A Geological Recce of Burbage Valley

 

Burbage Quarry

 

My day out to Doncaster on 16th November, to briefly explore Bennetthorpe and to visit Hyde Park Cemetery, proved to be the last of 2024 and, having spent the winter months trying to catch up with my travels in my Language of Stone Blog, I was glad to finally get out again on 22nd February 2025 – on a recce for a Sheffield U3A Geology Group field trip to Burbage Valley.

 

The Ordnance Survey map of Burbage Valley

 

For several months, I had not been happy with the way that the group had been operating – especially the behaviour of a member who had been acting as the “co-ordinator and not geologist”, following the medical problems with the group leader - and I made the decision to leave the group after a set-to in January; however, I had previously arranged with John and Trish, who had helped me with the trip to Ilkley Moor the year before, to accompany them on their recce and point out the main points of geological interest on their walk. 

 

The geology of Burbage Valley and the surrounding area

Back in 1995, when assessing the geotourism potential of the RIGS (Regionally Important Geological Sites) in the Peak District National Park, I surveyed several sites in and around the the Burbage Valley and it wasn't until 2015 that I returned to have another look at Carl Wark, Higger Tor, Burbage Rocks and Burbage Brook.

 

Sphagnum moss at a spring near Upper Burbage Bridge

I noted the very coarse grained deltaic sediments of the Chatsworth Grit, black shales from the Marsden Formation, peat from the Quaternary Period and spring lines, which were emphasised by the presence of Sphagnum moss and other bog loving plants – all of which I thought would make interesting stopping points on a field trip and had raised this at a couple of meetings when itineraries for the year were discussed.

 

Notes from a field trip led by Duncan Hawley of SAGT

 

John and Trish had recently attended a field trip organised by Duncan Hawley of SAGT (Sheffield Area Geology Trust) back in 2019, which highlighted the history and industrial archaeology of the area, and they wanted to repeat this for the Sheffield U3A Geology Group.

 

Longshaw Lodge

 

On the Saturday that we undertook our recce, the car park at the Longshaw Estate was completely full and we had to use the Wooden Pole car park at the south end of the estate, which enabled me take another photo of Longshaw Lodge for the British Listed Buildings website.

 

An unfinished stone trough

 

Our first stop was at the southern end of the old Burbage Quarry, which was cut into the Chatsworth Grit that forms Burbage Edge. Although millstones were the principal product here, there is an unfinished stone trough that was abandoned after it had developed a large crack.

Drill holes to accommodate plug and feathers wedges

In several places, loose blocks show drill holes, into which plug and feathers wedges were inserted to split massive blocks of stone into smaller sizes, from which the millstones were made. Unfinished millstones are scattered around the quarry, which reflects the extremely rapid decline in the industry due to the introduction of steam powered mills, the use of carborundum for making grindstones and a changing taste for eating white bread.

 

A discarded millstone

 

We stopped for our lunch in the part of the quarry, which is popular with rock climbers, where a large rock fall occurred in November 2023 and destroyed some of the climbing routes. Due to the instability of one of the remaining sections, the Eastern Moors Partnership have since dislodged loose blocks by a process known in rock climbing circles as trundling.

 

The rock fall at Burbage Quarry

 

Here, I pointed out to John and Trish how the section of Chatsworth Grit changed from being massively bedded in its lower part to much thinner flaggy beds in the uppermost part, where the cross-bedding is highlighted by sub-aerial weathering.

 

A quarry face showing massive and flaggy beds

From 1941 to 1944, during WWII, the Burbage Valley was widely used for military training by many units and very many of the massive loose boulders below the quarry show bullet holes and damage caused by mortar shells. In particular, uphill assaults were practised here and this explains why the bullet holes are seen on only one side of the rocks, where the targets were set up.

 

A large block of Chatsworth grit with bullet holes

After finding a few more examples of rocks damaged by ammunition, we made our way along the marked public footpath to Carl Wark and stopped briefly at the Grade II listed packhorse bridge (c.1750) over Burbage Brook, which I also photographed for the British Listed Buildings website.

 

The packhorse bridge

A short distance downstream from the bridge, the last point of interest was the stream bank exposure of black shale, which is the only exposure of the Marsden Formation that I have seen along Burbage Valley, where the bedrock is covered with head and some peat. 

 

The outcrop of shale along Burbage Brook

 

The geological map shows that the Verneulites sigma Marine Band occurs in the vicinity, but there is nowhere where the outcrop can be accessed without standing in the brook with waders, to see if it contains goniatite fossils. 

 

Thin beds of sandstone laid down by turbidity currents

 

We had to be content with viewing the outcrop from the opposite side of Burbage Brook, but we could still see that the shale contains a few very thin beds of sandstone, which were deposited by turbidity currents generated by slumping of sediment forming the delta front. Having identified most of the points on Duncan Hawley’s sketch, we made our way through some boggy ground back to the main path and headed back to the car park.

 

A view of Carl Wark (L) and Higger Tor (R)