Limestone and Chalk Features

The features of every landscape are shaped by its underlying geology. The Yorkshire Dales, the Chalk Downs and the White Cliffs of Dover - each of these is a famous British landscape that is entirely shaped by an underlying geology of chalk or limestone.

Limestone is composed of the skeletal remains of marine creatures that died millions of years ago. The bodies of dead corals, molluscs and other animals have built up on the sea floor over time into layers that can be hundreds of meters deep. Sometimes entire reefs can be preserved as a window into the past.

Limestone has a variety of uses - it’s the raw material in cement, mortar, concrete, quicklime and slaked lime. It's also an ingredient in glass making and is added to bread, toothpaste, plastics, paint, tiles, medicines and cosmetics. On top of that it is used as a means of neutralizing acids in water and soils and as a control for pollution. Even the humble tortoise, as well as some other animals, may be fed limestone as a calcium supplement!

For all its versatility, probably the most visible use of limestone is as a building material. Some of its features - its pure white color and the flashes of light as the crystals present in some limestone catch the Sun - have made it a prized building material. Cathedrals, civic buildings and even the Great Pyramid of Giza are all built from limestone. However, limestone is easily attacked by acid rain, meaning that as pollution levels rise these buildings have been subjected to greater levels of erosion.