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

N. C. Sturchio·X. Du·R. Purtschert·B. E. Lehmann·M. Sultan·L. J. Patterson·Z. -T. Lu·P. Mueller·T. Bigler·K. Bailey·T. P. O'Connor·L. Young·R. Lorenzo·R. Becker·Z. El Alfy·B. El Kaliouby·Y. Dawood·A. M. A. Abdallah
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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 \~2x10^5 to ~1x10^6 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 delta-2H 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.

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N. C. Sturchio, X. Du, R. Purtschert, B. E. Lehmann, M. Sultan, L. J. Patterson, Z. -T. Lu, P. Mueller, T. Bigler, K. Bailey, T. P. O'Connor, L. Young, R. Lorenzo, R. Becker, Z. El Alfy, B. El Kaliouby, Y. Dawood, A. M. A. Abdallah. 2004-02-18. One million year old groundwater in the Sahara revealed by krypton-81 and chlorine-36. https://doi.org/10.1029/2003gl019234

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