In the 10 years ending in 2010, 2.5 billion tonnes of aggregates were consumed by the UK. These aggregates were supplied from various, and to the layman perhaps surprising, sources.
Land based - the largest source is from quarrying of the land for sand and gravel, or for rock suitable for crushing (mainly limestone, sandstone, and igneous rock but also some unusually hard occurrences of chalk, ironstone, slate etc);
Marine – sand and gravel is also dredged from the seabed and is a regionally significant source;
Recycled and by products – a wide variety of construction wastes and industrial by-products make a major contribution to supply. These include construction, demolition and excavation wastes; slags and ashes; and mineral wastes;
Specialist – small amounts of certain lightweight and high density aggregates are manufactured for specialist purposes; and
Imported – the balance of supply consist of imported material (mainly as crushed rock or value-added products) principally from elsewhere in the UK and Norway.