It is the oldest rock layer. It was formed during the Upper Oligocene around 30 to 25 million years ago. It is given a pink colour on the geological map. It is exposed at a thickness of 140 m above the sea level in fact it is found on the vertical cliffs of Xlendi, Gozo. It mainly formed from Coralline Algae. This is an indicated that it formed in shallow water. It is a hard, pale grey coloured limestone. It is called Lower Coralline Limestone as it contains some beds with fossils corals and common remains of marine calcareous algae. It can be over 140 m thick and its base it not seen above the sea.
Below: An impressive photo of a boulder of lower Coralline limestone found in Wied Babu.