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| Concentric circle patterns of an unknown origin |
When attending the Save Our Greenbelt Coffee Morning in Braithwell, my friend Lindsey from Micklebring asked if I had ever been to The Crags at Edlington Wood. Although I had undertaken a survey of potential RIGS (Regionally Important Geological Sites) in Doncaster in 1997 and resurveyed these for the Doncaster Geodiversity Assessment in 2007, I was not aware of it.
A Google search shows that it contains Scheduled Monuments - Roman settlements and later earthworks - and other enclosures, is designated as a biological SSSI for its ancient woodland, and is also locally listed as a Historic Park and Garden and there is a rock shelter where Upper Palaeolithic flint tools have been found.
Following on from my investigation of the geology and building stones of Clifton, I took advantage of a fine day on 1st May 2025 to explore this and then walk back to Conisbrough via New Edlington, where I hoped to see the New Edlington Brickpit SSSI.
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| Wild garlic in Edlington Wood |
Alighting from the X2 bus from Rotherham at the Broomhouse Lane/North Street stop, I made my way across an open field to a well used path around the northern boundary of Edlington Wood - which is actually privately owned but nonetheless frequented by walkers - and was greeted by wild garlic in full bloom and, a little further east along the path, a burnt out car.
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| A burnt out car |
The path that I followed is set on calcareous mudstones of the Edlington Formation, which is on the downthrown side of a fault that coincides with the alignment of The Crags and I had expected to see a well defined linear feature, as at Barnburgh Cliff.
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| A view of The Crags |
Getting closer to the first outcrop that I saw, I immediately realised that is this location of the rock shelter and, looking at the massive dolomitic limestone of the Cadeby Formation, there is no well defined bedding or bryozoan reefs - as seen at North Cliff Quarry in Conisbrough. These are a feature of the lower Wetherby Member and their absence and the abundance of voids suggests that this could be the Sprotbrough Member.
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| A rock shelter |
Looking at the surrounding landscape, many large blocks of limestone seem to have become detached from the main outcrop and have rotated and slumped to various degrees, which may be related to movement along the fault.
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| Rotated and slumped blocks |
Many isolated blocks, which are covered in ivy and other vegetation, are scattered around the lower slopes as seen in Anston Stones Wood - where the formation of the gorge has led to the undercutting and cambering of these large blocks, which have slid downhill for some distance.
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| A detached block of limestone |
The covering of vegetation and very uneven ground formed by these slipped blocks, which have their edges rounded in many places, made it quite hazardous underfoot and difficult to move around and it was some time before I was able to find a place where I could discreetly obtain a specimen with my Estwing hammer.
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| A view north from The Crags |
Eventually finding a location, the piece that I obtained is crystalline and very open textured, with a couple of small crystal lined vughs. The geological memoir describes the limestone in and around Edlington Wood as having “granular, oolitic and cellular varieties”.
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| A specimen of dolomitic limestone from The Crags |
Returning to the footpath and continuing eastwards, I could see further highly vegetated outcrops with a very irregular outline and what would probably be described as rock shelters, which are probably formed by movement of the blocks and not karst processes.
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| A view of The Crags from the footpath |
The thick undergrowth didn’t make it easy to gain access to these, but it wasn’t too long before I found a place where I could get close without much difficulty and take note of the similar movement and rotation of large blocks.
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| A slumped block of limestone |
In this location, much of the outcrop has quite a different character, with it appearing to be composed of angular pieces of limestone in the form of a breccia, although the covering of moss and algae mainly obscures the surface.
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| A detail of a breccia |
In one place I encountered a vertical rock face, which doesn’t appear to be typical along these crags, and this has a joint plane that separates the body of the limestone from a smaller section that will eventually become detached.
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| A view of brecciated limestone and a fault plane |
I didn’t spend any time looking for evidence of movement along this plane, such as slickensides or displacement of bedding planes, but the small section is composed of breccia and it is therefore possible that this marks the position of the mapped fault.
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| Another view of the brecciated limestone |
On one face of the limestone, I was intrigued to find several markings that comprise a series of concentric circles, which I originally thought must be lichen or another organism; however, when enlarging my photos, they seem to be part of the rock and do not have an organic texture.
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| Another view of the concentric circle pattern in the limestone |
Having completed a brief investigation of The Crags, I again returned to the footpath and continued until I reached an open field where there is a panoramic view to the east. Unknowingly, I was right next to the Roman hut and oval enclosure and when finding another path to get me back to the entrance, I passed other sites that are marked on the Heritage Gateway map, but was completely unaware of them amongst the surrounding trees.
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| A panoramic view across the field to the east of Edlington Wood |
