Sunday, 29 August 2021

A Walk Down Moorgate in Rotherham

The old Vestry Offices on Moorgate Street

Having had a good look at the Rotherham Red sandstone in the old quarries in Canklow Wood and Boston Park, I started off on my walk back to Rotherham and stopped briefly at Moorgate Cemetery, to look at a few architectural details on the lodges and adjoining walls.
The lodges at Moorgate Cemetery
Arriving at Moorgate Road, I carried on down towards Rotherham town centre, passing a few substantial houses built in Rotherham Red sandstone and went down the driveway of Moorgate Hall, a substantial Grade II* Listed C17 house, to get a couple of photos.
Moorgate Hall

Moorgate is an affluent area of Rotherham and, although not listed, there are several large Victorian houses that have architectural interest, for the use of various materials other than Rotherham Red sandstone – including No. 25 Moorgate Road, where Permian dolomitic limestone has been used for the dressings.
Dolomitic limestone dressings at No. 25 Moorgate Road

Carrying on down to Moorgate Street, I briefly paused outside Rotherham Town Hall, which is built in artificial stone that looks very like Portland limestone from a distance, to take a photo of the Walker cannon – an example of the workmanship that enabled the company to supply 79 of the 105 guns aboard HMS Victory.
The Walker cannon
Just a bit further down Moorgate Street, I stopped again to photograph the unlisted old Vestry Offices, which needs some maintenance. I have always thought that it is an interesting building, but I don't know anything about its history.
The old Vestry Offices on Moorgate Street
Although Rotherham Red sandstone has only been used for the dressings on a brick building, I just like the details – especially the lettering above the door and the floral details on the high level pediment, which records its construction in 1894.
A detail of the old Vestry Offices

Coming finally to the top of High Street, I then headed down Church Street and, with the sun still shining brightly, I took advantage of this to take a few more photographs of the south elevation of Rotherham Minster
The tower and spire of Rotherham Minster

Boston Park in Rotherham - 2021

A cast of a Lepidodendron

Carrying on from my exploration of the geology of Canklow Wood in Rotherham, I made my way to Boston Park, where I was very interested to see what changes, if any, had taken place since my last visit in 2018.
Work on the new reservoir
In the interim, there had been plans by Yorkshire Water to renew the reservoir at the rear of the park and, at one time during the negotiations with Rotherham MBC, there had been talk of spending money on the improvement of the park.
Exposed Rotherham Red sandstone

Finding that the old reservoir was being reconstructed without altering its position, I was interested to see that excavations had exposed sections of Rotherham Red sandstone and I wondered if any blocks of stone had been retained, as I had discussed with the manager of Green Spaces a couple of years earlier.
The fenced off steps to the south-east entrance

The steps at the south-east entrance to the park were fenced off, so I made my way into the park by an alternative route and wasn’t surprised to see that a large stretch of the old quarry face had been left untended and become overgrown, with shrubs obscuring some of the lower parts.
An obscured quarry face at the east end of the park

In mid-February, with the trees bare of leaves, I could still see patches of rock where the ivy had not yet covered the old quarry face, which was an improvement on the last time that I saw it in 2018, when I couldn’t see anything.
A view of the area once occupied by the bowls pavilion

Moving closer to the old quarry face that was once partly obscured by the bowls pavilion, I couldn’t see any signs of the conglomeratic beds of ironstone pellets and, except for a section where the upward change from massive to flaggy sandstone can be seen, there were no good exposures.
An exposure of massive and flaggy beds

Moving further along to the doorway from the College of Jesus, although this seems to be the only part of the quarry face where any attempt has been made to cut back the ivy, its growth is generally unconstrained and many interesting sedimentary structures are now covered.
The doorway from the College of Jesus
In places, however, there are glimpses of trough cross-bedding in sandstones that are composed of laminated beds that alternate from red to yellow. There are still probably enough exposures to enable the site to be used for educational purposes, although this would benefit greatly from the regular clearance of the ivy.
An example of trough cross-bedding

Continuing along the path towards Boston Castle, although many of the rock exposures are in the shade and not that easily accessible due to the planting and walling here, they are relatively free from ivy and many features are visible.
A good exposure of ivy free Rotherham Red sandstone

On the other side of the path, although now fenced off, a walkway passed through the copse like feature that is set on a landscaped mound of land. The walkway is lined with slabs of rock that contain both ironstone pellets and fossils of Carboniferous trees, which have been obtained from the conglomeratic beds that were not suitable for building stone.
Slabs with Carboniferous tree fossils and ironstone pellets

Moving up to the parking area, where there was once an excellent section through the soil horizon that has formed on the Rotherham Red sandstone, there is now only a thick mass of ivy that could easily have been kept under control.
The car parking area

The only addition to the park since I have first known it is a large sculpted block of stone that has depictions of wheatsheaves and a plough, scythe and rake, which was salvaged when the Corn Exchange in the town centre was demolished.
A stone salvaged from the Corn Exchange

Boston Park in Rotherham

An exposure of Rotherham Red sandstone in December 2011

When I first visited Rotherham more than 40 years ago, while visiting friends that I had met at Nottingham University, where I was studying for a degree in geology, I was shown the Grade II Listed Boston Park
Boston Park in 1994

I was particularly impressed by the extensive exposure of Rotherham Red sandstone, the variety of Mexborough Rock that gives the historic buildings of Rotherham and many of its surrounding villages a locally distinctive character.
A promotional event by the South Yorkshire RIGS Group

Many years later, in 1994, when the recently formed South Yorkshire RIGS (Regionally Important Geological Sites) Group selected a handful of sites for their first ‘promotional fortnight’ - to introduce the general public to the county’s geology – it was an obvious choice, along with Roche Abbey in Rotherham.
RIGS selection in South Yorkshire

A couple of years later, after the RIGS Group had undertaken surveys in Rotherham and Barnsley, to add to geological surveys previously completed in Sheffield – but with Doncaster not yet joining in with the initiative – Boston Park was selected as the only ‘5 Star Site’ and it was proposed by Rotherham MBC Forward Planning as Rotherham’s first geological nature reserve.
Boston Park in December 2011

This took into account the adjoining ancient woodland in Canklow Wood, with its Scheduled Monument, the Grade II Listed Boston Castle and the nearby Moorgate Cemetery – all of which together were considered to have very high heritage, aesthetic and educational value.
A bed of ironstone pellets
Apart from a spectacular rock face, where conglomeratic beds of ironstone pellets could clearly be seen, along with the large scale cross-bedding and various other sedimentary structures, I identified many points of geological interest in the park.
The doorway from the College of Jesus in 2009

In addition to the doorway from the College of Jesus, these include a basalt grindstone from an old windmill used as a base for the ‘directional pointer’, a crocketted finial left over from the restoration of All Saints church and borders to the various paths through the park marked out by lumps of white gypsum.
Gypsum border markers

For many years, I campaigned to get a leaflet produced – like the well received Anston Stones Wood Geological Trail – but changes to the staff in the forward planning department at Rotherham MBC led to a loss of interest in the geology of the town, with the South Yorkshire RIGS Group eventually grinding to a halt.
A closed and fenced off walkway left to deteriorate

Although Boston Castle has been since restored and reopened, albeit underused, Boston Park itself has been left to decay, with the closure of the bowling green and the removal of all of the flowerbeds. Various stone walls and steps have fallen into a state of considerable disrepair, areas are fenced off and many of the interesting features have been removed, buried or vandalised.
The vandalised directional pointer

With Rotherham MBC delegating their statutory responsibilities, with respect to geological conservation, to volunteers at the SAGT (Sheffield Area Geology Trust) – comprising mainly retired teachers and university academics who don’t even live in Rotherham - I gave up trying to put some good ideas into practice and the best exposure of Rotherham Red sandstone has just been left to become overgrown.
The site of the old bowls pavilion in August 2018

Saturday, 21 August 2021

Geology in Canklow Wood - Part 2

Small scale deformation in the Rotherham Red sandstone
Continuing with my exploration of the old Rotherham Red sandstone quarries in Canklow Wood, I came across several more examples of massive beds of sandstone with large scale cross-bedding, which record the movement of sediment in a large river channel.
Flaggy beds above massive sandstone

I could also see that the upper parts of these were composed of thinner flaggy beds, which can often be seen in the upper parts of exposed rock outcrops, where the surface weathering processes that lead to the formation of the soil horizon are operating.
Flaggy beds above massive sandstone

Looking closer, the massive sandstone is seen to pass upwards into the thinner planar beds, without any discernable break in the deposition of the sediment. They also have low angle cross-lamination and are consistent with deposition with in the upper flow regime of the channel, where the rate of flow of the water is greater.
An abrupt change from massive to flaggy sandstone

In places, there is a very abrupt change from massive beds with large scale cross-bedding to finer grained, thin bedded flaggy sandstone, where there is a very distinct break in the bedding, which marks a period of erosion.

Diffferential weathering produces overhangs

Looking around the old quarry, various other interesting features can be seen, including graded bedding in the more massive beds, with the finer silty sediments being differentially weathered to leave distinct overhangs in places – features that have appeared in the faces since quarrying ceased in the C19.
Cross-bedding and differential weathering

These old quarries were identified as a Regionally Important Geological Site, when surveyed by the South Yorkshire RIGS Group back in 1997 and, although they never received the same attention as the nearby Boston Park, they contain a wide range of sedimentary structures – including trough cross-bedding, which is associated with the migration of large sub-aqueous sand dunes along the river channel.
Trough cross-bedding in massive sandstone

Having had a good look around the various exposures of this red variety of Mexborough Rock, where I collected a couple of specimens of sandstone that show various degrees of red colouration, I made my way up to the path that runs along the escarpment.
Specimens of Rotherham Red sandstone

Looking down through breaks in the covering of trees, I could see glimpses of rock in other quarry faces that were not easily accessible across mounds of waste stone and then continued along the path through the Canklow Hill earthworks, which is a Scheduled Monument, but seeing no obvious evidence of these I carried on to Boston Park. 
A view of an overgrown quarry

Thursday, 19 August 2021

Geology in Canklow Wood - Part 1

A detail of ironstone pellets and casts

Having got 2021 off to a good start with a further exploration of the geology of Shirtcliff Wood and Bowden Housteads Wood, on the first day of February – coinciding with week 47 of the COVID-19 Pandemic – I took advantage of a cloudless day to explore Canklow Wood in Rotherham.
A distant view of Canklow Wood

This ancient woodland occupies a large part of a distinctive escarpment to the south of Rotherham, which is capped by the Rotherham Red variety of Mexborough Rock that runs with a strike NNW-SSE down to Aston and Todwick.
A geological map showing the position of Canklow Wood

The Rotherham Red sandstone was once extensively quarried along its length, with the old workings clearly visible on LIDAR over a distance of more than a kilometre but, apart from the area that was transformed into Boston Park in 1876, rock outcrops aren't that easy to access.
A LIDAR map showing old quarries

While undertaking the survey of RIGS (Regionally Important Geological Sites) back in 1996, I briefly visited some of the quarries that were still accessible and in 2010, when the site was resurveyed after the South Yorkshire RIGS Group was incorporated into the Sheffield Area Geology Trust (SAGT); however, when searching for these more recently from the top path, I found that the trees had grown so much that I completely lost my bearings.
Canklow Wood in 1996 and 2010

This time, having investigated the entrances and paths that are marked on various maps, I entered the wood on the West Bawtry Road, near to Canklow roundabout, and continued up a well worn track that is embedded with innumerable irregular blocks of red sandstone.
The track up to the old quarries

Even with the trees bare of leaves, it wasn’t easy to navigate around the upper slopes, which is criss-crossed by various paths and much of the ‘hills and holes’ landscape left behind after the quarrying ceased is wooded with dense undergrowth.
The approach to the old quarries

Eventually finding one of the two areas in Canklow Wood that are now described as Local Geological Sites, there were enough good outcrops to enable me to find a range of sedimentary structures in the Mexborough Rock that I had not encountered before. 
Large scale cross-bedding

The British Geological Survey describes the setting of this rock as fluvial in origin, with the sediments ranging from coarse to fine-grained and, in very many of the outcrops, large scale cross-bedding - reflecting deposition in a large channel - can clearly be seen from a distance.
Looking closer at this massive sandstone, smaller scale finer cross-bedding is also visible and, although I didn’t see any of these in situ, I noted that some of the discarded blocks have concentrations of ironstone pellets on their bedding planes.
A detail of the bedding plane on a loose block