Geology

The land was formed in a recent geologic era. In the south, limestone rises in a ong, north-oriented dome that lies beneath the surface. It is within and below this formation that the principal oil fields, Kuwait’s most important natural resource, are located. In the west and north, layers of sand, gravel, silt, and clay overlie the limestone to a depth of more than 210 meters. The upper portions of these beds are part of a mass of sediment deposited by a great wadi whose most recent channel was the Wadi al Batin, the broad shallow valley forming the western boundary of the country. On the western side of Ar Rawdatayn geological formation, a freshwater aquifer was discovered in 1960 and became Kuwait’s principal water source. The supply is insufficient to support extensive irrigation, but it is tapped to supplement the distilled water supply that fills most of the country’s needs. The only other exploited aquifer lies in the permeable zone in the top of the limestone of the Ash Shuaybah field south and east of the city of Kuwait. Unlike water from the Ar Rawdatayn aquifer, water from the Ash Shuaybah aquifer is brackish. Millions of liters a day of this water are produced for commercial and household purposes.