One million year old groundwater in the Sahara revealed by krypton-81 and chlorine-36

	Become an AGU Member Subscribe to AGU Journals



Read Full Article (file size: 258328 bytes) Cited by GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L05503, doi:10.1029/2003GL019234, 2004 One million year old groundwater in the Sahara revealed by krypton-81 and chlorine-36 N. C. Sturchio Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, Illinois, USA X. Du Physics Division, Argonne National Laboratory, Argonne, Illinois, USA Physics Department, Northwestern University, Evanston, Illinois, USA R. Purtschert Institute of Physics, University of Bern, Bern, Switzerland B. E. Lehmann Institute of Physics, University of Bern, Bern, Switzerland M. Sultan Department of Geology, State University of New York at Buffalo, Buffalo, New York, USA L. J. Patterson Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, Illinois, USA Z.-T. Lu Physics Division, Argonne National Laboratory, Argonne, Illinois, USA P. Müller Physics Division, Argonne National Laboratory, Argonne, Illinois, USA T. Bigler Institute of Physics, University of Bern, Bern, Switzerland K. Bailey Physics Division, Argonne National Laboratory, Argonne, Illinois, USA T. P. O'Connor Physics Division, Argonne National Laboratory, Argonne, Illinois, USA L. Young Chemistry Division, Argonne National Laboratory, Argonne, Illinois, USA R. Lorenzo Institute of Physics, University of Bern, Bern, Switzerland R. Becker Department of Geology, State University of New York at Buffalo, Buffalo, New York, USA Z. El Alfy Egyptian Geological Survey and Mining Authority, Cairo, Egypt B. El Kaliouby Department of Geology, Ain Shams University, Cairo, Egypt Y. Dawood Department of Geology, Ain Shams University, Cairo, Egypt A. M. A. Abdallah Department of Geology, Ain Shams University, Cairo, Egypt Abstract 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. Received 8 December 2003; accepted 12 February 2004; published 12 March 2004. Index Terms: 1035 Geochemistry: Geochronology; 1832 Hydrology: Groundwater transport; 9820 General or Miscellaneous: Techniques applicable in three or more fields. Read Full Article (file size: 258328 bytes) Cited by Citation: Sturchio, N. C., et al. (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. Copyright 2004 by the American Geophysical Union.

Abstract