Halecombe is a

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

quarry A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some juri ...

near Leigh-on-Mendip on the

Mendip Hills The Mendip Hills (commonly called the Mendips) is a range of limestone hills to the south of Bristol and Bath, Somerset, Bath in Somerset, England. Running from Weston-super-Mare and the Bristol Channel in the west to the River Frome, Somerset ...

Somerset Somerset ( , ), Archaism, archaically Somersetshire ( , , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by the Bristol Channel, Gloucestershire, and Bristol to the north, Wiltshire to the east ...

, England. The quarry exhibits pale to dark grey well-bedded

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

Limestone, about 350-320 million years old, dipping steeply and consistently northwards and numerous "fist-sized"

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

inclusions within the limestones both solid and hollow with internal calcite

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

growth. There are abundant near-vertical

fissures A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure A ...

and joints in the limestone with varying amounts of calcite mineralization and

tufa Tufa is a variety of limestone formed when carbonate minerals precipitation (chemistry), precipitate out of water in ambient temperature, unheated rivers or lakes. hot spring, Geothermally heated hot springs sometimes produce similar (but less ...

growth around groundwater seepages. There are abundant shelly fossils and corals. Quarrying activity was initiated at Halecombe at the time of the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. It had been worked under private ownership until purchased by Hobbs in the 1960s; subsequently worked by Wimpey Hobbs following their amalgamation in the early 1980s and by Tarmac Ltd from 1996. It is now owned by Anglo American. The landscape provides several areas identified under the UK Biodiversity Action Plan including Lowland Meadow, Limestone Grassland and Species-rich Neutral Grassland. The site is subject to its own Biodiversity Action Plan. Pans submitted in December 2011 provide for the provision of a water balancing lake.

References

See also