque Basin, New Mexico

Abstract

Upper Pleistocene and Holocene eolian sand mantles the topography in the northwestern Albuquerque Basin. A series of 12 OSL ages from surficial deposits along the Paseo del Volcan corridor, Rio Rancho, Sandoval County, indicates that the main body of eolian sand was deposited with a thickness of 0.5–1.4 m during the period from 16 to 10 ka. A red calcic paleosol with stage I carbonate morphology formed in the sand during the Holocene. The OSL-dated sand has a net sedimentation rate of 0.026 cm per year. Eight archaeological sites with features that intrude into the upper Pleistocene eolian sand are radiocarbon dated 4,600–580 14C yrs b.p. The surface of the sand and its paleosol are truncated by sheet erosion. The top portions of features at the archaeological sites as well as most artifacts have been removed by erosion. Underlying the upper Pleistocene sand is an eroded eolian silty sand with a pink calcic paleosol with stage II carbonate morphology and an OSL estimated age ~130 ka. The eolian sand covers an alluvial/colluvial gravelly sand containing a paleosol with stage III carbonate morphology that may be Miocene. The OSLdated eolian cover sand along the Paseo del Volcan corridor has few equivalents in the region.