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| The Collier's Grave |
The day after my visit to Boston Park in Rotherham, to look at the blocks of Rotherham Red sandstone that been excavated during the construction of new reservoirs and retained for possible use to restore historic buildings constructed with this locally distinctive sandstone, such as St. Helen's church in Treeton, I returned to Sheffield to undertake a recce for the next Sheffield U3A Geology Group field trip.
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| The route of the Sheffield Round Walk |
In 2017, except from the leg through the Gleadless Valley to Meersbrook, I had completed the Sheffield Round Walk in stages and had encountered various points of interest: geology, industrial archaeology and, during a couple of later trips to Ecclesall Woods with Linda from our group to help with one of her projects - an attempt to identify the rock formation from which the boulder with rock art is derived.
Since the COVID-19 Pandemic, due partly to the diminishing health matters that had affected the Group leader Paul and other members who had previously organised and led our field trips, gaps had begun to appear in our itinerary and, for our November field trip, I devised a walk that started at Whirlow Quarry Garden in Whirlow and finished at Wood 1 in Ecclesall Woods - a pattern that deviated from our usual circular walk, but which encouraged everyone to use the bus instead of driving to a very popular place where there is limited parking.
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| The planned route for the November geology field trip |
With only the precise location of the rock art being unknown to me, I asked Paul to accompany me on the recce to firm up the route that I had planned and, if required, to add further to the knowledge of the various sites that I had already acquired during my previous visits.
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| The entrance to Whinfell Quarry Garden |
Meeting at the entrance to Whinfell Quarry Garden, which was designed in 1912 by the horticulturist Clarence Elliott to occupy two disused flagstone quarries in the Rough Rock, we firstly had a look at the fine grained paving stones that were presumably supplied from here. These contrast strongly with the coarser grained sandstone used in the walls, which has been brought from elsewhere in Sheffield.
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| Views of Whinfell Quarry Garden |
On previous trips to Leeds, to look at the building stones in the city centre and spend the day exploring Roundhay Park, we had seen several examples of the very coarse grained and often pebbly Rough Rock and this provided a good opportunity to explain the considerable variation that occurs in this very extensive sandstone formation.
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| A specimen of Rough Rock from Fenney Lane |
Leaving by the entrance on Fenney Lane to find the path that would take us down to the path by the Limb Brook, I noticed an exposure of very poorly cemented outcrop of Rough Rock beneath the exposed roots of a tree, which is very fine grained and orange in colour – a characteristic that I had not seen before.
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| The old quarry by the public footpath next to Limb Brook |
The old quarry next to Limb Brook has very well defined alternation between fine grained flaggy sandstone and silty beds, which are deeply weathered. Certain beds are very rich in iron, like the fine sandstone described above, with spheroidal weathering developing along the joint planes.
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| The development of spheroidal weathering |
We quickly made our way down the side of Limb Brook to Ecclesall Woods and then went to have a look at the remains of the Ryecroft Mill and try and find the exposure of the Ran Wood Coal and associated ganister that has been recorded in the stream bank here, but we did not find any rock exposures in the stream bank.
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| The remains of Ryecroft Mill |
Making our way past a small outcrop of sandstone on the southern boundary of Ecclesall Woods, where the sharp junction between the sandstone and underlying mudstone is probably a crevasse splay, we didn’t stop at the ochreous spring. We both knew this well from previous visits and continued past an old Q-pit up past the bird sanctuary and carried on until we reached the J.G. Graves Discovery Centre, where we had lunch.
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| A crevasse splay and the site of a Q-pit |
After lunch, we took a public footpath to Wood 2, where there are further Q-Pits, an old ganister quarry that is now filled with water and known as the Collier's Pond, before continuing to the Collier’s Grave – which marks the place where George Yardley died in 1786, when the cabin that he lived in beside his charcoal hearth caught fire.
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| The Collier's Pond and Collier's Grave |
Continuing to another old ganister quarry in Wood 3, I obtained a couple of samples of greyish coloured and very dense fine grained sandstone from the waste, which contain traces of carbonised wood and are probably ganister, but they lack rootlets that are very commonly seen.
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| Specimens of ganister |
From here, we headed off to find the rock art, comprising a large boulder with cup and ring markings, which is considered to be probably Neolithic in date. To finish our recce, we continued to the Dobcroft Road entrance to the wood, passing one of several streams that has brought down quite large blocks of sandstone from the higher ground to the north.
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| Rock art in Ecclesall Woods |
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