Geology is the study of the structure and the origin of the planet earth through understanding the formation of its rocks, minerals, fossils and soils. Through studying the fossil record we can also learn and understand more about ancient life. Some geological formations or sites may be the only place this series of events, or fossil record, are captured, so it is often very important to preserve these as a record.
The Mendip Hills are noted for their geodiversity, with a large range of rock types ranging from Devonian to Jurassic exposed in many natural rock outcrops and quarries. The AONB has 7 nationally designated geological and 8 mixed interest (geological and biological) SSSIs and 18 Local Geological Sites reflecting the importance of the geological interest. These include natural features of exposed rocks, dry gorges, sink holes, areas of sunken ground and cave systems of the classic Carboniferous Limestone karst landscape to sandstone peaks and a long history of quarrying and mining which ties it closely to the history and culture of the area.