A Recce at Ilkley Moor - Part 2

 

An information panel at the Lanshaw Lad boundary stone

After taking our lunch in Hangingstone Quarry, having discovered the location of the slickensides during our recce of Ilkley Moor for the Sheffield U3A Geology Group field trip, in August 2024, we went in search of Site 7 highlighted in Ilkley Moor - Its Geology and Heritage (IMIGH) by Gareth Martin and David Leather. 

 

A large glacial striation above Hangingstone Quarry

 

When studying A Level geography back in 1978, I was taught about glacial striations, caused by the scouring of bedrock by lumps of harder rock that were embedded in the base of the glacier that flowed over it but, to the best of my knowledge, I had never seen any of these in the Scottish Highlands or the Lake District, while studying geology at Nottingham University. 

 

Glacial striations above Hangingstone Quarry

 

Those on Ilkley Moor are described as “some of the finest examples of glacial striae” that can be seen in the UK with a west-east direction and their height of 150 m above the valley floor indicating the minimum thickness of the glacier. 

 

The Crocodile's Mouth

Finding one of the many paths that criss-cross Ilkley Moor, we stopped briefly to look at the geomorphological feature called the Crocodile’s Mouth and then carried on alongside Backstone Beck, which runs along a fault controlled valley. 

 

A view towards the waterfall on Backstone Beck

The beck flows through quite a deep valley with steep sides, which changes abruptly into a small channel upstream and is marked by a waterfall. This is interpreted as a knickpoint, which is eroding up slope and was possibly a response to the formation of a hanging valley during the glaciation of Lower Wharfedale in the Pleistocene Epoch. 

 

A view of the mass movement deposits beyond Backstone Beck

 

Looking south along Backstone Beck, the very undulating bracken covered landscape that is seen beyond the valley is due to the mass movement deposits, which are a common feature of the north facing slopes beneath the Addingham Edge Grit along Lower Wharfedale and was seen during the field trip to Otley Chevin. 

 

Mass movement deposits at Ilkley Moor

 

Continuing along the unmarked path to a viewpoint, where the very worn public footpath from the Cow and Calf Rocks fords Bakestone Beck, we briefly looked for the unusual coarse gritstone mentioned in the IMIGH geological trail; however, I didn’t see anything that stood out from the many examples of very coarse sandstone from the Millstone Grit Group, which I had seen on my travels in South Yorkshire, Derbyshire and West Yorkshire. 

 

A view down the path from Backstone Beck to the Cow and Calf Rocks

The next location on the geological trail was Rocky Valley, which marks the top of a rotational landslide, with Ilkley Crags forming its crown and the main scarp immediately beneath it. Having located the well used public footpath, we didn’t spend any time investigating its principal features, which can be seen from a distance, and set off to find the remaining 7 locations. 

 

Ilkley Crags and Rocky Valley

It very soon became obvious that the moorland here is again criss-crossed by a network of very poorly defined paths, which are marked on the 1:25,000 scale Ordnance Survey (OS) map but are not classed as public rights of way and signposted. 

 

The OS map covering the southern part of the geological trail

 

There are no obvious landmarks from which to get your bearings but, once we managed to find a path that crossed over Bakestone Beck, we kept close to the beck and carried on until we found the prehistoric Bakestone Beck enclosure and huts, which archaeological excavations suggest are late Neolithic (c.3000 BC) and late Bronze Age to early Iron Age respectively (800 to 500 BC). 

 

The Bakestone Beck enclosure and huts

 

Continuing along this path, we then encountered the Poetry Seat and Poetry Postbox, which forms part of the Stanza Stones Poetry Trail from Marsden to Ilkley, with poems by Simon Armitage cut into large stones by Pip Hall – the lettercarver whose work I had also seen on the Kilkenny limestone seats on The Moor in Sheffield.

 

The Poetry Seat and Poetry Postbox

Since leaving Rocky Valley we hadn’t seen any outcrops of bedrock, but a little further along the path I was interested to see a lump of very coarse gritstone sticking out of the path, which contained a bed of finger nail size quartz pebbles. Looking at the geological map, the underlying bedrock here is the Long Ridge Sandstone in the Millstone Grit Group. 

 

A detail of the pebbly gritstone in the path

So far on our recce, we had found most of the locations on the geological guide with relative ease, although the network of paths on Ilkley Moor is quite confusing and some of these would benefit from better descriptions of the precise locality and grid references. 

 

A Google Map view with Lanshaw Delves marked in red

 

Arriving at the Dales High Way, which is laid with flagstones, next on our list of places was Lanshaw Delves, is a west-east trending lateral moraine that is described as being approximately 600 m long by 40 m wide by about 3 m high. The Google Map satellite view and the OS map show that its western end is 115 m beyond the point where another public footpath splits off from it. 

 

The beginning of Lanshaw Delves on Google Street View

 

Keeping our eyes open for the junction of the two footpaths, we didn’t see any sign of this or any feature in the landscape that suggested that we had arrived at the beginning of a moraine and continuing along the Dales High Way and reaching the Lanshaw Lad boundary stone, we realised that we had completely missed this feature. 

 

The Lanshaw Lad boundary stone

Consulting our various maps, we thought that it would be easy enough to locate the path that would take us to the east end of Lanshaw Delves and carried on along a well established path past The Twelve Apostles stone circle. 

 

The Twelve Apostles stone circle

 

Failing to locate the public footpaths marked on the OS map, we had to stop three times to ask local walkers for help in finding a path that would enable us to get back to the Cow and Calf car park by the quickest route, without having to retrace our steps. All of the people we talked to told us that the paths on Ilkley Moor are notoriously difficult to navigate and, despite trying to follow their directions to the best of our ability, John and Trish had to use their GPS apps to get us to the Dales Way/Ebor Way. 

 

The OS map showing paths on our return from The Twelve Apostles

 

When we set off from Rocky Valley, the time was 13:34 pm and the route marked on the IMIGH geological trail covered a distance of 3.25 km. We had been confident that we would be back at the Cow and Calf car park well before 15:30 pm, which is the usual finishing time for field trips; however, although we didn't get completely lost, by the time we arrived at Hangingstone Road it was 16:23 pm. 

 

A distant view of the Cow and Calf Hotel

 

Finally arriving at the car park, we then finished what had turned out to be a very long and tiring day by enjoying a drink in the late afternoon sunshine at the Cow and Calf Hotel. Having collectively decided that we would have to revise our plans for the actual field trip two weeks later, we then set off on the long drive back to Treeton.

The Cow and Calf Hotel