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| Members of the Sheffield U3A Geology Group at the end of the day |
Following on from a good walk around parts of the Broomhill and Endcliffe Conservation Areas, to photograph a few of the many listed buildings, a few days later I was leading the Sheffield U3A Geology Group around the Shirecliffe Valley – a green space that I had discovered during the early months of the COVID-19 Pandemic lockdown.
The group had reconvened in July 2021, after a break of 17 months, but with our group leader having been suffering with sciatica since our previous outing to Charnwood Forest, we had not been able to undertake a recce of any of the places that had been proposed during our last indoor meeting in January 2020.
Having visited the Shirtcliffe Valley a few times since, at different times of the year, I had managed to find good exposures of the Pennine Middle Coal Measures Formation (PMCMF) along Shirtcliff Brook, the Woodhouse Rock in an old sandstone quarry and a small exposure of the Swallow Wood Coal – as described in this Language of Stone Blog on the 8th, 24th and 27th of January and the 10th of August and 5th of October 2021 – and I thought that these would be suitable for a short half day field trip.
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| The itinerary for the field trip in the Shirtcliffe Valley |
I sent out the usual details of the field trip to the members, but subsequently had the idea of asking Pat Howells of the Friends of Shirtcliffe if she would like to join us, to supplement my knowledge of the geology with her extensive experience of investigating the natural and industrial history of the valley, which once had several small coal mines.
After introducing Pat to the 14 others in the group who turned up on the day, we made our way down to Smelter Wood, where one of our observant members noticed a path that we were walking along was on an exposed bed of the Swallow Wood Coal.
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| A typical Coal Measures cyclothem |
We then looked at a heavily vegetated seam of this coal alongside the path that runs next to Shirtcliff Brook, before I got down into the streambed to demonstrate that the grey mudstone here is slowly turning into clay. It had been my intention to introduce the group to the concept of cyclothems in the Coal Measures, as we would hopefully see on the rest of our walk.
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| Mudstone weathering to yellow clay |
It soon became very obvious that Pat had a lot to say about the valley, showing us the position of various old spoil heaps, covered shafts and other remnants of the coal mining industry, which I would never have noticed. By the time we stopped for lunch, we were running way behind my proposed schedule, but I was just happy to go with the flow.
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| A sample of the Woodhouse Rock (21 mm diameter coin) |
At the old quarry on The Edge, we looked at the rock exposures that can barely be seen in summer and, after collecting a small sample of the Woodhouse Rock (now marked as an unnamed PMCMF sandstone on the map), we continued down to the east entrance of Shirtcliff Wood at Beaver Hill Road, where we all admired the still living stump of a huge black poplar tree and the sections of trunk that have been cut off it.
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| Viewing the remains of the black poplar tree |
Returning to the main path, I realised that a good exploration of the streambanks would have to wait for another day. At 3 o’clock in the afternoon, the sun no longer illuminated the stream banks, one member was grumbling about her feet, another had disappeared to collect a grandchild and the paths, which had been churned up by dirt bikes after a period of heavy rain, were in places difficult to negotiate. The few of us who had kept going to the end, however, briefly stopped for a group photograph to record a thoroughly enjoyable and surprisingly long day.
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| A group member viewing a stream bank outcrop of flaggy sandstone |
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