It was formed in the Middle to Upper Miocene Period. The Colour code is blue and it approximate age is 13 to 12 million years. It is exposed at a thickness of 65m above sea level in particular locations such as Ghajn Tuffieha and Gnejna. It is impervious therefore it does not allow water to pass through it. Thus it helps in the formation of the perched aquifer. It is a very soft and meabble when wet.
Below: A photo of the Qarraba headland as seen from Gnejna Bay. In geological terms the headland is composed of a blue clay talus and a upper coralline limestone plateau.