The Magnesian Limestone escarpment at Clifton |
After spending half an hour exploring the geology of Hooton Cliff along its length, the escarpment was brought to an abrupt end by a fault that brings the Cadeby Formation into contact with the Ravenfield Rock – the uppermost named sandstone of the Pennine Upper Coal Measures Formation (PUCMF) exposed in Rotherham.
The next leg of my journey involved a walk down to Firsby Lane along an extremely narrow public footpath that crossed a field of waist high barley, where I dreamily recalled the opening scene to the film Gladiator.
Looking across the PUCMF strata to the east, which form an undulating landscape, in the distance I could clearly see the village of Clifton, which is set on a part of the Magnesian Limestone that forms a very distinct escarpment.
Continuing along the footpath, where the very sandy soil confirmed that the bedrock was still the Ravenfield Rock, I encountered a female pheasant who was also wandering along this path. I don’t know who was more startled, me or her, but once she had disappeared, I just followed the path until I reached Firsby Hall Farm, where I took photos of a converted barn and an ornate doorway for the British Listed Buildings website.
Just before arriving at Ravenfield Ponds, which were once the fish ponds to the now demolished Ravenfield Hall, I came across a small roadside exposure of irregular current-bedded Ravenfield Rock, a sandstone that I had not seen before.
With my Estwing hammer, I collected a small sample of sandstone from one of the exposures that displays prominent current-bedding, which is fine grained and yellowish in colour; however, the 1947 geological memoir for Barnsley mentions that the Ravenfield Rock often has red staining.
Just beyond the roadside exposure, I then encountered an old quarry where the faces were overgrown and obscured by trees and thick undergrowth, but this is described in the memoir as showing 20 feet of thick, irregular, current-bedded sandstone and in one place a small section of this can still be seen.
After Firsby Brook leaves Firsby Reservoir, which was constructed by the Doncaster Corporation Water Works, it passes under a boundary wall into which an arched opening has been built, before it feeds the Ravenfield Park fish ponds. I could only photograph it at a distance, but it is a reasonable assumption that the sandstone came from the quarry here – as with the stone used in Firsby Hall Farm.
Although further exposures of the Ravenfield Rock have been recorded in the banks of the stream to the west of Firsby, I didn’t spend any time investigating the area around the fish ponds and instead just carried on along Arbour Lane until I reached the public footpath to St. James’ church – another path that was again noticeable for the extremely sandy soil.
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