Recce No. 2 in Cressbrook Dale

 

A view of Peter's Stone on the path from Wardlow Mires to Mires Lane

Arriving in Cressbrook Dale, after having a good look at the geology and extensive remains of the lead mining industry in Tansley Dale, which is a Scheduled Monument, Stuart and I continued with our recce for the Sheffield U3A Geology Group June 2024 field trip. 

 

A view of Cressbrook Dale from the bottom of Tansley Dale

 

On the recce that I had undertaken with the group leader Paul in February, we had parked at Wardlow Mires and had only managed to explore the south side of Cressbrook Dale up to just beyond Peter’s Stone, where we found the Cressbrook Dale Lava along the footpath, before we aborted the day due to the flooding of the valley and a prior injury to Paul’s foot.

 

The stream crossing

 

Crossing the stream and passing the area of disturbed ground on the east side of the valley, which is also associated with lead mining, we continued north along the public footpath and stopped to look at the streambed, which is usually dry from this point to Wardlow Mires. 

 

A view of the dry streambed

 

The rocks, moss and other vegetation along the length of the streambed were lightly covered with a deposit of calcium carbonate, which reflects its nature as a winterbourne - as I had seen in February after an expended period of heavy rain. 

 

A dry valley cut by a tributary

 

Continuing northwards, we stopped to look at the dry tributary valley to Cressbrook Dale, where very subtle changes in the slope and the vegetation show areas where there has been soil creep down the valley. While looking at this, we were treated with a view of boxing hares on the hillside, but they were well out of reach of the zoom lens on my camera. 

 

An outcrop of the MDLF with Lithostrotion corals

 

Reaching the outcrop of Cressbrook Dale Lava in the path, where I found more outcrops that I had not noticed on the previous recce, we made our way up to Peter’s Stone, an example of a translational landslide, where I showed Stuart the examples of Lithostrotion corals in the Monsal Dale Limestone Formation (MDLF) that I had previously found and took in the panoramic view along the valley towards Wardlow Mires. 

 

A panoramic view of the north end of Cressbrook Dale

Following the path down to the valley, we encountered another part of the now dry streambed where the tufa like deposits were more like the encrustations that are developed in an extreme form in petrifying springs like the one at Matlock Bath. 

 

Tufa like encrustations in the streambed

 

We then looked for an opening in the dry stone wall that runs along the valley floor, with the intention of exploring the outcrops of the MDLF that are easily accessible on the north side of the valley. When visiting Cressbrook Dale back in 1995, as part of my assessment of the geotourism value of the Regional Important Geological Sites in the Peak District National Park, I found some spectacular silicified Lithostrotion coral and large blocks of cemented scree. 

 

Looking for Lithostrotion corals

 

From memory, I recall that I had seen these at quite a low level, where the dip of the MDLF is such that there are plenty of exposures not far from the valley bottom. We had a good look but were unable to find any corals or blocks of scree, but we did find a bed that was packed with brachiopod shells that Stuart described to me as a "death bed". 

 

The discovery of a "death bed"

 

Crossing back over the stream to the south side of Cressbrook Dale, we investigated a differentially weathered bed that looks very much like one that we had seen on the High Peak Trail a couple of years earlier, which proved to be a clay wayboard, but we found no evidence of weathered volcanic ash and carried on to Wardlow Mires. 

 

A view of Peter's Stone on the path from Wardlow Mires to Mires Lane

 

We walked for a short distance along the very busy A623 road, where there is no path, until we reached a public footpath that would take us across the fields and bring us on to Mires Lane. From here we had good views of Cressbrook Dale in both directions and particularly of Peter’s Stone from a completely different perspective.

 

A view down Cressbrook Dale

 
Arriving at Mires Lane, we were surprised to be stopped by a young African woman who asked to have her picture taken using her mobile phone, with Peter’s Stone in the background, before pausing at a layby to get views along the valley to Wardlow Mires and of the outline of the Cressbrook Dale Lava and Litton Tuff to the south and then heading back to Litton. 

 

A view up Cressbrook Dale from a layby on Mires Lane

A Geological Recce of Tansley Dale

A view up Tansley Dale

 

On a warm and sunny last day of April 2024, having not been out since my circular walk that included All Saints churchyard, an exploration of the building stones of Bents Green, a walk to Whirlow and then back to Ecclesall, I set out with my friend Stuart, who had co-led a field trip with me to the High Peak Trail a couple of years earlier, to undertake a recce for the June 2024 Sheffield U3A Geology Group field trip. 

 

The circular route from Litton via Tansley Dale and Cressbrook Dale

 

I had previously undertaken a recce in February, which was cut short due to the fact that the valley was flooded after a period of exceptionally wet weather and that the group leader Paul, who I went with, had sustained an injury a few days before that turned out to be a broken toe. 

 

The first stile on the path from Litton to Tansley Dale

 

Arriving in Litton and checking the availability of parking, our first task was to assess the accessibility of the first two stiles on the route. Before the recce, I had contacted a Peak District walking group to ask if the water levels in Cressbrook Dale had subsided and someone had responded to tell me that she had found these quite difficult to negotiate without assistance. 

 

The second stile on the path from Litton

Most of the group members are in their 70’s and, although they need to have a decent degree of mobility and fitness to cope with the terrain that is typically encountered on a field trip, the U3A have increasingly emphasised that field trip leaders must undertake formal risk assessments and more - just one of the factors that has certainly led to my diminishing interest in this organisation.

 

The public footpath from Litton to Tansley Dale

Having agreed that these stiles wouldn’t present a problem for our members, we continued for a few hundred metres until we reached the head of Tansley Dale. I had never heard of this dale before but, when undertaking preliminary research, I discovered that it is a Scheduled Monument with descriptions of the former lead mining industry here being provided by Historic England and the Derbyshire Historic Environment Record. 

 

The approach to Tansley Dale

 

When the upper part of Tansley Dale came into view, I could clearly see the disturbed ground but Stuart, who had written his dissertation on lead mining in the Peak District as part of his joint honours geology and geography degree, was able to point out many more features.

 

A view down Tansley Dale

 

Continuing down Tansley Dale past the foundations of walls and waste rock that have largely become overgrown, on either side of the valley there are several entrances to adits which coincide with the position of the lead rakes on both sides. 

 

An entrance to an adit

The 1:50,000 British Geological Survey map shows that a series of rakes run west to east over from the head of Tansley Dale, which continue for a distance of nearly 5 km and workings on these are clearly visible on LIDAR maps. 

 

The geological map showing the lead rakes in and near Tansley Dale

 

Alongside the path, there are several small outcrops of the light facies of the Monsal Dale Limestone Formation (MDLF), which are shallow shelf deposits that very often contain brachiopods and corals. We did not notice any fossils, but there was an opportunity to take a measurement of the strike and dip on the exposed bedding planes, which Stuart compared to the measurements that are recorded on the maps that he had brought with him. 

 

Measuring the strike and dip

 

Immediately above the first adit that we encountered, a thick layer stands out as having a very rough and irregular texture that contrasts with the limestone above and below it. Getting close enough to touch it, the photo that I took shows what look like shrinkage structures that are orientated at right angles to the outcrop. 

Calcite crystals

We didn’t reach any conclusion about what we were looking at but, enlarging one of my photos, I can see rhombohedral cleavage, which is typical of the mineral calcite and suggests that this is part of the mineral vein that the lead miners were exploiting.

 

Examining calcite in a mineral vein

 

Continuing down the path past small areas of waste rock that are composed of lumps of the unfossiliferous dark facies of the MDLF, which was formed offshore in much deeper water, our next stop was an incongruous relatively level feature that was not natural and Stuart immediately recognised this as the main waste tip. 

 

A view down Tansley Dale while standing on the edge of a waste tip

 

My botanical knowledge is not great, but I know just enough to able to recognise wild orchids when I see them and, as I later discovered from the information panel at Tideswell Dale car park, the early purple variety were flourishing on the ground that had been undisturbed by lead mining. 

 

An early purple orchid

 

Making our way down to the end of Tansley Dale and looking back up the valley, another adit can be seen high up the hillside on its north side, with the position of the rake being marked by a linear feature of excavated ground above and below it.

 

A lead rake at the east end of Tansley Dale