Greenmoor Rock at Parkwood Springs

 

A geological section at Neepsend Brickworks

The area around Burngreave is not particularly rich in historic buildings and, to make a decent walk, I decided to further explore Parkwood Springs, a part of Sheffield that a late colleague and friend – Gaynor Boon from Sheffield Museum – had mentioned many times, but which I had only briefly visited back in 2016 and had strangely overlooked for this Language of Stone Blog.

 

The Bird and Boy sculpture on Rutland Road

Entering the site at the Boy and Bird sculpture by Jason Turpin-Thomson on Rutland Road, I didn’t have a map with me and, after making my way around the mountain bike trail, I continued through the re-established heather covered heathland towards the old Sheffield Ski Village.

 

A view along a path heading north in Parkwood Springs

Once on the rising ground beyond the woodland, there are views across the Don Valley to Walkley and further along the path, panoramic views of the high ground upon which the outer ring road is set – with landmarks such as the Herdings Twin Towers being visible.

 

Panoramic views from Parkwood Springs

I then encountered various small outcrops of Greenmoor Rock in the hillside above the path, where the dip of the strata is several degrees to the south and forms part of the Don Monocline – a major SW-NE trending structural feature that the Lower Don Valley follows beyond Mexborough, which is 20 km away as the crow flies.

 

Exposures of the Greenmoor Rock

In very many places, the bedding planes of the very fine grained Greenmoor Rock are exposed along various paths, where abundant ripple marks can be clearly on their surfaces and, on some of the steeper paths, the individual beds are revealed to be very often no more than 10-20mm thick.

 

An exposure of very thinly bedded Greenmoor Rock

I carried on towards the viewing point and at the edge of the landfill site, which occupies a large former quarry and was just near to being completed, I found a path that descended down towards the Don Valley and from this I could see a section of interbedded thin sandstones and shales.

 

Alternating fine sandstone and mudstone in the Greenmoor Rock

Looking at the geological map, it can be seen that the strata here are strongly affected by the Don Monocline and it is only further to the north beyond Owlerton that they begin to resume the typical NW–SE strike, which is typical of the Coal Measures strata to the east of the Pennines.

 

Named sandstones to the east of the Don Valley

Continuing along the path towards Neepsend, the Greenmoor Rock is mainly argillaceous here and nearly all of it was used for brick making and at the old Neepsend Brickworks, the steeply dipping beds can just be seen at a distance.

 

A view of the strata exposed at Neepsend Brickworks

When using the zoom lens on my Canon Powershot G16, I could see that the strata here comprise alternating thin beds of sandstone, mudstone and shale, but the site is fenced off and I couldn’t see any way to get closer to it.

 

Strata exposed at the Neepsend Brickworks

Neepsend Brickworks is one of two geological Sites of Special Scientific Interest (SSSI) at Parkwood Springs and is considered to be the best available exposure of the Greenmoor Rock. It shows three coarsening upward cycles, with a wide variety of sedimentary structures and trace fossils that include that of the horseshoe crab Limulicubichnus.

 

Rocks encountered in the Neepsend Brickpit borehole

At the public consultation for the Parkwood Springs Draft Masterplan, held not that long after my visit, I mentioned to the Sheffield City Council officer on duty that the geology, which also includes Neepsend Railway Cutting SSSI, was very important. It seems that the geological interest hadn’t been properly considered and was duly noted – with the Friends of Parkwood Springs also being very interested in my observations, when I met them at a later Sheffield Heritage Fair.

 

A detail of the strata exposed at Neepsend Brickworks

Since being actively involved with geological conservation in South Yorkshire, I have seen several geological SSSIs become badly neglected, inaccessible or eradicated and it would therefore be very desirable to have this trend reversed.

A view of the Neepsend Brickworks from Solly Street