Heavitree stone is a type of

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

stone, red in colour, of very coarse texture and prone to weathering, which occurs naturally in the parish of

Heavitree Heavitree is a historic village and former civil parish situated formerly outside the walls of the City of Exeter in Devon, England, and is today an eastern district of that city. It was formerly the first significant village outside the city o ...

near the

City of Exeter A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agree ...

Devon Devon ( ; historically also known as Devonshire , ) is a ceremonial county in South West England. It is bordered by the Bristol Channel to the north, Somerset and Dorset to the east, the English Channel to the south, and Cornwall to the west ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. It was quarried in the area from about 1350 to the 19th century, and was used to construct many of Exeter's older buildings, including Exeter Castle, the old city walls, and many of the

almshouses An almshouse (also known as a bede-house, poorhouse, or hospital) is charitable organization, charitable public housing, housing provided to people in a particular community, especially during the Middle Ages. They were often built for the povert ...

and parish churches. Many ancient buildings in Exeter made of Heavitree stone were destroyed by enemy bombing during

World War II 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 was first referred to by Sir

Henry De La Beche Sir Henry Thomas De la Beche KCB, FRS (10 February 179613 April 1855) was an English geologist and palaeontologist, the first director of the Geological Survey of Great Britain, who helped pioneer early geological survey methods. He was the ...

in 1839, as the "Conglomerates of Heavitree".

Quarries

The site of the historic

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 ...

is represented today by "Quarry Lane" in Heavitree, where survive two quarry faces,One on Quarry Lane itself, another "at the eastern end of a grassed playing area off Coates Road, Quarry Lane" and another quarry existed in nearby Wonford. A quarry is first recorded in 1390.

Description

The stone comprises angular fragments and grains, up to 40mm in diameter, of

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

, minerals,

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

and

volcanic rock Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...

s, all embedded in a

matrix Matrix (: matrices or matrixes) or MATRIX may refer to: Science and mathematics * Matrix (mathematics), a rectangular array of numbers, symbols or expressions * Matrix (logic), part of a formula in prenex normal form * Matrix (biology), the m ...

of finer

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

s and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

. As the stone was formed from sediment laid down by flash flooding in semi-arid conditions, the stone fragments are not rounded by the wearing of water, as are sedimentary deposits laid down in the sea. It dates to the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

period, about 280 million years ago.

Quarries

Description

References

Further reading