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Strategic Stone Study A Building Stone Atlas of

First published by English Heritage February 2012 Rebranded by Historic December 2017 Introduction

No one can fail to be impressed by the natural scenic beauty of This glacial legacy is evident across most of the lower ground this county when seen from its hilltops. Much of this stunning of the county with the presence of till and outwash sand and scenery is a direct result of its varied, underlying geological mainly of Devensian age. The dominant features succession. The hills of Worcestershire rise on three sides however, are the great spreads of drift made up of fluvial sands, neatly enveloping the vale of the and its and alluvium. These terraces, rise step-like up the valley tributaries and leaving only the south as an opening to the sides with each rise taking us further back into periods of Channel. In the west the form the border torrential meltwaters as the climate warmed. Locally, within with . Stretching for 12 kilometres, they dominate this natural landscape a very distinctive man-made vista has the skyline and include some of the oldest rocks in England, been added, in particular where the rocks have been the consisting of and diorites of age. This principal source of building stones. influential geological structure, known as the Malvern Axis, continues northwards as the tightly folded sedimentary and shales of the and Hills with their distinctive ridge and vale topography.

In the north of the county there are younger rocks of the Coalfield with its hard together with mudstones and thin coal seams. The high ground continues eastwards into the and Hills where Carboniferous and sandstones and mudstones and coarse breccias crop out and at Lickey sit juxtaposed against hard resistant quartzites. As the borders with are approached, to the south of the Arden escarpment, a more resistant component within the Triassic mudstones that underlie much of central Worcestershire, forms a line of higher ground known as the Ridgeway which is eventually masked by glacial deposits.

Finally rising into can be seen the limestones of the impressive Cotswold Escarpment. Only a small part of the falls within the county but the isolated Jurassic outlier of Hill, imposing and slab like, stands sentinel above the valley of the River Avon. Most of the lower ground in the northern part of the county is underlain by the distinctive red sandstones of Permian and Triassic age, some of which are resistant enough to form prominent ridges. To the south and east these sandstones change to the mudstones of the Triassic and Jurassic periods which being much softer, form the broad sweeping vale of the River Severn. Further small escarpments mark out the Arden Sandstone outcrop as well as the limestones of the which all wind southwards to the Severn Estuary. These are incorporated into the Worcester plain which has been shaped by the Severn, Teme, Stour and Avon rivers and the meltwaters from the vast Pleistocene ice sheets that poured from the north and west some 15,000 years ago.

XXX Strategic Stone Study 1 Worcestershire Bedrock Geology Map

Derived from BGS digital geological mapping at 1:625,000 scale, British Geological Survey ©NERC. All rights reserved

Worcestershire Strategic Stone Study 2 Precambrian

The Precambrian rocks of the Malvern Hills are divided into the Malverns Complex and the overlying Warren House Formation. The former is a suite of predominantly igneous rocks mainly diorites, tonalites and granites but with some ultra basic material and a variety of metamorphic rocks. It also includes dykes and veins of microdiorite and pegmatite. The Malvern Hills provide one of the largest exposures of Precambrian rocks in England.

Malverns Complex railway station drinking trough. Malvern Stone These hard rocks were used locally as a building stone although they were subsequently quarried predominantly as This distinctive building stone style is ubiquitous in the area an aggregate for roadstone use. Quarrying ended in the area in and provides a local character all of its own which is also to be the 1970s but many of the large scars can still be seen and found in towns and villages a few miles away from the Malvern have become a paradise for the research geologist. Many Hills, in buildings and boundary walls (Welland, ). houses, churches and walls in Great Malvern, Malvern Wells Primary School (below), built and , are constructed with the pink, coarse in 1885, is an eclectic mix of styles with rubble walls of Malvern grained blocks, contrasting with the finer grained, grey Stone and Cotswold Stone dressings. Adjacent cottages also of diorite blocks, providing excellent examples of the use of these Malvern Stone. stones.The irregular, natural jointing within the rock has resulted in irregular shapes to the building stones and thus Warren House Formation gives a very distinctive polygonal pattern to the constructions. The Great Malvern railway station drinking trough (top) in Seen on Broad Down and Hangman’s Hill, this formation is Sandstone has an arch of Cotswold Stone and red composed of volcanic rocks which consist of lavas of basalt Sandstone all set in a wall of Malvern Stone. Great and rhyolite interbedded with pyroclastic ash flows. Pillow Malvern railway station was built in 1860/62 and is a fine lavas at nearby Clutter’s Cave suggest submarine volcanic example of the style and use of Malvern Stone. eruptions. Not much use has been made of the rocks of this formation as building stone save for incorporation into some local walls.

Sedimentary Cambrian strata are exposed in the southern parts of the Malvern Hills where the Malvern Quartzite and Hollybush Sandstone formations can be seen in restricted exposures. Very little use has been made of the stones from these formations except locally for use as aggregates and boundary walling.

Malvern Wells Church of England Primary School Worcestershire Strategic Stone Study 3 Ordovician Lickey Quartzite Formation

The only Ordovician rock to have been used as a building stone is the Lickey Quartzite: a sedimentary rock deposited in a high energy marine environment and showing variations in colour from purple to white. This hard siliceous rock has been used in this north-eastern corner of the county around and Lickey for rough and boundary walling but was quarried predominantly as a source of aggregate. Silurian

The restricted outcrops of Cambrian and Ordovician strata All Saints church, , on the slopes of the Abberley Hills. contrast significantly with the very extensive exposures of Silurian rocks. The latter stretch from the northern end of the Precambrian Malvern Hills into the Suckley Hills and Formation northwards to the Abberley Hills. All four divisions of the Silurian are represented; Llandovery, Wenlock, and ‘Wenlock Limestone’ the Pridoli . Of all the Silurian limestones it is the Wenlock Limestone that was most commonly used as a building stone. Subsequently LLANDOVERY SERIES quarried largely as an aggregate and for burning, it was May Hill Sandstone used in earlier times in local cottages and as a walling-stone. Where is has been used it varies from calcareous mudstones Cowleigh Park Formation and siltstones (which weather quite badly) to hard spar- cemented shelly limestones with more porcellanous beds. The Llandovery Series has at its base the Cowleigh Park It can be seen occasionally as a building stone in cottages, Formation which was exploited on a small scale for its farm buildings and boundary walls along the Silurian outcrop sandstone for building purposes in the Suckley area. stretching from to Abberley in the western part of the county. The boundary wall is made of Silurian limestones and WENLOCK SERIES siltstones. The church itself has St Maughans Formation sandstones forming the nave and Bromsgrove Sandstone A journey through the villages of these peaceful hills will throw forming the 14th-century tower. up examples of cottages built from the harder, purer, grey limestones of the Woolhope, Much Wenlock and Aymestry PRIDOLI SERIES formations from a whole series of ranging in size from small pits to the now disused major excavations of Penny Hill, Downton Sandstone Formation Whitmans Hill, Woodbury (which ceased operations in 2000) and Shavers End. Careful investigation of the garden walls will This Formation marks the top of the Ludlow Series. Although reveal a wealth of . Trilobites, corals, crinoids, used as a building stone just over the border in Herefordshire brachiopods, gastropods and bryozoans – all are there it does not have a significant outcrop in Worcestershire. in abundance.

Worcestershire Strategic Stone Study 4 Raglan Mudstone Formation Carboniferous

The upper part of the Silurian marks a change from marine to The higher horizons of the Carboniferous period can be seen in terrestrial conditions and is made up of the fluvial deposits of the Wyre Forest Coalfield where the Coal Measures Group and the Raglan Mudstone Formation, which, with its chocolate red the overlying Warwickshire Group crop out. It is predominantly colour, is in great contrast to the grey and beige colouring of the Etruria, and Salop formations of the the underlying limestones and shales just described. Warwickshire Group, forming the southern portion of the coalfield, that are to be found in Worcestershire. The sandstones of the Halesowen and Salop formations have been used to great effect with much evidence of their former The Raglan Mudstone Formation and the overlying St extraction still to be seen in the old quarries of the coalfield Maughans Formation surround the valley of the and alongside the River Severn especially near the county upstream from to . The near boundary with . horizontal strata make a significant scarp slope on the western banks of the River Teme. In the same locality the junction between the Raglan Mudstone and St Maughans Formations is marked by the Bishop’s Frome Limestone Member (formerly Psammasteous Limestone). The latter is only a few metres thick at best and was used for lime burning and as a roadstone, but was also used for fonts and decorative work. This beautiful countryside yields this building stone, especially seen in the churches along the valley and on the higher ground to the west.

Lower Red Sandstone Group

St Maughans Formation (formerly Ditton Series)

This formation consists of red-brown, grey and greenish-grey sandstones, mudstones and conglomerates, and underlie the extensive plateau at Bromyard to the west of the River Teme. Chocolate brown, green and grey sandstones of the St Maughans Formation The church at Shelsley Beauchamp is indeed a treasure trove in the St Kenelm’s church at Clifton on because not only can the great variety of these sandstones be Teme. The window surround is of tufa. seen in the outside walls of the nave, but as the site is at the foot of the Abberley Hills the boundary walls are built of grey fossiliferous Silurian limestones and siltstones. Many of the sandstones have been used as a building stone and they can be seen in their many colours in the church and cottages at and surrounding villages.

Cottage in Clifton upon Teme, constructed in sandstones rubble run to course of the St Maughans Formation. Worcestershire Strategic Stone Study 5 Holy Trinity church, Far Forest.

Warwickshire Group

Etruria Formation (formerly Etruria Marl)

In the area of north-west and beyond towards in Shropshire, many thin sandstones have been used for walls of local cottages and for boundary walls. The strata is typically red, purple, grey and mottled clays but with frequent but impersistent thicker beds of brown sandstones. Sometimes conglomerates and breccias are also present. All are significant building stones in the village of Far Forest and in the isolated cottages of the Wyre Forest.

The old school and schoolhouse in Far Forest (right) has coursed random rubble walls of brown sandstone from the Etruria Formation of the Carboniferous. The Holy Trinity church (above), built in 1843/4, also in Far Forest, shows coursed rubble walls and buttresses of Etruria Formation sandstones. The old schoolhouse in Far Forest. Worcestershire Strategic Stone Study 6 Halesowen Formation

Highley Sandstone & Thick Sandstone The best known building stone from the Halesowen Formation is the massive light brown rock that in the and Abberley areas reaches 30m thick. Known as the Highley Sandstone (or Thick Sandstone) it has been used in the building of the churches and cottages in Mamble, and Abberley. In these locations the rock is massive, grey and brown in colour and frequently displays oxide (geothite) staining on the joint surfaces and Liesgang rings within the rock. The rock is best known as Highley Sandstone which has been famously quarried alongside the River Severn just over the county boundary in Shropshire. It was used in considerable quantities in the construction of and is typically a greenish-grey sandstone occasionally with conglomeratic horizons. Although the thicker beds are hard at outcrop, it is a stone that weathers poorly and is constantly being replaced at the Cathedral by a much harder sandstone of similar colour, also of Carboniferous age, from the Forest of Dean.

Highley Sandstone has been used in the construction of other churches along the River Severn such as the tower of St Anne’s in Bewdley, built 1695-6 (right) and also for bridges. These are probably part of the original three-arched stone bridge by Pritchard in 1775. Other bridges across the River and the Railway are constructed of this stone.

The tower of St Anne’s in Bewdley.

Ashlar construction of abutment arches of Stourport-on-Severn road-bridge.

Worcestershire Strategic Stone Study 7 Arley Castle.

It is to be found in many churches where they are located close to the Rivers Severn or Teme. The Guildhall entrance in Bewdley is a good example of the use of the stone and its weathering characteristics. The Highley Sandstone (Thick Sandstone) can be seen in St Mary’s church, Abberley (left), built in 1850/52 and rebuilt in 1876 after a fire; and its clock tower ; and its lateral equivalent was used as the main building stone of the now demolished Arley Castle.

Arley Castle (above) was built in 1843/4 and the majority of it was demolished in 1962/3. The Barbican is made of the local buff coloured sandstone equivalent of Highley Sandstone.

St Mary’s church, Abberley. Worcestershire Strategic Stone Study 8 Salop Formation MEMBER

Alveley Stone or Hexton’s Stone In general this is a fine-grained well sorted sandstone with common cross-bedding. For many centuries Hexton’s just north of Arley supplied red and grey sandstone to many locations along the River Severn, such as Hafren House, Arley (left).

Blocks of cut rock can still be seen abandoned alongside the remains of a wharf on the east bank of the river (below). The rock was transported down river and used in Worcester Hafren House in Arley constructed Cathedral and in the construction of the quayside at Arley of ashlared Alveley Stone from the nearby quarry. (left). Indeed it can be seen to great effect in the village of Arley, in dwellings, boundary walls and the quayside. It is the principal stone used in St Peter’s church at Arley, All Saints, Wribbenhall and St Martin’s Worcester. Permo-Triassic

All the sedimentary rocks of the Permo-Triassic have a major impact on the topography and buildings of a vast swathe of the central and north-eastern parts of the county. These strata stretch from the Abberley and Malvern Hills in the west to the edge of the south coalfield, the Plateau in the north and to the Lickey and in the northeast; they pass eastwards into Warwickshire where they continue to be significant, abut the lower Jurassic rocks and Cotswold Hills to the east and south east and then spread down the Severn Valley towards .

The quayside at Arley.

Blocks of cut rock abandoned alongside the remains of a wharf on the east bank of the river Severn. Worcestershire Strategic Stone Study 9 The railway viaduct in Bewdley, formed of Sandstone.

Permian

The Permian rocks of the county are present as the Clent Formation (formerly Clent or Haffield Breccia) and the Bridgnorth Sandstone Formation (formerly Lower Mottled Sandstone).

Warwickshire Group

Clent Formation

Clent Breccia The breccia is reddish coloured with subangular fragments mainly of volcanic origin set in a mudstone matrix. Formed as A coursed rubble boundary wall in alluvial fans at the base of the rising mountains of the Variscan Bewdley, made of Bridgnorth Sandstone. Orogeny, the rock can be seen capping the Abberley Hills (where it is known as the Haffield Breccia), at Osebury Rock (a Good examples can be seen in Bewdley adjacent to the riverside cliff on the Teme) and in the type area of the Clent Hills. outcrop. In the town, the bridge carrying the is partly constructed of steeply cross-bedded Bridgnorth Sandstone Formation Bridgnorth Sandstone and cave dwellings are present in the (formerly Lower Mottled Sandstone) sandstone in the nearby ancient river cliff of Blackstone Rock. The railway viaduct (above) also in Bewdley, is formed of large Bridgnorth Sandstone blocks of Bridgnorth Sandstone probably quarried locally. The These dark red, dune bedded sandstones outcrop between railway opened in 1862. Bewdley and and extend northwards into Staffordshire. The rock is generally quite soft and does not make a good building stone but it has been used in boundary walls and doorsteps. Worcestershire Strategic Stone Study 10 Triassic

Overlying the Permian rocks is a sequence of fluvial deposits that form the Sherwood Sandstone Group. The group comprises the Kidderminster Formation (formerly Pebble Beds), the Wildmoor Sandstone Formation (formerly Upper Mottled Sandstone) and the Bromsgrove Sandstone Formation (formerly Lower Sandstone), all consisting of red-brown sandstones and conglomerates. Cave dwellings exist in the Wildmoor Sandstone at Redstone Rock in Stourport-on-Severn and in the Kidderminster Formation in Kidderminster.

Kidderminster Formation

The conglomerates of the Kidderminster Formation are resistant enough to form a significant ridge running through The church of All Saints, Bromsgrove, a Victorian building of 1872. Kidderminster and the high ground northeast of Bromsgrove rising further towards the Clent Hills. Occasional local use has been made of sandstones from this formation for buildings Hall. Boundary walls in the Kidderminster and but it is weakly cemented and has been used predominantly Bromsgrove areas are ubiquitous. Impressive use is also made as a source of sand and gravel. The large liver coloured of the stone in villages such as and . quartzite pebbles of the conglomerates have been reworked Some of the best quality Bromsgrove Sandstone came from by the rivers flowing southwards at the end of the Pleistocene quarries not only in Bromsgrove but also in the and today can often be seen in some of the old street area where some beds provided pink, cream and a grey-white, pavements across central Worcestershire. hard building stone, put to great use in many parts of the county. It was quarried alongside the River Severn at Ombersley Wildmoor Sandstone Formation and was used in the construction of Stourport Canal Basin and is yet another stone used in Worcester Cathedral. This sandstone is also generally weakly cemented and soft, its main use has been and still is as a moulding sand. However it Mudstone Group does appear to have been used locally in boundary walls. For much of the latter part of the Triassic period sedimentation Bromsgrove Sandstone Formation was characterised by the deposition of the mudstone, siltstone, evaporite and occasional sandstone beds that form Bromsgrove Sandstone (Hadley Stone, Holt the Mercia Mudstone Group (formerly Keuper Marl). These Stone, Ombersley Stone & Stone) beds represent the deposition of water and wind borne For building purposes this is the most widely used stone materials laid down in the shallow low energy sub-aqueous quarried from the red Sherwood Sandstone Group. Although environments of an arid coastal plain. The salt deposits found no quarries now operate it has been extensively used for in the group at Droitwich also provide further evidence of churches, public buildings, cottages and boundary walls. these arid environments. Within the Mercia Mudstone Group Some notable examples are the parish churches at occurs the locally important building sandstone unit, the Bromsgrove and Tardebigge, Castle and parts of Arden Sandstone Formation. Worcestershire Strategic Stone Study 11 The village of Broadway.

Arden Sandstone Formation The predominantly comprise grey fossiliferous mudstones, sandstones and limestones which distinguish it Arden Sandstone, including Stone & from the earlier Triassic rocks. The boundary forms a Stone prominent north-south escarpment east of the River Severn. This formation consists of mudstones, siltstones and grey- green to pale grey, fine to coarse grained and cross-bedded Jurassic sandstones. Large clasts of softer mudstone are occasionally present. The formation varies in thickness from less than a Jurassic strata are confined to the eastern and south eastern metre in the area to the east of Droitwich to 5m just east of parts of the county and they are represented by the Lias and Worcester to 7m in the south west of the county. None of the the groups. These sedimentary successions quarries for this rock in Worcestershire were very large because were deposited in a shallow marine environment and mark suitable beds of sandstone are thin and not laterally extensive. the beginning of a significant period of marine sedimentation. There is a long winding outcrop of the sandstone between Redditch and Worcester with some notable examples of the The is subdivided into five formations with only the use of the stone. The church in Inkberrow is a fine building to Blue Lias and Marlstone Rock formations significant in this inspect and there are walls and cottages in the village built study.. The Inferior Oolite Group within the county is with the same rock. The outcrop continues as an escarpment dominated by ‘typical’ Cotswold limestone lithologies. They to the Gloucestershire border and beyond. The unit reaches have been quarried for building stone, walling stone, lime and 7m thick in the area. The rock has been used in the aggregate and are also a source of many of the famous south of Worcestershire where it can be seen in the churches Cotswold fossils. The unit is thickest in the north Cotswolds (Cookhill) and other village buildings and boundary walls at and thins significantly towards the south. There are a variety of Eldersfield, Pendock and Longdon.Inkberrow, , limestone lithologies within the unit indicating that the nature , , Rous Lench, Stock and Bradley of the marine environment changed repeatedly from current Green, Abberton churches – all built of Inkberrow Stone . Also influenced shoals to lagoons and protected reefs. The higher , and Kingston Cookhill have dressings strata of the Lias Group together with part of the overlying of Inkberrow Stone. Inferior Oolite Group can be seen on . The hill is a geological outlier and it is in the settlements here and in the Penarth Group nearby village of Broadway (above) the full glory of the yellow-brown coloured ooidal limestones can be seen in This thin unit, marking the Triassic – Jurassic boundary nearly all the buildings. represents a regional change from the arid continental environment of the Triassic to the shallow marine shelf seas that characterise the Jurassic. Worcestershire Strategic Stone Study 12 There are many old quarries on Bredon Hill, most of them closely associated with a nearby settlement. Several of these quarries worked the thinner beds of limestone for roofing and boundary walling purposes. All of these types of use can be seen around Bredon Hill and along the adjacent Cotswold escarpment and even some further westwards away from the source itself. The Inferior Oolite Group is divided into the Birdlip Limestone (Lower Inferior Oolite), the Aston Limestone and the Salperton Limestone formations. They are all represented at outcrop east of Broadway. The Birdlip Limestone includes one large building stone quarry just inside the county boundary on Fish Hill, which has now ceased operating. Blue Lias cobbles forming part of the Norman gateway into Abbey. Lower Jurassic Lias Group

Blue Lias Formation

Blue Lias This has at its base the Limestone Member which is up to 8m thick. It forms a small escarpment running from the Gloucestershire border in the south to Redditch in the north where it is known as the Stock Green Limestone. Records show that it was much quarried for lime burning as well as a building and paving stone (right). The thinly bedded grey and brown argillaceous limestones, frequently with thin shelly layers, have Blue Lias used in a boundary wall at been used as building stones usually in villages near to the Worcester Crematorium. outcrop. It can be seen in its many variations, to great effect in the buildings and grounds of Evesham Abbey. The Almonry in Evesham (right), from the 14C, is constructed of coursed rubble Blue Lias and Cotswold limestones, with a Cotswold slate roof. It is also to be seen in many villages such as , Drake’s Broughton and .

RUGBY LIMESTONE MEMBER

This limestone forms the upper part of the Blue Lias Formation. Often referred to as cementstones these are grey muddy limestones which again form a small escarpment just east of the Wilmcote outcrop . There are many small old quarries but there is little surviving evidence of the production of building stones.

The Almonry in Evesham. Worcestershire Strategic Stone Study 13 Middle Jurassic Inferior Oolite Group Birdlip Limestone Formation

Cotswold Stone This limestone dominated formation contains important ‘freestone’ beds, so called because they can easily be cut and shaped for building purposes. They are well bedded, medium The Almshouses at Bredon (1696). to coarse grained ooidal and bioclastic limestones. The higher beds in the succession are of less massive, thinly-bedded, limestones and are typical of the rocks that have been used locally for drystone walling. Within Broadway Quarry excellent exposures of the Cleeve Cloud Member and the Notgrove Member limestones are to be seen. These are the principal freestone beds within the quarry and in surrounding exposures that have contributed to the striking building stones vistas of the Cotswold villages.

These villages include Broadway, Bredon, The Tythe Barn at Bredon constructed using Cotswold limestone from the upper levels of and . However, the stone is also much used some nearby Bredon Hill). considerable distances from its source area and can be widely seen in buildings in Worcester, Evesham, , Malvern, Bewdley and many other towns and villages in the county. In Worcester a few churches are constructed in the limestone and in Malvern area some public buildings are also built of the stone. The limestone is ubiquitous as quoins, gateposts, mullions etc throughout the county where it has often been used in different locations alongside Malvern Stone, Tufa, Triassic sandstones, Blue Lias and Arden Sandstone.

Pebbles from the conglomerates of the Quaternary Kidderminster Formation.

The Quaternary deposits of the county range from Anglian to Marlstone Rock Formation Holocene in age. They include till, glacio-fluvial outwash sands,lacustrine clays, tufa deposits and extensive fluvial Marlstone, Marlstone Rock sands and gravels, as well as landslip and peat deposits. Of Lying near the top of the Lias Group is the Marlstone Rock greatest significance as a building stone, however, are the Formation. This formation which is up to 6m thick, is Holocene limestone tufa which has seen a remarkably represented by a sequence of fossiliferous, grey and brown extensive use around the county. Pebbles from the ferruginous limestones and grey sandy limestones. It forms a conglomerates of the Kidderminster Formation (Triassic) , shelf on the western and northern sides of Bredon Hill and is have been reworked and deposited in the terraces of the River present on the scarp slope at Broadway. It is often covered by Severn and are frequently to be found in the pavements and landslip deposits. A few small quarries provided a local walkways of riverside towns (left). building stone. Worcestershire Strategic Stone Study 14 Holocene Impressive cliffs of tufa are to be seen at Southstone Rock and in the woodlands of the escarpment in locations with spine Tufa chilling names such as Witchery Hole, Hell Hole and As noted previously, the junction between the Raglan Devil’s Dingle. Mudstone and St Maughans formations of the Devonian is marked by the Bishop’s Frome Limestone. This hard, light, porous tufa which can be freely carved has Although only a few metres thick at best, this limestone has been used as a local building stone and can be seen to great played a major part in the formation of a series of Quaternary effect in , Clifton Upon Teme and Eastham limestone tufa deposits (probably formed in the last 10,000 churches as well as in local houses and walls. But its years (Holocene)) that run along the escarpment on the importance is best portrayed in Worcester Cathedral where it western side of the Teme valley. Groundwater percolating has been used in the vaulted ceilings between the ribs (below). through the sandstones of the St Maughans Formation has dissolved out calcium carbonate from the underlying Bishop’s Frome Limestone and then reprecipitated it along a spring line at the contact with the underlying impermeable Raglan Mudstone Formation.

Tufa used at Worcester Cathedral.

Worcestershire Strategic Stone Study 15 Worcester Cathedral.

Imported Stones There are notable examples of the use of white ooidal Portland Stone (Upper Jurassic) in Worcester. It stands out well with its Worcestershire is surrounded by counties which have large bivalve fossils, in the extensive facing of the old police produced a wide range of building stones and many have station (now the College of Technology) and the adjacent Fire been imported for use in the county. Tixall Sandstone from Station. Other interesting constructions include Staffordshire has been used in the construction of the (now HM Prison) at Tardebigge which is made of Worcester bridge and Sandstone from Shropshire is Sandstone (Permo-Triassic) and buildings in , the main building stone of Ombersley Court and church. The Suckley, and Malvern constructed of Cradley Stone (Silurian use of both of these Triassic stones was the result of river and Downton Castle Sandstone). canal transport as was that of both Holt Stone and Highley Sandstone. Repair work to the quayside in Bewdley as part of Dolerite setts and kerbstones are to be found in many recent flood prevention work has included red Permian St locations; the old ones from the easily detected by Bees Sandstone from Cumbria. This now forms part of the their smooth surfaces and rounded corners. Palaeozoic impressive riverside walls alongside the much older sandstones and siltstones are used as and kerbs in constructions of Highley Sandstone, Holt Stone and Alveley many locations and are particularly well represented Stone, has been used in Croome Court, and for in Bewdley. dressings at Chateau Impney. Painswick Stone was used in the construction of Croome Park church. Another replacement And finally reference should be made to the use of smoothly stone used a great deal in repair work at Worcester Cathedral cut grey and brown fine-grained sandstones that are now (above), and parish churches is the Triassic being used in the pavements of many town centres. These red and grey Hollington Stone from Staffordshire. Carboniferous Millstone Grit rocks with their Liesgang patterns are from Crosland Hill in West .

Worcestershire Strategic Stone Study 16 Glossary

Ashlar: Stone masonry comprising blocks with carefully Diorites: A medium to coarse-grained intrusive igneous rock. worked beds and joints, finely jointed (generally under 6 mm) and set in horizontal courses. Stones within each course are of Dolerite: Medium grained basic igneous rock found as small to the same height, though successive courses may be of medium sized intrusions. different heights. ‘Ashlar’ is often wrongly used as a synonym for facing stone. Evaporation: A rock made up of mineral(s) formed by precipitation. Basalt ‘dykes’: A dark, fine-grained, extrusive (volcanic) igneous rock with a low silica content (40% to 50%), but rich in Ferruginous: Containing iron minerals usually in the form of iron, magnesium and calcium. Generally occurs in lava flows, an iron oxide which gives the rock a ‘rusty’ stain. but also as dykes. Basalt makes up most of the ocean floor and is the most abundant volcanic rock in the Earth’s crust. Fossiliferous: Bearing or containing fossils.

Bioclast: Term used to describe fragments of any skeletal Granite: Coarsely crystalline igneous rock, composed primarily material e.g bioclastic limestone, bioclastic sandstone. of quartz, feldspars and micas, with crystal sizes greater than 3 mm. Bivalve: A mollusc with two moveable valves (shells). Geothite: A dark reddish-brown or yellowish-brown mineral Breccia: A sedimentary rock made up of angular fragments of consisting of oxyhydroxide iron, occurring typically as masses rock in a finer-grained matrix. of fibrous crystals.

Buttress: A projection from a wall and bonded to the wall to Igneous: Rocks formed when molten magma cools and create additional strength and support. solidifies. It includes extrusive rocks erupted from volcanoes (e.g. basalt) and intrusive rocks that cool beneath the Earth’s Calcareous: A rock which contains significant (10-50%) surface (e.g. granite, gabbro, granodiorite, dolerite). calcium carbonate principally in the form of a cement or matrix. Interbedded: Occurs when beds (layers or rock) of a particular lithology lie between or alternate with beds of a different Cemented: The materials which bind the grains and/or lithology. For example, sedimentary rocks may be interbedded components together to form a rock. if there were sea level variations in their sedimentary depositional environment. Cobbles: Rounded rock clasts (of any lithology) between 64 mm and 256 mm in size. Liesegang: Coloured or compositional rings or bands in a fluid-saturated rock due to rhythmic precipitatioin. Also known Conglomerate: A sedimentary rock made up of rounded as Liesegang rings. pebbles (>2mm), cobbles and boulders of rock in a finer- grained matrix. Limestone: A sedimentary rock consisting mainly of calcium carbonate (CaCO3) grains such as ooids, shell and coral Cross-bedding: A feature principally of sandstones formed by fragments and lime mud. Often highly fossiliferous. the movement of sand grains in currents to produce layering oblique to the margins of the beds. Member: A lithologically distinct, named lithostratigraphic unit that forms part of a Formation.

Worcestershire Strategic Stone Study 17 Metamorphic: Rocks which have been subject to heat or Sandstone: A sedimentary rock composed of sand-sized pressure which has caused changes in their solid state e.g. grains (i.e. generally visible to the eye, but less than 2 mm mudstone to slate, limestone to . in size).

Microdiorite: A medium-grained igneous rock with the mineral Sedimentary rock: A rock that is commonly formed by the assemblage and chemistry of diorite. binding together (lithification) of sediment particles (e.g. sandstone, siltstone, mudstone, limestone). Mudstone: A fine-grained sedimentary rock composed of a mixture of clay and silt-sized particles. Sett: A square stone used for paving.

Mullions: A vertical, slender pier which forms the division Shales: An argillaceous rock with closely spaced, between the lights (glass) of a window. well-defined laminae.

Ooid: A spheroidal grain of calcium carbonate formed by Siltstone: A sedimentary rock composed of silt-sized grains precipitation (by algae) of calcium carbonate in concentric (i.e. only just visible to the eye). layers. Tonalites: A group of plutonic rocks having the composition of Outcrop: Area where a rock unit is exposed at the diorite but with an appreciable amount of quartz, ie between 5 ground surface. and 20 %.

Pegmatite: A very coarse-grained igneous rock with phenocrysts over 250 mm in length, usually of granitic composition and forming at a late of crystallization.

Polygonal: Many sided. Polygonal masonry is made of stones with smooth polygonal joints between them.

Pyroclastic (rock): A rock formed by the accumulation of material generated by the explosive fragmentation of magma and/or existing solid rock during a volcanic eruption.

Quartz: The crystalline form of silica (silicon dioxide, SiO2 ).

Quoins: The external angle of a building. The dressed alternate header and stretcher stones at the corners of buildings.

Rhyolite: A fine-grained, acidic volcanic rock.

Rubble: Rough, undressed or roughly dressed building stones typically laid uncoursed (random rubble) or brought to courses at intervals. In squared rubble, the stones are dressed roughly square, and typically laid in courses (coursed squared rubble).

Worcestershire Strategic Stone Study 18 Acknowledgements Further Reading

Written by Dr Peter Oliver, this study is the Herefordshire and Barclay, W. J., Ambrose, K., Chadwick, R. A., Pharaoh, T. C. Worcestershire Earth Heritage Trust’s contribution to the (1997). Geology of the Country around Worcester. Memoir for Strategic Stone Study, sponsored by Historic England. All 1:50 000 Geological Sheet 1999 (England and ). images © Cherry Oliver, except for: Brenchley, P. J., Rawson, P. F. (eds). (2006). The Geology of page 3 (top): © John Payne England and Wales (2nd Edition). The Geological Society of page 3 (bottom): © Moira Jenkins . page 10 (top), 11 (top), 16: © Tarnia McAlester Brooks, A., Pevsner, N. (2007). The Buildings of England: Edited by Graham Lott, British Geological Survey. Worcestershire. Yale University Press. Based on the original design by Tarnia McAlester. First published by English Heritage February 2012. Curl, J. S. (2003). Encyclopaedia of Architectural Terms. This version of the atlas was rebranded by Historic England in Donhead. December 2017. The information within it remains unaltered Kearey, P. (2001). Dictionary of Geology. . from the first version. Mitchell, G. H., Pocock, R. W., Taylor, J. H. (1961). Geology of the We are grateful for advice from the following: Country around Droitwich and Kidderminster: Memoir of the Don Cameron, British Geological Survey British Geological Survey. Sheet 182 (England and Wales). Graham Lott, British Geological Survey Old, R. A., Hamblin, R. J. O., Ambrose, K., Warrington, G. (1991). Geology of the Country Around Redditch: Memoir for 1:50 000 Geological Sheet 183 (England and Wales).

Richards, T., Chapman, E., Ashbee, E., Gillespie, R. (2008). ‘Worcestershire Geodiversity Action Plan Phase 2 – Geodiversity Audit’. Final Report (unpublished). Herefordshire and Worcestershire Earth Heritage Trust.

Toghill, P. (2010). The Geology of Britain - An Introduction. Airlife.

Whitehead, T. H., Pocock, R. W. (1947). Geology of the Country around and Bridgnorth: Memoir of the British Geological Survey. Sheet 167 (England and Wales).

Worssam, B. C., Ellison, R. A., Moorlock, B. S. P. (1989). Geology of the Country around : Memoir for 1:50 000 geological sheet 216 (England and Wales).

Worcestershire Strategic Stone Study 19