Hydrology and Land Surface Studies
One million year old groundwater in the Sahara revealed by krypton-81 and chlorine-36
Article first published online: 12 MAR 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 5, March 2004
How to Cite
2004), One million year old groundwater in the Sahara revealed by krypton-81 and chlorine-36, Geophys. Res. Lett., 31, L05503, doi:10.1029/2003GL019234., et al. (
- Issue published online: 12 MAR 2004
- Article first published online: 12 MAR 2004
- Manuscript Accepted: 12 FEB 2004
- Manuscript Revised: 28 JAN 2004
- Manuscript Received: 8 DEC 2003
 Measurements of 81Kr/Kr in deep groundwater from the Nubian Aquifer (Egypt) were performed by a new laser-based atom-counting method. 81Kr ages range from ∼2 × 105 to ∼1 × 106 yr, correlate with 36Cl/Cl ratios, and are consistent with lateral flow of groundwater from a recharge area near the Uweinat Uplift in SW Egypt. Low δ2H values of the 81Kr-dated groundwater reveal a recurrent Atlantic moisture source during Pleistocene pluvial periods. These results indicate that the 81Kr method for dating old groundwater is robust and such measurements can now be applied to a wide range of hydrologic problems.