In Britain, there are three different rock types:
- Igneous (pronounced ig-knee-us)
- Metamorphic (met-a-more-fic)
- Sedimentary (sed-ee-ment-ary)
There are large deposits (quantities) of sedimentary rock such as limestone in all parts of the country. At Quarryville we also excavate some igneous rocks, though this is not typical in Britain.
The soil forms in layers.
The dark topsoil is full of rich humus (rotting organic matter). In the layer below it, called the subsoil, the humus is mixed with tiny stones and sand. It’s lighter in colour than the topsoil and far less fertile. The lower layers contain larger stones broken off the rocks below.
Sand and gravel quarries can be very deep, but rock quarries are generally deeper and are dug on several different levels called “benches”.
The first stage of the excavation is a carefully controlled explosion that breaks the rock up into large lumps. A large truck or conveyor then takes this raw material to a powerful crusher where the rocks are broken down into smaller pieces and separated into different sizes.
Due to its hardness and strength, it’s used for the foundation work for all types of construction - houses, factories, offices, schools and hospitals.
It can be processed into different sizes and used as road surfaces, footpaths, playgrounds and car parks. It’s also used in the manufacture of cement, iron and steel, medicines, plastics, cosmetics, paint, sugar, glass, paper and bread.
Most crushed rock is used within 30 miles of where it’s extracted. The aggregates are then delivered to customers by lorry (90%), by rail (5%) and by sea (5%). Quarryville’s Rock Quarry supplies nearby towns like Quarrington, Rocksford, Stoneyhenge and Boulder City.
Aggregate is the technical name we use for crushed rock that has been broken into small pieces, either by nature (sand and gravel) or by people. We use around 200 million tonnes of aggregates every year in Britain, most of it for building.