Hydrochemical and stable isotope study of groundwater in the Saint Catherine-Wadi Feiran area, south Sinai, Egypt

The groundwater of the investigated area resides in both crystalline rocks and alluvial deposits. The salinity of the collected water samples is governed by the rock type, air-borne dust and marine aerosols. The groundwater in the monzonite is more saline than tha: in the alluvium, granite and volcanic rocks. It is characterised by a high sulphate content due to the oxidation of sulphide bearing minerals. The water was found to be suitable for drinking and agricultural purposes. The groundwater samples have an 18O and deuterium composition similar to that of precipitation, which is presumably the main source of the groundwater recharge in this area. In addition, fossil water (palaeowater) may also play a role in the recharge of the investigated water via faults, dykes and joints which exist in the area. The deuterium excess values observed in some of investigated groundwater samples are much lower than that for the Mediterranean area. This is evidence of evaporation before infiltration to the aquifer. © 1998 Elsevier Science Limited.