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Home , Coal Measures Group, Lias Group, Mercia Mudstone Group, Millstone Grit, Zechstein

CHAPTER II REGIONAL GEOLOGY by Graham K. Lott

The ‘quarrying’ and use of local stone in Notting- the comprises a thick succession of non- hamshire, for both building and decorative purposes, marine, green-grey to reddish brown sandstones, dates back to Roman times. However, the lithological siltstones and mudstones, the latter including thinly units that characterise the geological succession interbedded, grey-green, dolomitic, very fine grained within the county contain only a few beds of stone sandstones (known locally as skerry). In contrast, the suitable for these purposes. This lack of indigenous early marine succession is only sporadically stone useful for decorative carving is reflected in the exposed along the northern edge of the low-lying composition of the suite of carved stone fragments Vale of Belvoir and comprises a succession of grey that have been studied as part of this Corpus project. limestones and mudstones (Lias ). The eastern By far the majority of the stones examined consist part of the county is locally blanketed by extensive of lithologies (primarily sandstones and limestones) tracts of glacial and alluvial sediments (unconsolidated sourced from outside the county border. sands, gravels, clays and muds) of Quaternary age.

carboniferous THE GEOLOGY OF Pennine Measures Group Nottinghamshire has a relatively simple geological The Carboniferous rocks that crop out in the west of succession comprising a sequence of eastwards- the county form part of the Pennine dipping units whose outcrops Group. This succession is best known economically extend from north to south across the county (see for its coal reserves but also contains a number of Fig. 3 and Table 1). The geologically oldest beds are relatively thinly bedded, hard, fine-grained, quartzose of Upper Palaeozoic age and crop out in a narrow sandstone beds, some of which have been quarried strip along its south-western border. They comprise extensively for local building stone around, for the lithologically varied coal-bearing sandstone and example, Eastwood, Kimberley and Trowell. However, mudstone successions of the Pennine Coal Measures in general these sandstones are not suitable for carved Group (Upper Carboniferous) and form part of the stonework and have not been identified in the Corpus -Nottinghamshire Coalfield. These beds stones of the Nottinghamshire area. are overlain to the east by a thin, variegated sequence of orange-brown to pale yellow-coloured, dolomitic (or magnesian) limestones, and soft red-brown clays and sandstones of Permian age. Together these geological Group units form the higher ground that characterises the The overlying Permian succession in the western part county’s western border extending from the sandstone of the county can be subdivided into a lower unit of cliffs of Nottingham Castle in the south to Gringley dolomitic limestone (the Cadeby Formation) and an on the Hill in the north. upper interval in which red clays (often termed marls) Continuing eastwards across the county the Permian and sandstones dominate (the Edlington Format- succession is succeeded by a thick Triassic and early ion). The Cadeby Formation, formerly known as the Jurassic (Mesozoic) sequence which underlies the Lower Magnesian Limestone, is the source of Nott- remainder of the county. Typically in Nottinghamshire inghamshire’s best-known building and decorative 11 N 12 CHAPTER II N

Retford

Worksop

Retford

Worksop

Mansfield Sutton In Ashfield Southwell

Mansfield Newark On Trent Hucknall Sutton In Ashfield Eastwood Southwell

Carlton Newark On Trent Hucknall Nottingham Eastwood Beeston Carlton

Nottingham

Beeston 0 5 10 Km

0 5 10 Km

Nottinghamshire Bedrock Geology

Bedrock Geology

LIAS GROUP - MUDSTONE, SILTSTONE, LIMESTONE AND SANDSTONE NottinghamshiTRIASSIC ROCKSre Bed (UNDIFFERENTIrock GeologyATED) - MUDSTONE, SILTSTONE AND SANDSTONE TRIASSIC ROCKS (UNDIFFERENTIATED) - SANDSTONE AND CONGLOMERATE, INTERBEDDED Bedrock Geology PERMIAN ROCKS (UNDIFFERENTIATED) - SANDSTONE AND CONGLOMERATE, INTERBEDDED - MUDSTONE, SILTSTONE, LIMESTONE AND SANDSTONE PERMIAN ROCKS (UNDIFFERENTIATED) - MUDSTONE, SILTSTONE AND SANDSTONE

ZECHSTEINTRIASSIC ROCKS GROU (UNDIFFERENTIP - DOLOMITISEDATED) LIMES - MUDSTONET ANDONE, DOLOMITE SILTSTONE AND SANDSTONE

PENNINETRIASSIC MIDDLEROCKS (UNDIFFERENTI COAL MEASURESATED) FORM - SANDSATIONT ANDONE SOUTHAND CONGLOMER MIDDLEATE, INTERBEDDEDCOAL MEASURES FORMATION (UNDIFFERENTIATED)

PENNINEPERMIAN LOWERROCKS COA(UNDIFFERENTIL MEASURESATED) FORM - SANDSATION TANDONE SOUTH AND CONGLOMER WALES LOWERATE, COA INTERBEDDEDL MEASURES FORMATION (UNDIFFERENTIATED) PERMIAN ROCKS (UNDIFFERENTIATED) - MUDSTONE, SILTSTONE AND SANDSTONE ZECHSTEIN GROUP - DOLOMITISED LIMESFIGURETONE AND DOLOMITE3 PENNINE MIDDLENottinghamshire COAL MEASURES FORMATION bedrock AND SOUTH WgeologyALES MIDDLE COAL MEASURES FORMATION (UNDIFFERENTIATED) PENNINE LOWER COAL MEASURES FORMATION AND LOWER COAL MEASURES FORMATION (UNDIFFERENTIATED) REGIONAL GEOLOGY 13 TABLE 1 Stratigraphical divisions in Nottinghamshire

Geological Period Principal sculptural Rock Type stone units Jurassic (Middle) Group (not at outcrop in Nottinghamshire) present as imported stones ooidal and bioclastic Lincolnshire Limestone Formation limestone Jurassic (Lower) Lias Group none Triassic Mudstone Group mudstone-dominated (includes ‘Skerry Sandstone’) present (sandstone-dominated) Permian Zechstein Group Brotherton Formation (Upper Magnesian Limestone) none dolomitic limestone Edlington Formation none Cadeby Formation (Lower Magnesian Limestone) present sandy dolomitic limestone Marl Slate none Basal Permian Sand none Carboniferous Pennine Pennine Upper Coal Measures Formation none Pennine Middle Coal Measures Formation none Pennine Lower Coal measures Formation none Group (not at outcrop in Nottinghamshire) present as imported stones sandstone, quartzose 14 CHAPTER II stones. These limestones were quarried extensively in façade, which have suffered badly from the effects of the past for building stone at Bulwell, Linby and in the nineteenth-century pollution. Numerous medieval Mansfield area. parish churches in this north-western area of the county The Bulwell-Linby stones are distinctive, both com- have also used these Cadeby Formation limestones prising yellow-brown to orange, coarsely crystalline, for much of their ashlar walling and sometimes for sandy, dolomitic limestone lithologies. They form elaborately carved stonework, for example in the thinly-bedded successions in both these locations, twelfth century at Edwinstowe, and Blyth in the later with individual limestone beds averaging 15–20 cm eleventh. The Mansfield quarries continued to supply and only rarely reaching thicknesses greater than 30 high-quality stone for ashlar and carved decorative cm. Both stones were widely used in the past for stonework until quite recently. However, despite their local construction, particularly in the nineteenth- and obvious local importance and their long history of use, early twentieth-century suburban developments of stone from these quarries has not been identified among Nottingham. Evidence of the use of Bulwell Stone the Corpus stones examined in Nottinghamshire. is widespread, well documented as far back as the Further north, along the western county border sixteenth century by its common occurrence as large with Derbyshire, quarrying of the Cadeby Formation grave-stone slabs and in chest tombs of the period. limestones was also intensive in the past, notably The very extensive, former quarry sites found around Steetley. Here the dolomitic limestone lithol- around Linby in medieval times supplied stone for ogies change to almost pure white, fine-grained, Newstead Abbey and are still operational on a small ooidal and occasionally peloidal, varieties with no scale today. As with the Bulwell limestone the thinly- quartz sand content evident. Again the limestones bedded nature of these limestones, and their coarsely are seen in numerous older local buildings between crystalline character, has meant that they have only Mansfield (Mansfield Woodhouse Stone) and Work- occasionally been used as a source of block-stone sop (Steetley Stone). At Carlton-in-Lindrick, the suitable for carved stonework. However, the evidence church with an early Norman tower provides testa- provided by the early carved stone panel now built ment to the early use of the local pale dolomitic in over the doorway at Papplewick church (p. 131, limestones and their evident suitability for building Ills. 63–7) suggests they could sometimes be used for and decorative stonework. A single carved Corpus decorative work. fragment, reused in the external fabric of its chancel, Further north, around Mansfield the dolomitic was examined and was probably also sourced from the limestones of the Cadeby Formation change quite local Cadeby Formation succession (p. 94). A group dramatically in character, becoming finer grained of rather standard ‘overlap’ grave-covers examined at and pale yellow and white in colour. At Mansfield Blyth, Halloughton and Mattersey Priory also employ the formation includes two relatively thickly-bedded, this stone type (Appendix A, pp. 199, 202, 203). sandy dolomitic limestone varieties known locally as The Permian (Cadeby Formation) white dolomitic the Red and White Mansfield Stones. Both were once limestone from quarries in Derbyshire, notably at extensively quarried as freestones, with the ‘white’ beds Creswell, and Roche Abbey and Cadeby in south being particularly suited for the production of block- , appears to have been widely imported and stone, which was also well suited for carved stonework. used as building stone and for decorative carved work These Mansfield limestones can be distinguished by in medieval buildings in north Nottinghamshire. their very fine-grained quartz sand content, which makes them particularly durable. They were widely triassic used for block-stone and for carved stonework from at least medieval times. The White Mansfield Stone, The Triassic succession in Nottinghamshire is broadly which was until recently still quarried, provided the divisible into two parts, a lower interval dominated intricately carved interior medieval stonework of the by red sandstone beds (Sherwood Sandstone Group, Chapter House in Southwell Minster. The Mansfield formerly the and sandstones) and quarries supplied stone for many prestigious early an upper unit of red mudstones with thin dolomite buildings in Nottinghamshire including Worksop sandstones (skerry) and thick beds (Mercia Priory, in the twelfth century, and Welbeck Abbey, Mudstone Group, formerly the Keuper Marl). also from the twelfth century. The fourteenth-century priory gatehouse at Worksop has a fine collection Sherwood Sandstone Group of carved Mansfield stone figures in its external This group succession is divisible into a lower, REGIONAL GEOLOGY 15 friable, pebbly red sandstone interval, locally named bone fashion, as at Oxton, East Bridgford, Flintham, the Nottingham Castle Sandstone Formation, and Averham, Thorpe, etc. (Lott 2001). However, only at an upper unit of fine, greenish-grey sandstone South Leverton is there any evidence of their use for termed the Siltstone Formation (formerly early carved or decorative work among the Corpus known as the Waterstones). The red sandstones are stone fragments (p. 170). well exposed in the cliffs below Nottingham Castle but have not generally been worked for building or lower jurassic decorative stone as they are too friable to produce durable blocks. However, their comparatively soft Lias Group nature was exploited in other ways in the past, notably The Lias Group succession comprises thinly inter- by the excavation of extensive underground caves for bedded grey limestones and mudstones and crops houses and storage areas, particularly beneath the city out along the eastern margin of the county. The of Nottingham. limestone beds have been widely quarried along In the south west of the county, sandstones of the their outcrop and used as block-stone in buildings Sherwood Sandstone Group crop out in the cliffs along and churches from Willoughby on the Wolds in the the southern edge of the Trent valley. Here they are south to Newark in the north. However, these finely predominantly grey-green in colour and fine-grained crystalline limestones are soft and clay-rich and do not in character. Quarries in these outcrops provided the provide stone suitable or durable enough for carved large blocks of sandstone used to build numerous stonework and they have not been identified among medieval church towers and other structures in this the Corpus stone fragments. part of the county (at Kegworth, Ratcliffe on Soar, Higher in the group occur the distinctive dark Bunny, Sutton Bonington, Keyworth, etc.). However, yellow-brown, ferruginous limestones and sandstones there is no evidence of their use in the Corpus stone (commonly referred to as ironstones) of the Marlstone fragments. Rock Formation. The Marlstone does not crop out The overlying Tarporley Siltstone Formation also within Nottinghamshire but is exposed and was provided sandstone widely used for local building all quarried in the Vale of Belvoir to the south. Occas- along much of its outcrop, e.g. in churches at Gedling, ionally these ‘ironstones’ are used as block-stone in Ollerton, Bothamsall, Eakring and Kirton (Lamplugh buildings in south-east Nottinghamshire, as at Hick- et al. 1911; Lott 2001). However, no examples of its ling, Granby and Upper Broughton. However, they use have been identified in the Corpus stonework are generally soft and can, when exposed in a structure, fragments. At Stapleford the ‘mystical’ Hemlock weather badly. The Marlstone lithologies are not, Stone is an upstanding, elaborately weathered, baryte- therefore, well suited for external carved stonework; cemented sandstone remnant of the Tarporley Siltstone however, a single carved piece has been identified in Formation. the Corpus survey in the internal stonework at Upper Broughton (Broughton Sulney) church in south-east Nottinghamshire (Appendix G, p. 225). This group, despite being dominantly a red mudstone succession, also includes numerous thin beds of grey- green, dolomite-cemented, very fine sandstone, pleistocene (superficial sediments) known locally as skerry. Skerry sandstone ‘quarrying’ Much of the land surface of Nottinghamshire is is known to have been extensive in the past around mantled by a thin covering of Quaternary glacial and Hockerton, Tuxford, Laxton, Maplebeck and East alluvial clays, sandstones and gravels. Sporadically Markham. Their widespread use in buildings from during this period coarsely porous, white limestone Roman times onward suggests numerous small skerry tufas were also deposited at spring lines in various pits were worked along their outcrops. The skerry parts of the Vale of Trent. The development of these beds thicken and thin across the county, enabling large calcareous tufas is commonly associated with exposed (thick-bedded) and small (thin-bedded) skerry blocks carbonate cemented skerry bands within the Mercia to be produced. Large skerry blocks are typically seen Mudstone Group. Occasionally tufa blocks are in the fabric of churches at North and South Muskham, evident in some early external church fabrics, e.g. at Tuxford and Mapperley. Small skerry sandstones have Caunton. However, no examples of their use in carved been used extensively in medieval churches and other stonework have been identified in Nottinghamshire, buildings in Nottinghamshire, often in herring- nor are they present in the Corpus stone fragments. 16 CHAPTER II IMPORTED STONE Anglo-Saxon stonework of St Michael’s church at nearby Stanton by Bridge in Derbyshire. Transport of Millstone Grit Group (Namurian, Carboniferous) the sandstone quarried from these outcrops along the The sandstone dominated successions of this group into Nottinghamshire was also possible do not crop out within Nottinghamshire, but (Fig. 4 below). occur extensively just beyond its western borders in Derbyshire. The Stapleford cross (p. 189, Ills. 125–40) Lincolnshire Limestone Formation (Bajocian, Middle Jurassic) stands within the Pennine Lower Coal Measures Group The Middle Jurassic Lincolnshire Limestone Form- succession which includes a number of sandstone ation forms an extensive outcrop to the east of outcrops. However, the relatively coarse, occasionally Nottinghamshire, extending from north to south granular nature of the siliceous sandstones used in this across the counties of Lincolnshire, Rutland, Cam- cross show greater mineralogical and sedimentological bridgeshire and Northamptonshire. The formation is affinities to sources in the Millstone Grit Group. lithologically very variable but is dominated by ooidal Although, in general, it is very difficult to distinguish and bioclastic limestone beds of variable thickness. the major sandstone beds of the Millstone Grit Group The principal quarrying areas for these limestones one from another, in the absence of any evidence that were around Lincoln, Ancaster and Heydour in the the stone was transported from further afield, it seems north and Clipsham, Weldon, Ketton and Barnack likely that the sandstone used in the cross at Stapleford in the south (Worssam 1999, 17–19). While these would have been locally sourced. Possibly sources limestones most commonly show mixed ooidal and include the coarse-grained Ashover Grit or Rough bioclastic lithogies, occasionally beds showing more Rock sandstones of the Little Eaton or Coxbench- uniform lithological development occur. Most notably Horsley areas in Derbyshire. these include the very coarsely bioclastic Barnack Evidence of the local use of these hard, coarse- Ragstone (Cambridgeshire) and the well sorted ooidal grained, siliceous Millstone Grit sandstones in Derby- limestones of the Ketton / Stamford (Lincolnshire) shire for early carved stone work can be found at area. Bakewell and Wirksworth churches (CASSS forth- In general, the majority of Lincolnshire Limestone coming). The elaborately carved Anglo-Saxon stones examined in Nottinghamshire as part of the stones found in these churches are close to extensive Corpus survey appear to be of the mixed ooidal and outcrops of Ashover Grit, one of the most heavily bioclastic type and were probably originally sourced worked sandstone resources in the Derbyshire area. from quarries in the Ancaster area of Lincolnshire Millstone Grit sandstone ‘quarries’ in general are (Everson and Stocker 1999, fig. 8). Only one sample common along the Derwent valley and have long of the distinctive Ketton ooid-dominated type was supplied high-quality stone into Nottinghamshire, identified during the survey at Averham (p. 93). No e.g. for constructing Lenton Priory in the twelfth examples of the shelly Barnack Rag lithology have century. Easy access from the ‘quarries’ to the River been observed in Nottinghamshire: remarkably, Derwent could have provided an important transport the Barnack-style cover at West Leake (p. 205) was route, bringing roughly dressed sandstone block or produced in a Permian limestone from the Cadeby the ‘finished’ carved stones into Nottinghamshire. formation. In part the lack of use of the southern At Melbourne to the south west of Nottingham limestones may have been a transportation issue, another small inlier of Ashover Grit sandstones is also with the southern sources having to rely on overland known to have been extensively worked from earliest transport while the northern sources were able to times, as is evident from its use in the long-and-short transport stones using the rivers Trent and Witham.