Field Trip Report Mine and the th Sunday 12 May 2013

Snailbeach Mine

Our field trip to the area of our region began with a morning visit to the Snailbeach Lead Mine near . Worked from Roman times up until 1955, it was once Shropshire’s biggest metal mine. It is purported to have the best set of lead mine buildings in the country. The site is managed jointly by and the Shropshire Mines Trust.

We were met at the village hall car park by our guide, Peter Sheldrake, before walking up the hill towards the tiny hamlet where the main mine is situated. We began our tour in the Locomotive shed which used to house several steam locomotives. These ran on the narrow gauge Snailbeach District Railway from the main line at , taking lead ore to customers and bringing back coal for the boilers. Here, Peter took the opportunity to explain the history of the mine and geology of the local area.

Although the miners mainly extracted lead ore (), smaller quantities of Barite, Calcite, Fluorspar, and Zinc were also obtained. The main rock in which the minerals were deposited is the Mytton Flags, which consist of fine silts and grits deposited onto the beds of ancient estuaries during the early Ordovician, approximately 450 million years ago. These sediments now attain a present day thickness of over 650m and make up most of the rock types that lie at the base of the Stiperstones range of hills. These sediments were then subject to major earth movements causing them to fold and fault and leaving those at Snailbeach tilting almost at 70°. During the Devonian, deep seated igneous activity resulted in hydrothermal fluids ascending via these faults, forming near vertical mineral veins.

We then walked to the main area of buildings, which included the Mine Office which once housed a small assay laboratory, the Blacksmiths shop where all the tools for the mine were once forged and the Pumping Engine House which dated back to 1790. In front of the Pumping Engine House was the capped George’s Shaft, some 750ft deep (all the depths were measured in yards so the bottom of the shaft was at the 250 Yard Level).

George’s Shaft; the original shaft for the It was in this shaft in 1895 that the mine had its mine with its wooden headgear rebuilt in worst accident. 7 men died when the winding 1999. rope taking them down broke and the cage crashed to the bottom.

Across from the shaft is the Engine House Next, the miners dry (now the visitor’s where a horizontal steam winder was centre) which was once used by the miners installed in 1872. to dry their work clothes and a dormitory for men who lived outside the area.

We then passed the Day Level entrance which Finally, we looked at the Compressor House

was driven in 1848 to intersect the Engine built in 1881, which contained the machinery

Shaft we were to see further up the hill. that supplied the compressed air for the rock

drills and ventilation. At the far side was the

Boiler House and Chimney.

We then made a steep assent of the hill behind the In the front was the grilled Engine Shaft which mine to the Pumping Engine House. Its construction was the main shaft of the mine and was 1,300ft is very similar to those you see all over Cornwall. deep and connected with the Day Level Installed in 1858, it held a 60"engine that worked 6" mentioned above. diameter pump rods in the shaft. Pumping ceased in 1911 causing the mine to flood.

We then left the main mine complex and walked up the valley passing the Candle House, where tallow candles were produced and sold to the miners, and the double walled Explosives Magazine, where the two walls allowed one-way traffic of miners going in to collect explosives and fuses.

This then brought us to the entrance to the Perkins Level where we all donned our hard hats and got our torches at the ready. The mine is unlit which gave us a good idea of the conditions the miners worked under with only their tallow candles for light. We also had to contend with 4-6 inches of water on the floor so our wellingtons were an essential piece of equipment.

We entered the mine and walked for some way before taking a right turn into another gallery. This led us to a stope in which we could see a large barite vein and remains of galena in the walls. We retraced out steps before taking another gallery which took us over a small bridge over the top of another stope.

In the mine Peter explained the various techniques used by the miners to extract the lead and barite.

We ended our tour back at the visitor’s centre where we had time to look at the displays and watch a DVD about the mine and its history.

This had been a very interesting morning, not only did we learn about the geology of the area, but we were also given a brief insight into the lives of the men who lived and worked at the mine.

Stiperstones

After lunch, with fingers crossed that the forecasted rain would stay away, we embarked on a group self guided visit to the Stiperstones National Nature Reserve. Situated just three miles south of Snailbeach, this is a well know landmark in the Shropshire Hills, with its stunning landscape and dramatic scenery.

We drove to the car park before putting on walking boots and heading uphill towards some very interesting looking rock outcrops silhouetted against the skyline. These were the tors of the Stiperstones quartzite’s.

The quartzite’s are exposed as tors along the ridge with names such as The Devils Chair, Cranberry Rock and Manstone Rock. They show steeply dipping beds mostly at an angle of 70°, which Karen kindly confirmed with her Clinometer.

This cross-section, courtesy of the Shropshire Geological Society website, shows the Stiperstones quartzite at the base of the sequence. Folding upwards it makes a ridge, running in a NNE/SSW, for some 6 miles. The quartzite rests unconformably on Cambrian (Tremadoc Series) shales and is overlaid by the Mytton and Tankerville Flags (seen this morning at Snailbeach), a bluish grey shale. These three make up the first part of the Ordovician shelf sequence know as the Arenig Epoch.

The quartzite’s are thought to have been deposited in shallow water in a possible beach environment. They are a hard, white or grey siliceous sandstone (not a true metamorphic quartzite), with a higher percentage of quartz than the similar, but older, Cambrian Wrekin quartzite seen at the Ercall quarry. Within it, there are occasional bands of conglomerate with small rounded quartz pebbles, further indicating an ancient beach deposit.

We walked along the ridge to the Devils Chair, taking a few detours to climb the rocks and, with the rain staying off, we then headed back to the cars (dry if a little wind swept!). This was an interesting end to a good day’s geology, as well as providing great views towards the Welsh mountains and the Long Mynd.