Near-surface accumulations of secondary carbonates are common in the soils and sediments of the Yucca Mountain area. These carbonates contain small amounts of uranium that allow dating by the uranium-series disequilibrium method. Preliminary results from the Yucca Mountain area indicate that the U-series methods can (1) identify multiple episodes of tectonic fracturing, (2) provide a chronologic framework for paleoclimatically significant eolian deposits, and (3) place constraints on the probable source of waters from which the carbonates precipitated.