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), dolomite rock (also kn ...

s in north-east

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 ...

dating from the

Permian The Permian ( ) is a geologic period and System (stratigraphy), 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 251.902 Mya. It is the s ...

period. The outcrop stretches from

Nottingham Nottingham ( , East Midlands English, locally ) is a City status in the United Kingdom, city and Unitary authorities of England, unitary authority area in Nottinghamshire, East Midlands, England. It is located south-east of Sheffield and nor ...

northwards through

Yorkshire Yorkshire ( ) is an area of Northern England which was History of Yorkshire, historically a county. Despite no longer being used for administration, Yorkshire retains a strong regional identity. The county was named after its county town, the ...

and into

County Durham County Durham, officially simply Durham, is a ceremonial county in North East England.UK General Acts 1997 c. 23Lieutenancies Act 1997 Schedule 1(3). From legislation.gov.uk, retrieved 6 April 2022. The county borders Northumberland and Tyne an ...

where it is exposed along the coast between

Hartlepool Hartlepool ( ) is a seaside resort, seaside and port town in County Durham, England. It is governed by a unitary authority borough Borough of Hartlepool, named after the town. The borough is part of the devolved Tees Valley area with an estimat ...

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. The town was once known in Roman Britain, Roman times as ''Arbeia'' and as ''Caer Urfa'' by the Early Middle Ag ...

. 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. In the southern part of its outcrop, the former 'Lower Magnesian Limestone' is now referred to as the ' Cadeby Formation'. 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 ± 0. ...

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, 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 bricks 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