Globigerina Limestone

Malta’s rock sequence is somewhat quite simple. It is divided into five main layers of sediments. As the name goes, the upper coralline limestone layer is found on the top side of rock sequence, followed by the Greensand Formation, the Blue Clay layer, the Globigerina Limestone layer, and last but not least, the Lower Coralline Limestone layer. 

Each layer of rock is unique from the other. The distinction in rock formations is due to the time periods when the rock layer started to form, thus for instance, the strength of protection from erosion depends on the rock hardness.

One of the layers of rock used extensively for construction and decoration on the Maltese Islands is the Globigerina Limestone. This particular layer of rock is situated over the Lower Coralline Limestone. The width of this layer varies from approximately 66 feet in Fort Chambray, Għajnsielem in Gozo to 656 feet on the other side of the Archipelago of Malta, which is in Marsaxlokk in Malta

The Globigerina limestone is a supple fine grained layer. This is quite different from the Lower Globigerina Limestone. In fact, when weathered, studies show that the Globigerina Limestone forms gentle slopes. The Globigerina Limestone is majorly composed of Globigerina, as well as some marine micro-organisms. This reflects on the event which must have happened during its formation 34 million years ago; A mass of land must have sunk off since the components suggest sea-depths of around 600 feet.