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Introduction to Herefordshire Archives

30/11/2015
10:30 am - 1:30 pm Introduction to Herefordshire Archives
Herefordshire Archive and Records Centre, Hereford

Leominster History and Buildings Walk

13/11/2015
10:00 am - 12:00 pm Leominster History and Buildings Walk
Broad Street Carpark, Leominster

Ludlow, Murchison and the Limestone Conundrum

Tectonic plate reconstruction of the mid Silurian (~425Myrs ago) during continental collision. Directions of convergence indicated by yellow arrows. (Base image © Ron Blakey, Colorado Plateau Geosystems, Inc.)

Tectonic plate reconstruction of Europe during the mid Silurian ~425Myrs ago during continental collision between Avalonia, Laurentra and Baltica. Directions of convergence indicated by yellow arrows. Base image © Ron Blakey, Colorado Plateau Geosystems, Inc.

In the mid Silurian, about 430 million years ago, the present day area of England lay at the north eastern margin of a continent called Avalonia. To the north lay the Iapetus Ocean and beyond that the continent of Laurentia; made up of parts of North America, Canada, Greenland and what would become Scotland. Continental drift caused the gradual closure of the Iapetus and a collision between Avalonia and Laurentia which brought Scotland and England together as one landmass.

The seas on the continental margins of Avalonia at the edge of Iapetus during its final years provided the environment in which the famous fossiliferous limestones of the Silurian were deposited. Sea level rose and fell through the Silurian, in response to global variations in climate and volumes of ice at the poles. During warmer periods, large transgressions of the shelf occurred and during these times a shallow sea stretched from approximately the Welsh border to well east of the Malvern Hills across the Welsh Borderland. Two such periods correspond to the best known units in the succession; the Wenlock and Aymestry limestones.

Hand coloured generalised cross-section of the Silurian stratigraphy in the Welsh Borderland, from Murhison's The Silurian System (1839) [image © H&W EHT]

Hand coloured generalised cross-section of the Silurian stratigraphy in the Welsh Borderland, from Murhison’s The Silurian System (1839) [image © H&W EHT]

One of the first geologists to really understand the stratigraphical order of these limestones and to map them right across the area was the famous Sir Roderick Impey Murchison. Born the son of a wealthy landowner, Murchison was as arrogant as he was talented, famously arguing bitterly for many years with his onetime friend, Adam Sedgwick, over the correct categorisation of the strata between his Silurian and Sedgewick’s Cambrian System, as if over some disputed territory. In the Silurian System, published 1839 he set out the stratigraphy for the Silurian, divided into four parts and founded on palaeontological evidence, which largely survives to this day. He recognised that a similar sequence of rocks could be found in diverse locations including the Mortimer Forest, Wenlock Edge and the Woolhope Dome. If we look at his beautifully hand coloured cross sections we see the succession up through Wenlock Shale, Wenlock Limestone, Lower Ludlow Shales, Aymestry Limestone and Upper Ludlow Shale that geologists recognise today (despite changes in the number of units and their names over the years). This process of pattern recognition to correlate the sequence of rocks in one area with that of another is the enormously powerful basic method at the heart of most geological mapping.

However when we come to look at building stones and try to trace their past movements from quarry to building we have a problem. The quarrymen, labourers and builders of the past, (unsurprisingly) not thinking about stratigraphy, have removed the stone from its geological order and pattern creating a jumbled jigsaw of blocks. We are thus left with the lithology alone to go on.

Welsh Basin paleogeography during Wenlock times, adapted from Bassett (1974)

Welsh Basin paleogeography during Wenlock times, adapted from Bassett (1974)

This would be fine if the Wenlock limestone or any other unit of rock was the same everywhere but it is not. A brief consideration of the geography of the area during the Silurian is enough to convince us that conditions of deposition likely varied between one location and another. There are numerous variants of palaeogeographic reconstruction but all agree broadly that there was a shoreline somewhere east of the Malverns and that the shelf edge – the break between the shallow seas of the continental shelf and the deep ocean – began at about Ludlow, with water depths rapidly increasing to the west. Within this environment the “typical” Wenlock limestone, rich in fossils, which has attracted the attention of so many palaeontologists, formed a barrier reef stretching from the eponymous Wenlock Edge to Ludlow and running at an oblique angle to the shelf edge. As it approached Ludlow, being nearer to the shelf edge, and therefore less protected from large storms sweeping in off the open ocean, the reef-building corals and shells found it harder to survive. As a result the number of fossils and the amount of lime (a direct by-product of their biological activity) in the rock decreases. Consequently the Wenlock Limestone changes greatly in character across the area. The same is true of the Aymestry Limestone.

A further problem has emerged more recently due to the work of the Ludlow Research Group, a collective of geologists who sought to reinterpret the Silurian stratigraphy of the area from the 1950s onwards. One of their findings, based on very detailed analysis of the fossils in each bed, was that the top of the Aymestry limestone was not the same age everywhere. They proposed a new name for most of the formation – the Bringewood Beds – based chiefly on the occurrence of fossils. This means that in some places (including the type section [pdf]) what would have been called Aymestry Limestone in the older terminology is now placed in the overlying Lower Leintwardine Beds. This gives us a problem when we come to classify building stones. A stone which looks like Aymestry Limestone might be one of three different formations. In a quarry or an outcrop we might be able to establish its age by comparison with type sections but, as previously discussed, in a building such extra information has been lost. Because of this we will probably have to keep using the term Aymestry Limestone in the context of buildings until such a time as the exact formation of the stone can be properly determined.

Kirkidium Knightii the zone fossil for the Upper Bringewood Beds (from Holland, Lawson and Walmsley, 1963)

Kirkidium Knightii the zone fossil for the Upper Bringewood Beds (from Holland, Lawson and Walmsley, 1963)

How, then, do we overcome this conundrum to correctly identify the sources of building stones and properly name them? Given the stratigraphic units are defined by their fossil content, fossils are an obvious place to start. Most units lack a single diagnostic zone fossil, however, positive identification of any fossils to species level will help to limit the possibilities of what it might be. The Aymestry Limestone (or more properly the Upper Bringewood Beds) does have a defining fossil, Kirkidium knightii (previously known as Pentamerus knightii and Conchidium knightii), which is only found within the formation. These are strong shelled, ribbed brachiopod molluscs well adapted to life in the comparatively rough waters of the marginal continental shelf. Finding these in a building gives us an unequivocal identification of the formation. We have recorded examples in buildings including Gatley Park Folly (where we have the additional surety of a personal memory of the stone having been picked from the Aymestry Limestone in Leinthall Earls Quarry) and the tomb of Thomas Andrew Knight, a friend of Murchison’s for whom the fossil was originally named.

Other stones used in the area include Downton Castle Sandstone which is an important source of dimension stone for quoins and lintels, Grinshill Sandstone from Shropshire, which is common in Victorian and later repairs, and even Coal Measures ironstone from Clee hill, used for the copings of Pipe Aston Church. The latter of these is likely material that fell off a cart bringing ore to the forges that existed around the area from the 16th century, particularly in Bringewood. There the coincidence of ready supplies of timber for firewood, and the strong flowing Teme to power the bellows made an ideal location for iron smelting, upon which the Knight family fortune was made.

In order to further pin down the sources and identities of limestones we are now planning to undertake a programme of measurement of geochemical data by Portable X-Ray Fluoroscopy (PXRF). It is hoped that this may give us a more objective way in which to fingerprint different formations or individual quarries and tie them to the historic buildings they have supplied with stone.

This article is based on a lecture given at a Geologists’ Association regional conference, The Geology of the Marches Murchison to the Modern Era, in Ludlow, Shropshire, 2nd-4th October 2015. We are indebted to project volunteer Michael Rosenbaum for much of the research.

 

Our New Building Stones Researcher

Photo of archivist Jenni WaughThe Building Stones team is pleased to be joined by professional researcher Jenni Waugh. Jenni will be working on the Building Stones project for one afternoon a fortnight helping to fill in some of the gaps in our database and follow up leads on specific buildings or quarries from volunteers unable to make it to The Hive.

Although researching in archives can be slow, and the bits of information are often not easy to find, there have been some promising leads as a result of research by volunteers. Using a source in The Hive, volunteer Maggie discovered that the stone used for the original Worcester Bridge came from Farnol Moor Quarry owned by a Mrs Wollascot from Shropshire. Although we haven’t located the quarry yet, further research by Maggie suggests it is located near Bridgnorth. Maggie also discovered that when repairing the bridge in the 1930s the stone specified was from Darley Dale in Derbyshire. The current owners of the quarries have provided us with lots of information about their stone and we are now hoping to match this to the stone left in the bridge.

Other information found in the archives has identified that Earl Somers donated the stone for Hollybush Chapel from his Eastnor Estate free of royalty and that the farmers of the district gave their services in hauling it. It has also come to light that the former Lea and Perrins Chemist shop, on Bellevue Road in Great Malvern, used Cradley Stone to face the fronts of the houses.

Update Nov 2015: Jenni will be running an introduction to the new Herefordshire Archives (HARC), together with Rhys Griffith, the Senior Archivist, on 30/11/2015. For more details see the event listing. She will be available to help volunteers with their research at HARC in the New Year.

Herefordshire & Worcestershire Building Stone Database Goes Live

The interactive map which displays the database data.

The interactive map though which the database records can be explored

The A Thousand Years of Building with Stone project team is very pleased to announce that, as of this month, the new website and database for the project is live on the web. It has been a long hard road to get here, but with almost seven months of development and rigorous testing of the site since Christmas by project volunteers, we are now happy with the finished article. The website combines public-facing news, blogs and events, a searchable database and interactive map (see overleaf) and a volunteer-only login section. This section allows anyone working on the project to enter data, see what others are working on and collaborate on different aspects of a building record. Going forward, the focus now will be on raising awareness of this important new resource among a wide variety of groups and acting on continuing feedback from end-users and volunteers alike to make tweaks and improvements.

In all aspects, building stones HQ remains a hive of activity with talks, training events and roadshows already bringing in nearly 500 people so far this year alone. Many more are planned including workshops at the upcoming Geologists’ Association Symposium in Ludlow, presenting the database to the National Historic Environment Record Forum, and embryonic plans to host our own end of project conference. On top of this project staff and volunteers are scheduled to deliver a multitude of walks and talks across the two counties over the next few months.

We are increasingly seeing small breakthroughs in the research by volunteers. These include snippets of information that have revealed the provenance of the building stones used in Hartlebury Castle, found by Anthony, and the old Lea & Perrins Chemists in Malvern, while casting doubt on that in Worcester Bridge and Berrington Hall. Excellent work by volunteers is untangling the knotty details of stone use in Kington, the Ludlow Anticline and Bredon Hill, to name a few, often with unexpected results and fascinating stories. If we are learning anything it is that from any angle this research is not easy. Nevertheless that challenge serves to make every bit of progress more satisfying.

Scientific testing is well underway on a mini mountain of thin sections from the Bromyard area, the analysis of which has been greatly aided by volunteer Logan’s help. The limiting factor in this is always the availability of stone samples so if you do hear of renovations or alterations taking place on stone buildings we would be very grateful of efforts to secure samples of any unwanted stone.

We are also well on the way planning building stone trail guides and publications and, as is rather a developing theme, in this we have been very pleased to see the volunteers taking a strong lead. Groups in Bredon Hill, Kington and Bromsgrove have all begun work on interpretation material, the results of which we await eagerly.

Now in our third year of the project, the next 12 months for us will really be about doubling down and extending the successes we have seen so far and getting ever more stuck into the difficult job we have set ourselves. We very much look forward to telling you what we’ve learnt.

 

This article original appeared in Earth Heritage Trust News, Spring 2015. Click here or on the image above to explore the database.

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Events

Malvern walking festivalFrom walks to talks, and from family fun days to Three Counties Show we run a wide variety of events year-round, across Herefordshire and Worcestershire. See below for details of upcoming events.

Booking information is at the bottom of each event’s listing page. Most of our events are free and are open to all, although first preference will be given to volunteers on the project for any training events.

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Date/Time
Date(s) - 13/11/2015
10:00 am - 12:00 pm

Location
Broad Street Carpark

Categories


Join this walk led by Graham Cooper and hear about the history, myths and buildings of Leominster

Go to the place where Eadfrith converted Merewald, stand at the Iron Cross, Gaze on Leominster from the old walls, hear about turnpikes, ponder on the location of the Bargate, see where the Rebecca riots in Leominster took place and where the tollgate to Ludlow was, look at interesting buildings (stone or otherwise!) and visit the Lion Ballroom

This event is free. Please wear suitable footwear and clothing.

 

Meet at Broad Street car park pedestrian exit (other end from the Factory Shop)

https://www.herefordshire.gov.uk/transport-and-highways/parking/car-parks-council/leominster-car-parks/broad-street-car-park

Bookings

Bookings are closed for this event.

Leominster & Berrington

Leominster itself has relatively few stone buildings although those that remain include the remains of the Benedictine Priory for which stone was clearly brought some distance in times past.

The Kington, Leominster and Stourport Canal is an unfinished canal, with its original aim being to bring agricultural produce from the area across to the River Severn and beyond. In 1859 the Canal was sold to the Shrewsbury and Hereford Railway, who used much of the route for the Tenbury and Bewdley Railway line. Despite this unfortunate history, evidence of the former canal, and indeed railway, can still be seen along its course, with a number of interesting stone structures, whose origins are yet to be discovered. Immediately adjacent to the Canal route north of Leominster lies Berrington Hall, a National Trust property, which is believed to be constructed of local stone, said to have been brought in by a specially constructed railway line. This is the subject of ongoing investigations.

Linton & Gorsley

The parish of Linton Old Gore lies in southern Herefordshire, close to the Gloucestershire border. It is a parish of interesting and contrasting geology. In the east, the village of Gorsley lies upon a Silurian sandstone – the Downton Castle Sandstone. This stone appears to have been used across the village, which is noted for a number of large quarries and the distinctive honey coloured character of the stone buildings. This contrasts strongly with the village of Linton to the west, which lies along a narrow ridge. This ridge is made up of Devonian sandstones, from which the stone in the village appears to have been sourced. The use of Gorsley Stone in a limited area around the quarry imay prove particularly instrucive of the distances over which people were willing to transport stone.

Interactive map of Linton & Gorsley

Bromyard & Downs

Red Sandstone Chapel, Bromyard DownsThe town of Bromyard lies on the main road between Worcester and Leominster, in eastern Herefordshire. The high land on which the town sits is called the Bromyard Plateau. It is underlain by hard sandstones and mudstones, formed from the erosion of ancient mountains during the Devonian Period.

There is huge variation in the building stones used in the town, ranging from rough cornstone conglomerates – possibly dug from cellars onsite – to fine green sandstones quarried on the Downs and coarse hard wearing grits brought from Bringsty Common, 5 miles away.

Untangling this history is an ongoing challenge.

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