Time-variant hydrogeologic and geochemical study of selected thermal springs in western Nevada

Abstract

Infiltrating waters take -from 24 weeks to less than two weeks to reach the watertables of individual thermal systems, based on temporal variability of physical and chemical parameters. Steamboat and Walley’s hot springs showed nearly instantaneous responses to precipitation events; conversely, Farad and Saratoga hot springs showed lagged responses of six to 24 weeks respectively. Chemical and isotopic variability suggests that thermal waters have appreciable near-surface mixing, particularly at springs that show rapid responses to precipitation events. Stable isotopes of oxygen and hydrogen ranged from -16.3 to -11.0 and -132.0 to -102.0 respectively, implying that recharge waters are derived from widely varying elevations. The thermal systems derive most of their recharge from the Sierra Nevada.