A Geology Field Trip in Sheffield

Quarry Lane

In the month since I last went out with the Sheffield U3A Geology Group to Chrome Hill, I had travelled widely to Fishlake, Ashover, Mansfield, Barnby Dun, Barnburgh and Barwick-in-Elmet – encountering many interesting historic buildings and rock outcrops along the way.

A geological map of Sheffield

My next field trip was closer to home, and 15 of us met up at the Meadowhead branch of Morrisons supermarket on a cloudy morning in the middle of September. The purpose was to explore the variations of lithology in the Greenmoor Rock and to relate the rock outcrops, topography and geomorphology to the British Geological Survey maps.

The route of  the walk with the Sheffield U3A Geology Group

After handing out a general map of the route and looking at some maps of the meanders of the Mississippi River by Harold Fisk, we gathered at the gates to the delivery area at the rear of Morrisons, which occupies a large former quarry. 

A map of the Mississippi River by Harold Fisk

Unfortunately, despite making a formal request to gain access to this area, following a recce five months earlier, the Community Champion had not managed to act on this and we could only peer through the gates and study the rock exposure outside. 

An illustration of alluvial sedimentation

Another handout, as well as the Harold Fisk maps, helped the group to understand the vertical and lateral variation seen within the sandstone, mudstone and shale - the principal components of the Upper Carboniferous strata in Sheffield. 

In Graves Park

I had planned to spend some time at the quarry behind Morrisons, as it is the best accessible large exposure of the Greenmoor Rock in Sheffield, but instead took the group to the ponds in Graves Park, which occupy a steep side valley that cuts through the Grenoside Sandstone and underlying Greenmoor Rock. 

In Graves Park

Diverting briefly to look at some landforms that have been interpreted as lynchets, before walking down through Cobnar Wood to observe various exposures of sandstone and mudstone in the valley sides, before taking lunch at the playground at the bottom end of Graves Park. 

Observing mudstone in Cobnar Wood

After lunch, we continued with the first part of our route; however, after we had a good look at the large exposure of rock at the old brick yard, which is now occupied by Homebase/Dunelm, a few of the members who lived in this part of Sheffield left the group. 

At Heeley Retail Park

Nonetheless, the rest of us carried on down to the Heeley Retail Park, before crossing the River Sheaf - on the second part of the field trip - to look at the outcrop on Marden Road and then continuing up Brincliffe Edge to Quarry Lane, where we effectively ended our day.

An exposure of Greenmoor Rock at Quarry Lane