Purbeck Marble is a

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

iferous

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

found in the Isle of Purbeck, a

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on a ...

in south-east

Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , ...

, England. It is a variety of Purbeck stone that has been

quarried A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...

since at least Roman times as a decorative building stone.

Geology

Stratigraphically these limestone beds lie towards the top of the

Durlston Formation The Durlston Formation is a geologic formation in England. Particularly in the Isle of Purbeck. It preserves fossils dating back to the Berriasian stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of ...

of the Purbeck Group. They were deposited during the

Berriasian In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ag ...

age of the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145& ...

epoch. Purbeck Marble is not a

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

, like a true

marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphose ...

, but is so-called because it can take a fine polish. Its characteristic appearance comes from densely packed shells of the freshwater snail ''

Viviparus ''Viviparus'', common name the river snails, is a genus of large, freshwater snails with an operculum, aquatic gastropod mollusks.Bouchet, P. (2014). Viviparus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.ma ...

''. Sussex Marble is similar in type. The 'marble' is properly

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

as a biomicrudite, as it consists of large clasts (the snail shells) in a fine-grained limestone mud matrix. The individual marble beds (also known as 'seams'), lie between layers of softer marine clays and mudstone, laid down during repeated marine ingressions. Some of the beds contain iron oxide/hydroxide minerals, such as

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

or limonite, giving red or brown varieties, while other beds contain glauconite giving a green (or occasionally blue) colour.

Occurrence

Purbeck Marble is found at outcrop, or beneath superficial cover, all the way across the Isle of Purbeck from Worbarrow Tout in the west to Peveril Point in the east. The marble beds are never more than 1.2 m thick and are often much thinner. The outcrops lie within the Purbeck Monocline, with the beds dipping moderately steeply to the north.

Use

There is a single example of Purbeck Marble being used during the

Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...

, in a cist at Langton Matravers. During the Romano-British period, Purbeck Marble was used for inscriptions, architectural mouldings and veneers, mortars and pestles, and other articles. Purbeck Marble was also quarried in

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

times and can be seen in virtually all the cathedrals of the south of England, in columns and slab panels and flooring. For example, it is used in

Exeter Exeter () is a city in Devon, South West England. It is situated on the River Exe, approximately northeast of Plymouth and southwest of Bristol. In Roman Britain, Exeter was established as the base of Legio II Augusta under the personal comm ...

, Ely,

Norwich Norwich () is a cathedral city and district of Norfolk, England, of which it is the county town. Norwich is by the River Wensum, about north-east of London, north of Ipswich and east of Peterborough. As the seat of the Episcopal see, See of ...

Chichester Chichester () is a cathedral city and civil parish in West Sussex, England.OS Explorer map 120: Chichester, South Harting and Selsey Scale: 1:25 000. Publisher:Ordnance Survey – Southampton B2 edition. Publishing Date:2009. It is the only ...

Salisbury Salisbury ( ) is a cathedral city in Wiltshire, England with a population of 41,820, at the confluence of the rivers Avon, Nadder and Bourne. The city is approximately from Southampton and from Bath. Salisbury is in the southeast of ...

, Lincoln, Llandaff,

Southwark Southwark ( ) is a district of Central London situated on the south bank of the River Thames, forming the north-western part of the wider modern London Borough of Southwark. The district, which is the oldest part of South London, developed ...

and Canterbury Cathedrals, and in

Westminster Abbey Westminster Abbey, formally titled the Collegiate Church of Saint Peter at Westminster, is an historic, mainly Gothic church in the City of Westminster, London, England, just to the west of the Palace of Westminster. It is one of the United ...

. Additionally, it was utilised in the 13th-century King's Table, a furnishing used in coronation events. It has been less used in modern times, but a remarkable example is the church at Kingston, Purbeck, Dorset built in 1874–1880. Other

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

of Purbeck Limestone are being quarried at the present time (2021). Purbeck Marble was previously extracted in 1993.Haysom, Treleven (1998), "Extracting Purbeck Marble", ''Hatcher Review'', 5(45), 48–54. Purbeck Marble is used by a number of contemporary sculptors, such as Robbie Schneider, and Emily Young. File:Temple church 906.jpg, Interlaced semicircular arches supported by Purbeck Marble shafts in the

Temple Church The Temple Church is a Royal peculiar church in the City of London located between Fleet Street and the River Thames, built by the Knights Templar as their English headquarters. It was consecrated on 10 February 1185 by Patriarch Heraclius of J ...

, London File:Beverley minster 014.JPG, The 13th-century south transept of Beverley Minster, richly decorated with Purbeck Marble shafts.

References

External links

{{Commons category, Purbeck Marble
Geology of the Wessex Coast

Langton Matravers Local History and Preservation Society, including Museum of the Purbeck stone industry

Salisbury Cathedral

Purbeck stone company website
Building stone Geology of Dorset Isle of Purbeck Limestone