An Exploration of the Rivelin Valley

 

Chatsworth Grit in the Rivelin Valley

Arriving at the end of the path alongside Wyming Brook, my plan was to follow Wyming Brook Drive to the west entrance to the nature reserve on the main A57 road, from where I would catch the No. 257 bus back to Sheffield.

 

A stream cutting into the head

Having walked for a kilometre, with only a small stream cutting into the head providing any geological interest, I arrived at a U-bend in the track, where a stone bridge crosses a small tributary of the Rivelin Brook and went to investigate the various rocks in the streambed.

 

A tributary of the Rivelin Brook

Looking at the British Geological Survey map, the rocks at this point are assigned to the Marsden Formation, which is found immediately below the Chatsworth Grit and is composed of sandstone and mudstone/siltstone, which are distinguished on the map but not named.

 

A geological map showing locations of samples

Many of the rocks that I could see were small rounded boulders that I presumed to be Chatsworth Grit, as I had seen along the length of Wyming Brook, but I obtained a sample of well bedded and relatively angular sandstone with my Estwing hammer.

 

A specimen from the Marsden Formation

Looking at the specimen with the naked eye, it is light brown in colour and contains distinct laminations, with an abundance of mica along the bedding planes, with the weathered surface developing a blackened appearance and an orange rim penetrating the fresh body of the sandstone. Viewed through a hand lens, it is very fine grained and contains specks of a dark mineral that is generally converted into orange iron oxides/hydroxides.

 

An outcrop of Chatsworth Grit

 

Continuing along the track, which follows the outcrop of Chatsworth Grit, an extensive and easily accessible exposure provided an opportunity to obtain a sample that was less weathered than those that I had collected at Wyming Brook.

 

An outcrop of Chatsworth Grit

Again, this proved very difficult and the two small specimens that I collected were both weathered to a certain degree and I could break them with my fingers. The larger piece is coarse grained and slightly pink in colour, with grains of white weathered feldspar and flecks of oxidised iron bearing minerals and the smaller one is very iron stained.

 

A specimen from the Chatsworth Grit

Crossing over the Rivelin Brook, which flows down from the moors into the Rivelin Dams, the bridge is constructed of squared and rock-faced blocks of Chatsworth Grit, with the large coping stones being quite crudely shaped and tooled.

 

The bridge over the Rivelin Brook

With the Chatsworth Grit being very suited to use for civil engineering purposes, quarries in the immediate vicinity would have been opened specifically for the construction of the dams and associated structures and some of these are visible to the immediate west of Rivelin Rocks.

 

The location of old quarries above the Rivelin Dams

I arrived at the bus stop, having walked only 5 kilometres and with at least 25 minutes to wait before the hourly No. 257 bus arrived, so I just decided to walk back towards Sheffield to make the most of a warm sunny day.

 

The spillway at the Rivelin Dams

 

Stopping only to look at the spillway at the Rivelin Dams, I progressed at a good speed and checked the time at each bus stop, which seemed to be approximately every 500 metres. I calculated that I would have more than enough time to get to my final stop, only to discover that the distance I had to walk was 1500 metres and the bus overtook me, running 5 minutes early, when the bus stop was in sight.

 

A view along the A57

Cursing my bad luck, I continued until I found a shady spot and stopped for ten minutes to finish my packed lunch and have a drink before starting off again up the hill, where I was very surprised to see some crozzle used to top the boundary walls.

 

A boundary wall topped with crozzle

With the midday sun beating down and the incline up the A57 starting to take its toll on my legs after a good walk, I finally arrived at the Valleyside Garden Centre, which I later discovered is sited in the old Bell Hagg Quarry – but I had done enough exploring for one day and I was just glad to sit down on the grass.

My exploration of Wyming Brook and the Rivelin Valley