A Evaluation Of Isotopic And Geochronologic Data On The Groundwater

1829 Words Feb 1st, 2016 8 Pages
This paper presents an evaluation of isotopic and geochronologic data on the groundwater in Eastern Sahara that have been collected by various projects in addition to our recent collected dating groundwater samples. Nubian Sandstone Aquifer System (NSAS) of northeast Africa is believed to have been recharged in previous wet climatic periods in the Quaternary Period. However, the isotopic (O & D) signatures of the groundwater samples show that the aquifer is still receiving modern recharge in some regions (central and north Sudan, the Eastern Desert and Sinai). These regions have a rainfall that feed the aquifer during the current dry climate. The groundwater source ranges between paleowater of the glacial wet climate to paleowater mixed with precipitation of warm and dry climates and/or Nile water, in addition to the modern groundwater of evaporated flash flood or precipitation in the shallow alluvial aquifers. Central Sudan, Eastern Desert and Sinai have a wide range of isotopic signatures reflecting paleowaters, mixing and modern groundwaters. The isotopic signatures of north Sudan and south of the Uweinat–Aswan uplift indicates replenishment by groundwater flow from the south that is hindered by the uplift. Young C-14 ages for groundwater samples were reported from east Uweinat (~1.8–11.7 kyr) and from northern Sudan (~50 kyr), reflecting the modern recharge in this area to the south of the Uweinat-Aswan uplift. The groundwater of the Western Desert shows the highest…
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