Cliffs of magnesian limestone, Grangetown promenade - geograph

Cellular patterns in boulder of magnesian limestone - geograph

The Magnesian Limestone is a suite of

carbonate rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolosto ...

s in north-east

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

dating from the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

period. The outcrop stretches from

Nottingham Nottingham ( , locally ) is a city and unitary authority area in Nottinghamshire, East Midlands, England. It is located north-west of London, south-east of Sheffield and north-east of Birmingham. Nottingham has links to the legend of Robi ...

northwards through

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...

and into

County Durham County Durham ( ), officially simply Durham,UK General Acts 1997 c. 23Lieutenancies Act 1997 Schedule 1(3). From legislation.gov.uk, retrieved 6 April 2022. is a ceremonial county in North East England.North East Assembly �About North East E ...

where it is exposed along the coast between

Hartlepool Hartlepool () is a seaside and port town in County Durham, England. It is the largest settlement and administrative centre of the Borough of Hartlepool. With an estimated population of 90,123, it is the second-largest settlement in County D ...

and

South Shields South Shields () is a coastal town in South Tyneside, Tyne and Wear, England. It is on the south bank of the mouth of the River Tyne. Historically, it was known in Roman times as Arbeia, and as Caer Urfa by Early Middle Ages. According to the 20 ...

. The term has now been discontinued in formal use though it appears widely in popular and scientific literature on the geology of northern England. The Magnesian Limestone is now incorporated within the

Zechstein Group The Zechstein ( German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Middle to Late Permian (Guadalupian to Lopingian) age located in the European Permian Basin which stretches from the east coast of Engla ...

. In the southern part of its outcrop, the former 'Lower Magnesian Limestone' is now referred to as the '

Cadeby Formation Cadeby may refer to: * Cadeby, Leicestershire, England * Cadeby, Lincolnshire, England * Cadeby, South Yorkshire Cadeby is a village and civil parish in the Metropolitan Borough of Doncaster in South Yorkshire, England. The population at the ...

'. Overlying this it is the 'Edlington Formation' (formerly the '

Middle Permian The Guadalupian is the second and middle series/ epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± ...

Marl') and above this the Brotherton Formation (formerly the 'Upper Magnesian Limestone'). In the north, the Lower Magnesian Limestone is now referred to as the Raisby Formation and the middle Magnesian Limestone as the Ford Formation. The Upper Magnesian Limestone is replaced by the Roker Formation (in its lower part) and the Seaham Formation (in its upper part) with the Edlington formation between them, though in the Durham area this last is replaced by the Fordham Evaporite Formation and the Seaham Residue. Much of the Magnesian Limestone is

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

, i.e. calcium magnesium carbonate, and has been for many years the main source of dolomite-rock in Britain. It is used in connection with the production of

refractory brick In materials science, a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, ...

s but also for aggregate for road-building and other construction purposes. It is also used in the production of agricultural lime. This type of limestone was used for statues in antiquity because of its resistance to acid. Many pieces of dolomite were found in the ruins of Rome, though they are thought to have been brought from Magnesia in Greece.

References

{{reflist Permian System of Europe Geology of England