Malvern building stone walk

Wednesday 25 May 2016 Led by Kate Andrew, EHT

The walk started at Station, outside the booking hall (by water trough) (Grid Reference SO 78168 45759). This is location 1 on the map below. Kate explained that the walk followed a trail for one of the new Earth Heritage "Geology and Walking trail guides". This has not yet been published, but is expected to be called "Explore Malvern - Spouts and Springs". The total length is abound 3km if one were to finish at the start point. 1. Malvern Railway Station We examined the water trough by the Great Malvern railway station entrance. This had been installed in 1880 to supply drinking water for the horses providing transport to and from the station. Kate explained the types of building stones used for the trough, and then we looked at the wall itself.

The trough had alternative red and cream stones above the spout. The red stones are a soft Triassic sandstone which is probably the local Bromsgrove sandstone. The cream stones are oolitic limestone - Bath Stone. The two supports for the trough are a green sandstone - Cradley Stone.

We then looked at the stones in the surrounding wall which are constructed from random pieces of Malvern stone rubble. The majority of the pieces were diorite, but the odd piece of red and basalt. Some of the diorite had an external covering of the greed epidote. We also found a sample of Barite - Barium Sulphate (top left in picture). This white is precipitated in hot hydrothermal veins created in faults in the Malvern rocks. Barite is mostly found in Tank Quarry.

2. Orthodontist Centre - 9 Imperial Road This is a fine nineteenth century building showing off various building stones. The majority is built from pale green Cradley Stone. This is lower Devonian in age and was quarried five miles away. Cradley Stone is used extensively for house building in Malvern.

Around the edges of the rough Cradley Stone other smoother stones are used, a style known as rustification. The window surrounds are a honey coloured oolitic limestone from the Cotswolds. On either side of the door there are two red sandstone pilasters made from a Triassic sandstone. 3. Thornbury House - 16 Avenue Road Thornbury House is again built using Cradley Stone. It also has a similar rustification style, but we were told that this is somewhat artificial. The same Cradley Stone is used for both the walls and the window surrounds, they are just dressed differently.

Of interest is the extension added to the right if the main house. This was build using Forest of Dean sandstone which is Carboniferous from the Pennant Sandstone Formation. The Cradley Stone quarry stopped working in the mid twentieth century so was unavailable for use. There is a good colour match however, the Forest of Dean sandstone having a slightly grey colouration. Kate told us that the two stones will weather differently as well. The Forest of Dean sandstone has silica cementing the sand grains together whilst Cradley stone uses calcite. 4 - No 12 Avenue Road

Another nice residential property, the walls constructed using Malvern stone. The windows are a bit more interesting, with oolitic Limestone for the window edges and what was thought to be Cradley Stone above the windows. 5 - Elmslie House - 8 Avenue Road Another house constructed on Malvern stone. We looked at the colour difference between the main house and the extension. The gable end of the main house is built from very red (acidic) Malvern Stone and the extension from a darker, more basic stone. We discussed the difference between these two terms, acidic and basic. It comes down to the chemistry of the magma. The paler, acidic rocks have more quartz and feldspar in them, the basic rocks lack these. John Payne enlightened us as to how the term originated. It was initially thought, incorrectly, that the silica in the rocks came from a chemical reaction involving silicic acid.

We looked at some of the rocks in the pavement walls. As well as some basalt and epidote we found examples of slickensides. One good example, which is easy for others to find, is in the fourth cap rock to the right of the gateway (on Avenue Road). Slickensides are a smooth polished surface on a rock caused by the frictional movement of rocks along two sides of a fault. 6 - Priory House At the entrance to Priory House we examined the pillars. These looked as if they were originally Cradley Sandstone (light green), but there had been an amount of repair using Hollington Stone from Derbyshire (red).

The entrance pillar to Priory House

Priory House was originally build by Dr. Gulley, one of the founders of Malvern's water cure in Victorian times. The site and gardens were bought by the Council in 1927 and became the Priory Gardens and Council Offices. The buildings are built with Cradley Stone and oolitic Bath Stone. We examined the repair work to the original stonework, some good and some not so. A consistent problem would appear to be water ingress into the sandstone which is then trapped by the impermeable pointing, causing erosion over time.

On either side of the main entrance there are two red granite pillars. Not local, this granite consists of large pink feldspar crystals ringed with quartz. We found a xenolith, a dark piece of country rock which had fallen into the magma whilst the granite was crystallizing.

Granite pillars at the entrance to Priory House - plus xenolith

7 - Swan Pool spring At the northern end of Swan Pool there is a spring which supplies the water for it. The spring line is probably the junction where the sandstone abuts the Malvern granite (covered with glacial head). Like most of the springs in Malvern it is probably not a good idea to drink the water without boiling, only the water from the Malvhina is safe as it is filtered.

8 - Jacob fountain inside Malvern Theatres This fountain replaces the original one installed in the Winter Gardens in 1923 (which was a lot more pleasing to the eye in the editor's opinion). It commemorated Dr. Jacob, local physician and leader of the council. The green paving around the base is made from Westmorland slate, a volcanic ash from the Borrowdale series. It is slightly metamorphic. The basin itself is Carrara marble from Italy.

Jacob fountain and the base 9 - South Wall of Malvern Priory From Grange Road we viewed the southern wall of Malvern Priory. We could see a mismatch of repair work with many different colours of stone. The stone used was what was to hand at the time over many centuries. Kate picked out Bromsgrove Sandstone, Hollington Stone, Cradley Stone and oolitic limestone from the Cotswolds.

10 - Park View - 33 Abbey Road On the approach to Park View we looked at a series of cobble setts used for paving. Kate thought these were Clee Hill Dhustone, a Carboniferous dolerite. Setts from here tend to be square and very black. Note that the rectangular items between the setts are normal bricks.

11 - Ward Jackson's fountain The pipe in the arch in this wall was once a prolific spring, but is now blocked off. It was built in 1868 by Major Ward Jackson on land donated by Miss Mary Palmer. The pure water supply was used for the good of the town, unlike those who used the Malvern water for their commercial gain.

12 - The Wilson Memorial

The current Wilson Memorial replaces the previous memorial and fountain which were demolished in 1948. It is to commemorate Dr. James Wilson who established the water cure in Malvern. Unveiled in 2015, this new memorial is carved from a block of Carboniferous Pennant sandstone from the Forest of Dean. The memorial itself shows faint cross bedding and some brown liesegang rings. The rings are caused by iron staining. The paving slabs around the memorial are of the same material and show ripple marks and flecks of organic coal. 13 - Warwick Court - opposite 33 Abbey Road Firstly we looks at Park View. This is now flats, but was built by Dr. Gully who used it for his water cure premises between 1845 and 1867. At that time it was known as the Establishment. When the water cure had its day it became the County Hotel, and then an MoD hostel.

Across the road from Park View we looked at Warwick Court, and John Payne told us something about its underlying geology. Recently, during the construction of new houses adjacent to the main Wells Road, a lovely exposure of Triassic Bromsgrove Sandstone was uncovered. As well as the Sandstone there were same glacial deposits thought to be material washed down into a side channel next to the Malvernian rocks of the hills. There was not enough exposure to be definitive, and it is now completely covered up. John explained that the Malvern town centre is where it is because there is a long stretch of Bromsgrove Sandstone, providing a stable and flat platform for the main road and the houses around it. 14 - Abbey Hotel The Abbey Hotel is built from dark diorite and granite Malvern Stone with Cradley Stone dressings and Bath Stone balustrade to the entrance. In places, the Cradley Stone has been replaced with repairs of Forest of Dean Pennant sandstone. 15 - Priory Gatehouse Priory Gatehouse - south elevation

Forest of Dean Pennant sandstone has been used to repair the window mullions which were originally of a softer green sandstone (as pointed at by Kate). This could be Cradley Stone although the pale green colour is more typical of Arden Sandstone, exposed at the southern end of the . Just below Kate's umbrella we saw a stone with iron concretions. We decided it was not Cradley Stone as there was no reaction with acid, but after that we were none the wiser.

Priory Gatehouse - arch Kate thought that the large iron concretions within this pale sandstone suggest that it may be Carboniferous stone from Stanley Quarry, next to the River Severn in South Shropshire. The red sandstone cut with veins is Bromsgrove Sandstone and likely to have been extracted locally (possibly the outcrop near Abbey Road).

Carboniferous stone from Stanley Quarry Local Bromsgrove Sandstone

Priory Gatehouse - north elevation The north facing elevation was re-clad in the 19th Century with an oolitic limestone, probably Cotswold stone. Moving south from the gatehouse and looking high up towards the Priory we saw some medieval floor tiles. These had been used in Victorian times as a building material. North elevation of Priory Gatehouse Medieval floor tiles used as building stone 16 - The Malvina Fountain and Enigma fountain Both the Enigma fountain and the Malvhina fountain use the same stone, a mica-rich Carboniferous sandstone from Yorkshire called Yorkstone. There was some debate as to whether this was actually sandstone from the Forest of Dean, but those who remember the stone when first installed said that it was a bright yellow colour. So, it was accepted that it was from Yorkshire. The water from the Malvhina fountain is the only safe water to drink from the Malvern Hills springs without boiling first, being filtered.

The Malvhina fountain The Enigma fountain

17 - Lloyds Bank What is now Lloyds Bank was formally the Crown Hotel, the original home of the water cure in 1842. The water cure then moved premises to Park View (see number 13) when it became established. The building is constructed of shelly oolitic limestone, a mix of grey-white Portland Stone and a paler yellow Bath Stone from the Cotswolds. We examined a stylolite, a serrated surface in the rock where mineral material is removed under pressure. Also of interest is the door step into the bank. Kate said that this was travertine, from Italy, a limestone deposited by hot mineral springs. However, there is an alternative view, which we have discussed on previous field trips, that it is in fact a section through a stromatolite. The mystery is unresolved.

Stylolite - Lloyds Bank Entrance step to Lloyds Bank

18 - Spring at the former Burrow Bottling works Approached through a courtyard, there is a brick arched on the far right end. In the arch spring water trickles out over a face of red Bromsgrove Sandstone, with an upper layer of head (glacial deposits). This is one of the few places where this junction can be seen in-situ. The bottling works collected water piped from St. Anne's Well and stored it in huge cisterns built of glazed bricks.

Brick arch in courtyard Bromsgrove Sandstone with head above

19 - Medieval teaching cross in Abbey churchyard We looked at a mediaeval teaching cross in the Abbey churchyard. The original Cotswold limestone had been repaired with concrete in Victorian times. If interest were a large number of Pentacrinites fossils, these five sided crinoids were common in the early Jurassic period.

Mediaeval preaching cross Pentacrinites crinoid fossils

20 - Malvern Priory We finished the walk by looking at the building stones used in the building of the outside of Malvern Priory. There is an eclectic mix of different sizes and colours, reflecting the repair work done over many years, using the building stones available at the time. We noticed Hollington Stone, Forest of Dean sandstone and Bromsgrove Sandstone. Finally we looked at the Lady Chapel, the oldest part of the building.

Many coloured stones used to repair. Lady Chapel

Local building stones seen

The information below (except Yorkstone) is based upon the Earth Heritance Trust Building stone database. It is in alphabetical order. See http://www.buildingstones.org.uk/building-stones/

Arden Sandstone Fine to medium-grained, variably coloured green, brown, buff and mauve sandstones with some beds of conglomerate which occur locally. Often cross-bedded with planar or trough-shaped laminations. Used locally along its outcrop which forms a rough E-W belt from Malvern Hills in west to Inkberrow in east. Local varieties include grey Inberrow Sandstone and grey to white Pendock Sandstone which is notably used in large blocks in the tower of Pendock Old Church.

Bromsgrove Sandstone

Red and grey, sometimes mottled, Triassic Sandstones from the Bromsgrove Sandstone Formation quarried in the Rock Hill and Hill Top areas of Bromsgrove. Used locally mainly for large boundary walls it was most probably exported and is used across the county. Several other sandstones from the same geological formation are used as building stones including Hadley, Ombersley, Holt and Hollington (from Staffordshire).

Bath Stone Very high quality Jurassic limestone from the Chalfield Oolite Formation quarried in a variety of locations east of Bath. Many of the Bath Stones come from the Bath Oolite Member which is a true freestone, lacking fossils or lamination. The quality of the best Bath Stones is such that they have been mined deep underground. Individual examples may be difficult to distinguish from higher quality Cotswold Stones. The lack of fossils in many examples and generally paler colour are the most distinguishing features. There are various named variants, some of which may show some distinguishing features. Stoke Ground (quarried in Limpey Stoke, Wiltshire) has a base bed with distinctive circular patches of fossil and cement material. Box Ground (mined in the Box Tunnel Mine) is sometimes characterised by calcite veins running perpendicular to bedding. Many of the mines and quarries in Wiltshire only became major concerns after the completion of the Kennet and Avon Canal in 1810 and so the date of building can serve to eliminate them as a possible source. There are several sources still operating of which Stoke Ground is probably the best known.

Cradley Stone A green-grey variety of Freshwater West formation (previously called St Maughans). A sandstone quarried in the Ridgeway Cross area and used extensively in Malvern. It can be difficult to distinguish from the Halesowen Formation which is also occasionally used in the area. Cradley Stone lacks the iron nodules sometimes seen in Carboniferous Sandstones.

Dhustone Several quarries on Titterstone Clee Hill working the Dhustone, a Carboniferous dolerite sill to produce kerbstones and setts for road paving and in the 20th Century aggregate for roadstone.

Forest of Dean sandstone 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).

Hollington Stone A red Triassic sandstone from the Bromsgrove Sandstone Formation of Staffordshire, Hollington Stone is one of the main commercially available red sandstones. It is commonly used for modern repairs and replacements on red sandstone buildings whose original sources are no longer available. In colour it is a brownish red, pale buff or mottled between the two and the rock is almost has diffuse laminae in variable colours. Compared to local Bromsgrove Sandstones it is of a far less bright red and there is often a conspicuous sparkle to the stone in sunlight due to a recrystallised quartz cement. Recognisable by its characteristic buff mottling (if present) and the fine drapes of mud defining cross- bedding and lamination. Intraclasts of deep red mud are relatively common, as are small (<0.5cm) area of barytes cement which appear as white patches on the surface of the stone which stand proud when weathered. As of 2014 it continues to be quarried from five quarries in a small area near the Staffordshire village of Hollington; Broadmoor Side Quarry, Great Gate Quarry, Horton, Redstone Quarry and Tearne Quarry.

Malvern Stone Igneous rubble stone used in Malvern and around the Malvern Hills. A variety of lithologies make up the Malvern Hills of which diorite and tonalite (intermediate between granite and basalts) are the most common. , pegmatites, dolerites, basalts and ultramfic lithologies also occur. Many of the rocks have been sheared and altered by fault movement, particularly south of the Wyche, giving them the appearence of high-grade metamorphic rocks. These are less used for building however as they tend to be more fissile. Owing to the highly fractured nature of the rock, it is almost impossible to produce dimension stone leading to the distinctive random rubble style of construction of Malvern buildings. A great number of quarry operated in the hills, mostly extracting rock for aggregate but also for building. The last of these, Tank Quarry on North Hills, ceased to operate in the 1970s.

Portland Stone 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. It's most common usage in and 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.

Stanley Quarry An alternative name for Stanley Quarry is Highley Quarry. The rock is from the Halesowen Formation a Carboniferous sandstone found in North Worcestershire from Highley to Abberley. Generally greenish to buff, the stone is commonly micaceous and cross-bedded and marked out by the frequent occurrence of small nodules of iron which appear as dark spheres or irregular patches which tend to protrude from the surface. Orange goethite iron staining, particularly on joint surfaces is common. A couple of local variations occur: Highley Sandstone was quarried in Highley, Shropshire, at Stanley Quarry which in medieval times was owned by Worcester Diocese and forms an important source of stone for the early Cathedral. There are also documentary sources of its use in various bridges along the Severn including Worcester and Bewdley.

Westmorland slate 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 than their smooth slate equivalent as a result.

Yorkstone Yorkstone is a variety of sandstone, specifically from quarries in Yorkshire that have been worked since mediaeval times. Yorkstone is a tight grained, Carboniferous sedimentary rock. The stone consists of quartz, mica, feldspar, clay and iron oxides. Known for its hard-wearing and durable qualities, Yorkstone has been used in a wide array of building, construction and landscaping applications around the world for many years. The traditional London paving stone has been Yorkstone. Yorkstone is popular in both new construction and restoration. The colour of Yorkstone depends on the within its makeup and differs throughout the quarries from which it is mined. Newly quarried Yorkstone is usually available as slabs for paving, setts and walling stones. Reused Yorkstone paving, salvaged from demolished sites, is valued for its naturally weathered surfaces.