The Nidd Gorge

The geology around Knaresborough

Compared to 2016, when I got on the bus and train to travel as far as I could from Treeton – to survey a wide variety of mediaeval churches and associated historic buildings – 2017 was a comparatively quiet year.

Knaresborough railway station

I had explored parts of the Sheffield Round Walk and the villages of Norton and Grenoside, as well as having a close look at the Mam Tor landslip, but I spent most of the time much nearer to home – helping out with the maintenance of St. Helen’s church and trying to get another Glowing Edges Designs project off the ground.

A view of the railway viaduct in the Nidd Gorge

It had taken 15 years for an idea for a display at Clifton Park Museum to turn into the production of a set of unique Crepe de Chine silk scarves and I was in need of a break – which was provided by the offer from an old friend to spend the weekend in Knaresborough.

A view along the Nidd Gorge from the A59 road bridge

Arriving on the train across the viaduct from Leeds, I didn’t really notice the Nidd Gorge which, along with Knaresborough Castle and Mother Shipton’s Cave, is one of Knaresborough’s principal tourist attractions; however, with the plans to spend an afternoon in Harrogate cancelled, I was shown around this very attractive place. 

A cliff on Waterside

Walking down Waterside to the river from the road bridge on the A59, I didn’t stop to investigate further as I would have done if I were not in company and, even when passing under the railway viaduct, I didn’t take much notice of the surrounding gorge – until I encountered the vertical cliff face upon which the castle is set.

Magnesian Limestone above the Addlethorpe Grit

Knowing the Magnesian Limestone very well - based on geological surveys in South and West Yorkshire, I immediately recognised the pale limestone of the Cadeby Formation high up in the cliffs. Beneath this, I assumed that the red/orange cross bedded sandstone was a thick deposit of the Yellow Sands Formation - which I had seen before in Hooton Pagnell and Pontefract.

Sandstone in the Nidd Gorge

I have since discovered that this is actually the Addlethorpe Grit from the Millstone Grit Series which, like many Carboniferous sandstones that are found immediately below the Carboniferous – Permian unconformity, had their iron bearing minerals oxidised in the arid Permian environment. 

The Addlethorpe Grit

Examining the photographs that I took at the time, the distinct reddening of this sandstone provides a good example of the weathering of uplifted Carboniferous rocks in the hot and arid Permian climate – and the rocks that form the lowest part of the cliff here seem to be different again, with a massive nature that is characteristic of the Millstone Grit. 

The Chapel of Our Lady of the Crag

Walking further south-east along the Nidd Gorge, a plaque told us that we were near to the Chapel of Our Lady on the Crag – which deserves further investigation - and we carried on looking at the geology, architecture and sculpture until we decided that we had walked far enough for the afternoon and that is was time to get back to Knaresborough to have a well earned drink. 

An example of vernacular architecture along Waterside

In the hour and half spent wandering along the east side of the Nidd Gorge, some interesting and varied geology had been encountered and, using a guide produced by the British Geological Survey, this would make a particularly good field trip for the Sheffield U3A Geology Group - especially if combined with a visit to Knaresborough Castle and a wander around the very attractive market town.

A cliff formed on the west side of the Nidd Gorge