Limestone hills, Cotswolds

Image to left: oolitic limestone close up

The Cotswold hills are made of Oolitic limestone, a type of limestone made up of small round grains. These formed in shallow, warm waters like those found today around Florida and parts of the Caribbean Sea, where calcium carbonate is deposited from sea water due to evaporation. The round grains grow in size as they are gently rolled to and fro by waves, in water only a few metres deep.

Cotswold stone is used as a building stone because it easily splits into blocks and is quite weather-resistant. Its pale golden colour helps to make Cotswold villages very attractive to tourists.