STABLE ISOTOPES IN PRECIPITATION AND GROUND WATER IN THE YUCCA MOUNTAIN REGION, SOUTHERN NEVADA: PALEOCLIMATIC IMPLICATIONS

摘要

Unadjusted ages of ground-water samples indicate that most recharge in the Yucca Mountain and Amargosa Desert areas of southern Nevada may have occurred between 18,500 and 9000 years before present. Comparison of the stable-isotope δ18O‒δD) concentrations in this water with stable-isotope concentrations in precipitation in the southern Nevada area indicates that ground-water recharge occurred by infiltration of cold season precipitation. Infiltration of snowmelt along the bottom of Forty mile Canyon seems to be the most likely recharge mechanism for Yucca Mountain ground water. Ground-water recharge in southern Nevada was nearly synchronous with the last lake cycle in the Lahontan basin in northern Nevada.