Higher in the Lower Jurassic succession occur the Middle Lias ironstones (Fig.??). Best developed in Oxfordshire (Hornton Stone), Northampton and Lincolnshire (Marlstone Rock Formation). All were commonly used in the past for local buildings and occasionally exported further afield. To a lesser extent the Lower Lias Frodingham Ironstone was also used for building north of Scunthorpe. Only the Oxfordshire quarries are still operating and new sources of the stone are urgently needed if conservation of the large, and rapidly decaying building stock, in the other areas is to be supported.

Within the Upper Lias only the orange-brown, Ham Hill Stone from Somerset, a locally developed ferruginous, sandy and shelly limestone, has been widely used as a building stone and is still actively quarried (Durman 2006).

These typical grey Lias limestones pass laterally into coarser conglomeratic limestones, representing beach or cliff-line depositsion at the coastline of this Lower Jurassic sea. They are preserved only in the South Wales and Bristol areas. In South Wales these whitish, coarse grained Lias rocks are termed the Sutton Stone and in the Bristol / Somerset area the Brockley Down Limestone (Downside Stone), both have been widely used locally as building stones.

Middle Jurassic limestone Cricklade

The limestones of the Inferior Oolite Group outcrop extensively from Dorset to Lincoln. Some of the best known freestones from this unit include the Guiting, Doulting (Wells Cathedral), Dundry (Llandaff Cathedral), Whittington (Cheltenham Stone; Price 2007) and Painswick stones of Gloucestershire and Somerset and the Lincolnshire Limestones from Ketton (various Cambridge colleges), Clipsham (extensively used for on-going restoration the Palace of Westminster), Weldon, Barnack (Peterborough Cathedral), Stamford, Ancaster (Wollaton Hall) and Lincoln (Silver Bed of Lincoln Cathedral) in Rutland & Lincolnshire. The high quality of these stones is self evident from their widespread and continuing usage and it bears repeating that the geological term Inferior Oolite has nothing at all to do with quality and is used simply to denote their position beneath the Great Oolite Group.

Marlstone at Broadway Gloscestershire

The limestones of the overlying Great Oolite Group include the important Bath stones (Box Ground, Stoke Ground, Westwood Ground, Combe Down, Monk's Park etc.), the Cotswold and Oxfordshire stones (Taynton, Windrush, Barrington etc. Arkell 1977) and others that are locally important such as the Blisworth Limestone.

The Bath Stone mines and quarries have a long history of production going back to Roman times. Their greatest phase of exploitation took place throughout the 19th century when these pale yellow oolitic limestones were widely exported for use in the towns and cities of the southern Britain. London, for example, has many 19th century buildings originally built of Bath Stone (Buckingham Palace, Aspley House). Mining of the stone was so extensive that much of the environs of Bath are undermined by tens of kilometres of subterranean caverns.

Over much of the Cotswolds the Great Oolite limestones, though of equally high quality and extensively quarried for local building, never achieved the enviable reputations and hence commercial success of either the neighbouring Bath or Oxford stone quarries. The best known of the Oxford stones is probably the Taynton Stone, which together with stones from several other quarries along the Windrush valley, were used extensively in many of the prestigious Oxford colleges, churches and other buildings in the area (Bleinheim Palace), from Medieval times until relatively recently.

Cotswold stone slates used as wall cladding

Extensive quarrying and mining of these limestones also took place across the outcrop from the Cotswolds into Rutland. Stonesfield (Oxfordshire) and Colleyweston (Rutland) were two of the better known areas of stone slate mining but dozens of small quarries also exploited the limestones from other limestone units like the Forest Marble (Judd 1875; Woodward 1894; Aston 1974)

Upper Jurassic building limestone resources
The Upper Jurassic succession of southern Britain is dominated by mudstones with subordinate limestones, sandstones and ironstones. However, possibly the best known of all of Britain's building stones, the white oolitic and shelly Portland Stone, along with several locally important limestones, are quarried from this part of the Jurassic succession. The pre-eminance of the Portland Stone is all the more surprising when you consider that it has only been exploited commercially since the late 17th C. There is little or no evidence of its use before this date, outside the local area, despite its obvious qualities and the accessibility of the quarries by sea. Portland Stone has been used extensively in many of Britain's towns and cities (e.g. in civic and university buildings in Cardiff, Nottingham, Leeds and Liverpool). Its most widespread use is in London where it has proved to be particularly resistant to modem day problems of pollution (St Pauls, Whitehall, Admiralty Arch etc). In the Vale of Wardour equivalent beds of the Portland Stone include the sandy limestones mined at Chilmark. The Chilmark or Tisbury Stone, which was used to build Salisbury Cathedral and many other local buildings, is still mined and quarried in the Chilmark-Tisbury area.

Purbeck stone for walls and roofs

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