Colemans Quarry, is a limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 quarry

Quarry

A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often collocated with concrete and asphalt plants due to the requirement...

 at Holwell, near Nunney

Nunney

Nunney is a village and civil parish near Frome in the Mendip local government district within the English county of Somerset. The parish includes the hamlet of Holwell.The name of the village comes from Old English and means Nunna's island....

 on the Mendip Hills

Mendip Hills

The Mendip Hills is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running east to west between Weston-super-Mare and Frome, the hills overlook the Somerset Levels to the south and the Avon Valley to the north...

, Somerset

Somerset

The ceremonial and non-metropolitan county of Somerset in South West England borders Bristol and Gloucestershire to the north, Wiltshire to the east, Dorset to the south-east, and Devon to the south-west. It is partly bounded to the north and west by the Bristol Channel and the estuary of the...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

The Colemans Quarry complex comprises four pits separated by three roads (including the A361)

The quarry exhibits pale to dark grey Black Rock, Vallis and Clifton Down Groups of Carboniferous

Carboniferous

The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 Limestone with overlying buff-coloured Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 oolitic

Oolite

Oolite is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Hellenic word òoion for egg. Strictly, oolites consist of ooids of diameter 0.25–2 mm; rocks composed of ooids larger than 2 mm are called pisolites...

 limestone forming an angular unconformity

Unconformity

An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...

. The ancient Jurassic erosion surface at the unconformity contains oyster

Oyster

The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....

 shells and abundant marine borings in the top of the Carboniferous Limestone. There are near-vertical fissures and joints in the limestone with varying amounts of calcite

Calcite

Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

 mineralization. A few of these have been found to contain rare Upper Triassic and Jurassic vertebrate remains. There are abundant shelly fossils and corals.

It came to fame in 1858 when a geologist named Moore purchased three tons of fissure filling, and then spent 3 years sifting and sorting and separated more than one million fossils including 27 small mammal teeth.

Minerals found at the site include Calcite, Goethite

Goethite

Goethite , named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low-temperature environments. Goethite has been well known since prehistoric times for its use as a pigment. Evidence has been found of its use in paint pigment samples...

, Purple Fluorite

Fluorite

Fluorite is a halide mineral composed of calcium fluoride, CaF2. It is an isometric mineral with a cubic habit, though octahedral and more complex isometric forms are not uncommon...

, Baryte, Galena

Galena

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...

, Rhodochrosite

Rhodochrosite

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. The streak is white. Its Mohs hardness varies between 3.5 and 4. Its specific gravity is 3.5 to 3.7. It...

 and Manganese

Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

 minerals.

External links

• Mineral data for this quarry from mindat.org

See also

• Quarries of the Mendip Hills
  Quarries of the Mendip Hills
  The Mendip Hills are the most southerly Carboniferous Limestone Upland in Britain and are found in northern Somerset.They are composed of three major anticlinal structures, each with a core of older Devonian sandstone and Silurian volcanic rocks...