Sunday, 27 February 2022

A Walk From Wentworth to Elsecar

The Needle's Eye at Wentworth

In the second week of June, having explored Wyming Brook and the Rivelin Valley in Sheffield, where I encountered various strata in the Millstone Grit Group, my next day out entailed a circular walk from Wentworth to Elsecar.
A map showing the area between Wentworth and Elsecar

Over the years, I have visited the village of Wentworth, one of my very favourite places, numerous times and I have been to Elsecar Heritage Centre a few times, but I had never explored the countryside between them on foot.
A view of the Needle's Eye from Cortworth Lane

Arriving on the No. 136 bus from Rotherham, with a drastically reduced service since my last visit in 2019 that necessitated some careful planning, I headed along Cortworth Lane and turned up Coaley Lane and continued up the hill until I reached the Needle’s Eye, which is built on Kent’s Rock – a Pennine Middle Coal Measures Formation sandstone that forms a considerable escarpment in places, from King’s Wood to Rawmarsh.
A geological map showing the position of the Kent's Rock

I had visited the Needle’s Eye a couple of times before it was cleaned and, except to take a set of general photos to update my existing record of its condition, I didn’t spent much time further examining it and continued along the escarpment towards Elsecar.
Masonry beneath the arch of the Needle's Eye

After a couple of hundred metres, I had a view of the new Holy Trinity church, the old Holy Trinity church and the vernacular buildings to the north of Main Street in Wentworth village and I was surprised to see the distinct scarp and vale topography, which I had not seen before.
A view of Wentworth from the escarpment of the Kent's Rock
The ridge of Kent’s Rock has an elevation of only 145 metres, but there are panoramic views from the west to the south and I could easily make out the ridge of Grenoside Sandstone forming the skyline at Greno Woods and, with the aid of the zoom lens on my Canon G7X Powershot camera, I could see other notable landmarks – including Keppel’s Column and the Herdings Twin Towers.
A panoramic view from the escarpment of the Kent's Rock

Continuing towards Elsecar, the public footpath dropped down into the valley formed by Knoll Beck and another panoramic view of the landscape, on which Hoyland and Jump have been developed, opened up to the north-west.
A panoramic view of Hoyland and Jump

Looking at the lie of the land in front of me, I could just about discern the general strike and north-easterly dip of the strata that is typical of the Coal Measures strata in this part of South Yorkshire but, as the British Geological Survey 3D map viewer shows, faulting in the area makes it difficult to interpret the landscape here.
Following the path down through the meadow to a small area of woodland outside Elsecar, I noted very many subangular fragments of what looked like ironstone exposed in the ground alongside it, which had no obvious bedding and is probably waste material from the former Elsecar Ironworks.
Fragments of ironstone alongside the public footpath

I don’t know the local source of the ironstone, which was mined locally along with coal since the C14, but the 1947 geological memoir describes a quarry in the Kent’s Rock at Upper Haugh as having beds that include many ironstone nodules and pass into distinct ironstone bands in places.
Specimens of ironstone

An Exploration of the Rivelin Valley

Chatsworth Grit in the Rivelin Valley

Arriving at the end of the path alongside Wyming Brook, my plan was to follow Wyming Brook Drive to the west entrance to the nature reserve on the main A57 road, from where I would catch the No. 257 bus back to Sheffield.
A stream cutting into the head

Having walked for a kilometre, with only a small stream cutting into the head providing any geological interest, I arrived at a U-bend in the track, where a stone bridge crosses a small tributary of the Rivelin Brook and went to investigate the various rocks in the streambed.
A tributary of the Rivelin Brook

Looking at the British Geological Survey map, the rocks at this point are assigned to the Marsden Formation, which is found immediately below the Chatsworth Grit and is composed of sandstone and mudstone/siltstone, which are distinguished on the map but not named.
A geological map showing locations of samples

Many of the rocks that I could see were small rounded boulders that I presumed to be Chatsworth Grit, as I had seen along the length of Wyming Brook, but I obtained a sample of well bedded and relatively angular sandstone with my Estwing hammer.
A specimen from the Marsden Formation

Looking at the specimen with the naked eye, it is light brown in colour and contains distinct laminations, with an abundance of mica along the bedding planes, with the weathered surface developing a blackened appearance and an orange rim penetrating the fresh body of the sandstone. Viewed through a hand lens, it is very fine grained and contains specks of a dark mineral that is generally converted into orange iron oxides/hydroxides.
An outcrop of Chatsworth Grit
Continuing along the track, which follows the outcrop of Chatsworth Grit, an extensive and easily accessible exposure provided an opportunity to obtain a sample that was less weathered than those that I had collected at Wyming Brook.
An outcrop of Chatsworth Grit

Again, this proved very difficult and the two small specimens that I collected were both weathered to a certain degree and I could break them with my fingers. The larger piece is coarse grained and slightly pink in colour, with grains of white weathered feldspar and flecks of oxidised iron bearing minerals and the smaller one is very iron stained.
A specimen from the Chatsworth Grit

Crossing over the Rivelin Brook, which flows down from the moors into the Rivelin Dams, the bridge is constructed of squared and rock-faced blocks of Chatsworth Grit, with the large coping stones being quite crudely shaped and tooled.
The bridge over the Rivelin Brook

With the Chatsworth Grit being very suited to use for civil engineering purposes, quarries in the immediate vicinity would have been opened specifically for the construction of the dams and associated structures and some of these are visible to the immediate west of Rivelin Rocks.
The location of old quarries above the Rivelin Dams

I arrived at the bus stop, having walked only 5 kilometres and with at least 25 minutes to wait before the hourly No. 257 bus arrived, so I just decided to walk back towards Sheffield to make the most of a warm sunny day.
The spillway at the Rivelin Dams
Stopping only to look at the spillway at the Rivelin Dams, I progressed at a good speed and checked the time at each bus stop, which seemed to be approximately every 500 metres. I calculated that I would have more than enough time to get to my final stop, only to discover that the distance I had to walk was 1500 metres and the bus overtook me, running 5 minutes early, when the bus stop was in sight.
A view along the A57

Cursing my bad luck, I continued until I found a shady spot and stopped for ten minutes to finish my packed lunch and have a drink before starting off again up the hill, where I was very surprised to see some crozzle used to top the boundary walls.
A boundary wall topped with crozzle

With the midday sun beating down and the incline up the A57 starting to take its toll on my legs after a good walk, I finally arrived at the Valleyside Garden Centre, which I later discovered is sited in the old Bell Hagg Quarry – but I had done enough exploring for one day and I was just glad to sit down on the grass.

My exploration of Wyming Brook and the Rivelin Valley

Monday, 21 February 2022

The Chatsworth Grit at Wyming Brook

Wyming Brook

In the first week of June 2021, having spent the previous Sunday exploring the Sheffield Board Schools in Netherthorpe, Crookesmoor and Broomhill and the geomorphology in this part of Sheffield, my next day out was to Wyming Brook.
Wyming Brook and the Rivelin Dams

Located just inside the Peak District National Park, on the south side of the Rivelin Valley, I became aware of it when looking for places to visit during the summer, after researching the Carbrook Ravine Nature Reserve on the Sheffield and Rotherham Wildlife Trust website.
The Rivelin Valley is not a part of Sheffield that I know well, having only visited the Rivelin Rocks to look at the Chatsworth Grit when surveying the RIGS (Regionally Important Geological Sites) in the Peak District National Park and visiting the Rivelin Glen Quarry in 1995, with a short walk along part of the Rivelin Valley Trail in 2014.
The clock tower and 'Oak Sculpture'
Alighting at the terminus of the No. 51 bus from Sheffield at Lodge Moor, before heading west along Redmires Road, I was curious about the clock tower that was once part of the Lodge Moor Hospital, initially built following the smallpox epidemic of 1887-1888, and was delighted to see the stainless steel ‘Oak Sculpture’ by Mike Johnson.
A ridge of the Rough Rock seen from Redmires Road

On the approach to the head of Wyming Brook, to the south of Redmires Road, the topography is seen to rise in steps, which marks the position of the Rough Rock, a coarse grained sandstone that forms part of the uppermost formation in the Millstone Grit Group.
The path leading to the stepping stones at Wyming Brook

Taking the first available path down to Wyming Brook, the steep slope contains many small blocks of gritstone embedded in rock debris and soil, which form a deposit known as head and leads to a relatively open and flat area of ground, where stepping stones cross the brook.
An 'edge' formed of Chatsworth Grit

Following the path alongside the brook, after a short distance the stream gradient steepens noticeably, with the Chatsworth Grit on the opposite bank forming a distinct ‘edge’ and, hoping to obtain my first sample of this very coarse sandstone, I crossed the footbridge with my Estwing 20 oz brick hammer in hand.
An outcrop of Chatsworth Grit

As I had discovered during one of my geological field trips at Nottingham University, when examining the granite tors of the Cornubian Batholith in Cornwall and Devon, where there are no obvious ledges or angles, it is not very easy to break off the rock from massive outcrops like this.
Small samples of coarse grained Chatsworth Grit

Having found a place where I could chip off a small piece, the coarse grained sample that I obtained was very weathered – a result of the deterioration of the mineral microcline feldspar in the gritstone. This constitutes a considerable proportion of the very coarse deltaic sandstones that were derived from granitic highlands, which lay to the north during the Carboniferous Period.
Blocks of Chatsworth Grit in Wyming Brook

Making my way further downstream, the brook passes through a block field, consisting of large slipped blocks of gritstone, similar to those seen along the eastern boundary of the Peak District National Park, as at Burbage Edge, where Burbage Brook passes down through Padley Gorge.
A view of the block field at Wyming Brook

In many places, the muddy path has been laid with roughly square or rectangular blocks, but for much of the way from the top to the bottom of the course of the brook, I had to walk over blocks and natural rock debris that in places weren’t easy to traverse - especially where springs were emanating from the slopes above the brook.
A spring flowing across the path

Sometimes, the gradient of the brook lessens to form pools, where the rock fragments in them are stained with orange iron oxides and hydroxides, which are derived from the Chatsworth Grit - a characteristic of most of the Upper Carboniferous sandstones in South Yorkshire.
Iron staining in the stream bed

From start to finish, where I took the path heading west past the Rivelin Dams, I had walked less than 800 metres down quite a steep sided wooded valley, but with a descent of 100 metres and all along the way, large slipped blocks litter the surrounding slopes.
A wooded slope with slipped blocks

Apart from providing an excellent example of the erosional and depositional features associated with the Chatsworth Grit edges, it must be the most spectacular landscape that I have encountered to date during my exploration of South Yorkshire.
A large slipped block of Chatsworth Grit

Sunday, 20 February 2022

Grenoside Sandstone at the Octagon

Silty beds in the Grenoside Sandstone

On a day that I had set out to explore the Sheffield Board Schools at Netherthorpe, Crookesmoor and Broomhill, I also encountered several hills of various steepness that reflected the strike and dip of the underlying Pennine Lower Coal Measures Formation sandstones, along with the intervening vales forming on the mudstones.
A vale between the Loxley Edge Rock and the Greenmoor Rock
When preparing my route, as I had done for my walk around Attercliffe and Darnall a month earlier, I had referred to the list of publicly accessible Local Geological Sites on the Sheffield Area Geology Trust (SAGT) website – one of which was at the Octagon Centre at Sheffield University – and I decided to go and investigate it on the walk back to Sheffield city centre.
Local Geological Sites accessible to the public in Sheffield

Having spent several months working as a geologist at the nearby Weston Park Museum and knowing the curator of geology well, through my involvement with the South Yorkshire RIGS Group, I was very surprised that I hadn’t known about this site before.
The outcrop of Grenoside Sandstone at the Octagon Centre

According to the 1957 Geological Survey of Greet Britain Memoir, the Grenoside Sandstone is, as a rule “remarkably micaceous and fissile, in places splitting into thin flat plates bounded by bedding planes which are covered in large plates of mica”.
A description of the Grenoside Sandstone in the geological memoir

The accompanying British Geological Survey map shows the actual outcrop of the steeply dipping Grenoside Sandstone to be slightly to the north-east of the Octagon Centre, as recorded by SAGT, but the sandstone seen here certainly has these characteristics.
A geological map of the area around the Octagon Centre

The exposure is no more than 15 metres long and 2 metres high, but it displays a section of predominantly thin beds of fine micaceous sandstone, which is pervaded by persistent thinly spaced joints that breaks the rock into small irregular lumps.
Joints in the Grenoside Sandstone

Although I had my Estwing hammer with me, I had no need to use it when collecting a sample and, in places, the sandstone passes into much finer grained siltstone beds, which are highly laminated and can easily be pulled apart with the fingers.
Fine sandstone and siltstone at the Octagon Centre

In places like Grenoside and Norton, where it occurs in thicker beds, it has been used locally for building stone but the stone found here, which has been disrupted by the folding that formed the Don Monocline, is unsuitable for this. The sample that I collected is fine grained in texture, grey/light brown in colour, with iron banding and very micaceous on the bedding planes.
A sample of Grenoside Sandstone

The Broomhill Board School

The Broomhill Board School
Finally arriving in Broomhill, having walked up the long hill from Crookesmoor Board School, I immediately went in search of Broomhill Board School, the final Sheffield Board School that I had planned to see during a good walk in Sheffield.

The approach along Beech Hill Road

Approaching the school from the west, the semi-circular end and the flat roof looked like an Art Deco cinema and unlike any of the other 18 schools that I had seen on my travels to date, not including the Central Schools at Leopold Street. These odd looking features are actually a staircase tower, which was added in 1880, with the rooftop playground being created in 1943 after a fire destroyed the original second floor and pitched roof.
The north elevation

The school dates to 1873 and was the second board school built after the Education Act of 1870 and, following the demolition of the Newhall Board School in 1970, it is now the oldest remaining board school in Sheffield.
A view from the east

Continuing along Beech Hill Road, the north elevation is seen to possess recessed arched windows, with herringbone masonry and trefoils, which would become a prominent feature of CJ Innocent’s work and the original drawing shows that it was originally no less ornate than any of the other schools that he designed when with the practice Innocent and Brown.
The Sheffield School Board crest
From the start, space was an issue with the school and it was extended in 1870 and 1880, as well as 1887, but I didn’t spend much time looking at the various buildings, including the caretaker’s house. Instead, I just photographed a few of the details that I could see, including the Sheffield School Board crest and the inscriptions that marked the entrances for the girls and infants.
An inscribed gate pier
Although I didn’t examine the masonry in any detail, I didn’t see anything to make me think that the usual Crawshaw Sandstone had not been used for the walling stone; however, the inscribed gate piers didn’t seem to be the gritty sandstone that features in most of the schools and the stone for the crest didn’t look uniform in colour or texture - as I would expect from the massive Derbyshire or West Yorkshire sandstones, which were generally used for dressings.
The entrance for infants

Having considerable experience of stone identification and matching, I thought that identical stone had been used for the original building and extensions and I was very surprised to discover that, according to the book Building Schools for Sheffield by the Victorian Society, Dunford Hill stone has been used for walling stone.
The location of potential sources of building stone

A short article on the Sheffield Area Geology Trust website suggests that Dunford Hill refers to Dunford Bridge in the north-west of Barnsley where the Huddersfield White Rock was quarried but, although this is apparently used for ashlar at St. James’s church in Woodhouse, dated 1878, I have not yet examined it closely.
The caretaker's house
It is also states that Handsworth stone is used for dressings, which again I found surprising because, although the quarries – which marketed their product as ‘bluestone’ - have disappeared and no rock outcrops can be seen in the area, nearly all of the historic buildings that I have seen in Handsworth have developed a very distinct ‘ginger nut’ hue when weathered – a characteristic that is not apparent at Broomhill Board School.
A view from the south