Sunday 23 October 2022

A Walk Along the Porter Brook

 
The road bridge at Hangingwater Road

Arriving at the bridge over the Porter Brook on Woodcliffe, less than 100 metres downstream from its confluence with the Mayfield Brook, the first thing that I noticed was the deep orange colour of the river bed – the result of the microbial weathering of iron minerals in the shales between the Redmires Flags and the Rough Rock. 
 
Ochreous deposits on the riverbed of the Porter Brook

Having spent just over two hours exploring and photographing historic buildings in Ranmoor and Fulwood, this reminded me of the geology that I would encounter, when following the course of the Porter Brook down to Hunters Bar – based on my experience of previously walking down from Ringinglow and exploring the area with the Sheffield U3A Geology Group. 
 
The bridge over the Porter Brook at Woodside

Quickly walking down past Forge Dam, I took a diversion past various stone built remains of goits and sluices to find the Grade II Listed monument to Thomas Boulsover, which was built in 1929 on the north side of Wire Mill Dam. 
 
Miscellaneous structures along the Porter Brook

Although a photo had already been contributed to the British Listed Buildings website, I was interested in seeing this monument to the creator of Sheffield Plate. Having passed the sculpture by Richard Perry outside the central library in Sheffield very many times, which I know more for the green staining to the Portland stone plinth than Thomas Boulsover himself, I wanted to learn a bit more about Sheffield’s industrial history. 
 
The Thomas Boulsover monument
 
Stopping briefly to photograph the Grade II Listed No. 8 and Nos 4 and 6 Ivy Cottages, where the overall character of the walling stone looks quite different and contrasts with the bricks used to build No. 2, I continued east along the path that runs beside the brook.
 
Views of Ivy Cottages

The Porter Brook has cut down through the Pennine Lower Coal Measures Formation into the Rough Rock here, which is exposed by the constant flow from a spring on the south side of the valley and where generally flaggy beds are clearly seen. 
 
A small exposure of the Rough Rock
 
Continuing along the path to the Hangingwater Road bridge, built c.1800, I stopped to take a few more photographs for the British Listed Buildings website, before going to investigate the various rock exposures in the river bank downstream. 
 
The east elevation of the Hangingwater Road bridge

I immediately encountered another extremely ochreous small tributary stream – this time probably related to the drainage from shallow coal mine activities, with microbial weathering of the mineral pyrite that is often associated with coal seams.
 
An ochreous tributary of the Porter Brook

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