Search Results for: :
The Bridgnorth Sandstone Formation is a soft, brick red, commonly buff-mottled, Permian sandstone characterised by large dune cross-beds. Formed from wind-blown (aeolian) sand and relatively poorly cemented, it is not widely used in comparison to the Carboniferous and Triassic red sandstones of the county.
The most notably example of its use is in Wribbenhall Railway Viaduct in Bewdley where large blocks with large scale cross-beds can be seen, probably quarried locally. Boundary walls around Bewdley also make use of the stone, as have cave dwellings at Blackstone Rock, carved into the river cliffs.
Pennant sandstone has been widely used in the 20th and 21st Centuries for paving, replacement/restoration and new build. It is a Carboniferous age Coal Measures sandstone, very well cemented and medium to coarse grained. In colour it varies from blue-grey to buff or greenish. Liesegang iron staining is often seen.
Its most distinguishing feature is the presence, in most blocks, of small fragments of coal <1mm diameter. It is also notable for being very tough and so in older buildings may be notable for its lack of erosion. Examples of use include, Worcester Cathedral (as replacement for Highley Sandstone), The Hive, Worcester (as paving) and the extension to the Tourist Information Centre, Church Lane, Bromyard (new build).
Old Red Sandstone
The Old Red Sandstone is a large group of rocks of late Silurian and Devonian age. They were formed in a semi-arid desert environment which has given them their conspicuous red colouring through the intense weathering of iron-bearing minerals. Nevertheless, they are highly variable in outcrop with red, green, purple or brown colourings, coexisting in many cases.
Sandstones, mudstones, calcretes and conglomerates (both pebbly and intraformational) are interbedded with one another as a result of deposition in seasonal, shifting, braided rivers. Sandstones form the best and most widely used building material with calcretes and cornstones generally used only very locally and most likely as a by-product of lime burning.
Generally used quite locally, it is the most important building stone across most of Herefordshire. The variable nature of the stone can give very local character to individual villages.
Particularly notable areas of use include the Golden Valley, the Bromyard Plateau, Ross-on-Wye and the Teme Valley (for instance the village of Clifon upon Teme) however they are extremely ubiquitous across the area of their outcrop.
This famous Upper Jurassic building stone is one of the most important in the country having been used for iconic buildings including St. Paul’s Cathedral and the Cenotaph. It is easily recognised by its pure white or grey colour – lacking the buff or orange tinges of Bath and Cotswold Stone – and its fine grained oolitic character. Its most common usage in Herefordshire and Worcestershire is for monuments, particularly war memorials.
There are three main beds used. The ooidal Whit Bed contains common shells, whereas the Base Bed is generally less shelly in character. The fossiliferous Roach Bed is the most distinctive of the Portland limestones as it exhibits large, open, biomoldic pore spaces. These relate to the leaching out of examples of the large gastropod Aptyxiella portlandica (known informally as the ‘Portland Screw’) and the bivalve Myophorella incurva (‘’Osses Heads”).
The stone was and still is quarried on the Isle of Portland, Dorset, where there are 35 named quarries from which stone was loaded directly onto boats and exported countrywide. Only a few are still being worked.
Portland Stone Details
|Geological Name||Portland Stone Formation|
|Age||Upper Jurassic (Tithonian: 152.1 ± 4 Ma to 145.0 ± 4 Ma)|
|Area of use||Herefordshire & Worcestershire|
|Era of use||Mostly 19th Century and onwards|
A porous variety of limestone similar to travertine, formed by flowing water containing large amounts of dissolved calcium carbonate precipitating over moss and other vegetation. It is easy to saw when wet but dries to a strong, light building stone which is used wherever it is found.
Notable areas of formation and use are the Teme Valley (there is a very large outcrop at Southstone Rock) and the Golden Valley.
It is used for example in St Andrew’s Church, Shelsley Walsh and St Michael’s Church, Bredwardine, as well as further afield for a lightweight vaulting in the aisle of Worcester Cathedral.
Green-grey to buff or pinkish sandstone. Not widely used for building and occurs only in the southern tip of Herefordshire around Goodrich. More extensively used in the Forest of Dean.
Also known as Honnister Slate, this is variety of slate from the Borrowdale Volcanic Group of Cumbria. Unusually it is formed from a tuff (volcanic ash deposit) – erupted during the Caradoc Age of the Ordovician (458 to 448 million years ago) – which has been subjected to high pressure and heat, metamorphosing it to a slate. Large amounts of the mineral chlorite give the slates a green-grey or green colour.
The green-grey slates are from the lower seam quarried near the Honnister Pass (and now marketed as Honnister Slate) while the green slates are from the upper seam near Ambleside. Relict igneous crystals give individual slates a much bumpier surface than a typical mudstone slate (e.g. Welsh Slate) and in some cases roof pitches may be steeper then their smooth slate equivalent as a result.
Many quarries formerly worked the slates, initially as independent companies but increasingly merging into larger conglomerates; first the Lakeland Green Slate Ltd then incorporated in the Burlington Slate Co. in 1975. Today the main workings are quarries at Elterwater (NY 324 048) in the upper seam and the Honnister Slate Mine (NY 222 135) in the lower.
An example of its use is for the Jacob Fountain inside Malvern Theatres. Anonther example of use is said to be the Chancel roof of St Peter’s Church, Bromyard.
In general this is a fine-grained well sorted sandstone often showing cross-bedding. In colour it is crimson to dull brownish-red, chocolate, purple and lavender sandstone from the Carboniferous age Salop Formation (Alveley Member).
Quarried near Alveley, North Worcestershire, the main quarry is just outside the village. Hextons Quarry just north of Upper Arley also supplied a bright red variety from another horizon of the Salop Formation. This is variously referred to as Hexton’s Stone, Alveley Stone or Arley Stone. In addition there are several smaller old quarries in the vicinity of these two main quarries. The location of quarries near the River Severn meant they were easily transported by river and they, particularly Hexton’s Stone, appear at many locations downriver.
Bright red and grey Carboniferous sandstone quarried from Hexton’s Quarry since medieval times.
Ashlar blocks can still be seen abandoned alongside the remains of a wharf on the Severn which was linked to the quarry by a short incline. Stone was transported down river for the construction of Worcester Cathedral and the quayside at Arley.
Other examples of use are in the village of Arley, including St Peter’s church, in All Saints, Wribbenhall and in St Martin’s Worcester. This is one of several Triassic and Carboniferous red sandstones in this area and it can be very difficult to tell them apart.
Olive-blue-grey calcareous siltstones, silty mudstones and mudstones. From a building-stone perspective a classification for the Silurian strata based on rock type is most appropriate, not least because the best building stone yielded by this ‘series’ – the Aymestry Limestone – is diachronous and, in the north-west part of Herefordshire, tends to be variable in its limestone content, grading into the Lower Ludlow Shales Group (below) and Upper Ludlow Shales Group (above) to such an extent that both the precise age and source of the ‘limestone’ blocks observed in buildings are often difficult to determine.
Although the Ludlow Shales comprise two distinct geological units (the Lower and Upper Ludlow Shales groups) separated by the Aymestry Limestone (Formation), they are herein treated together from the point of view of their use as a building stone. The ‘Shales’ are thinly bedded, blue-grey siltstones and mudstones, with some interbedded limestones. When weathered, they become a more olive-buff colour and tend to be more fissile in character.
Though not widely used as a building stone in this area, the Shales may have been extracted during the quarrying of the Wenlock Limestone (stratigraphically below the Lower Ludlow Shales Group) and/or the Aymestry Limestone. The ‘Upper Ludlow Shales’ appear to have provided a more useful building stone, owing to the fact that this group is more flaggy in character and has fewer calcareous beds occuring in the sequence. The ‘Ludlow Shales’ and Aymestry Limestone can be seen in buildings located close to their outcrops both north and east of Ledbury. [Summarised from the Strategic Stone Study Atlas of Herefordshire, English Heritage 2012]
A pale grey to pink and buff coloured sandstone from a bed within the Raglan Mudstone. A medium to coarse grained (unusually coarse in comparison with much of the formation), current bedded sandstone with thin layers of granules (clasts between sand and pebble grade; about 2-4mm diameter) and small pebbles of yellowy quartzite in it.