Nent Valley- Reading a Pennine Landscape.

N.E.G.S. and Nat. Hist. Soc. Field visit to Alston - Nenthead. Leader: Brian Young. Oct. 2nd. 2010

(Any errors are entirely the fault of the web editor)

           Fourteen members of N.E.G.S. and the N.H.S. (Nat. Hist. Soc.) turned up at Nenthead Mining Centre on a fine sunny day - unusual for this area. From here, through car sharing, they were transported to Alston. The purpose of the trip was to walk back to Nenthead looking at Lower Carboniferous geology and industrial archaeology of the North Pennine Orefield. Our leader gave a comprehensive outline of the geology and industrial archaeology of the area. Other sources of information can be accessed on the N.E.G.S. website at http://northeast geolsoc.50megs.com/pages/page12carboniferous.htm. and also at http://nora.nerc.ac.uk/7886/1/OR07032.pdf
         
         The traverse to Nenthead began just northeast of Alston by the River Nent at NY720467, about ½ mile from its confluence with the River South Tyne to the west. The leader explained how an exploratory and drainage level for minerals, mainly galena (lead sulphide) was driven from here for about 6 miles to Nenthead. The starting point was also on the same horizon as the Scar Limestone. Geologically, the traverse extended from the Scar Limestone, through the Great Limestone, to the Little Limestone.

The party then moved on to Gossip Gate Bridge and Waterfall formed by the more resistant Five Yard Limestone. The next stop was on a grassy floodplain which during the spring is populated by plants, e.g. spring sandwort, scurvy grass and thrift, tolerant to metals such as zinc and copper sulphides and cadmium borne in solution by the river. As a result the river itself is faunally poor. The leader emphasised that human activity was not to be blamed; the river would pick up metals in solution when passing over ore bearing veins.

After having had lunch at a waterfall (NY7332 4702) caused by a resistant sandstone overlying the Five Yard Limestone  the party moved on and ascended up to the site of Blagill Mine (NY7403 4728) famous for being a source of baryto calcite (barium calcium carbonate) and hence a Site of Special Scientific Interest (SSSI). It is thought that the derivation of the word Blagill comes from the German for lead which is Blei; Miners of German nationality once worked here.

On reaching the top of the Great Limestone panoramic views showed the typical bench/slope sequence of the Yoredale facies, the benches consisting of the more resistant limestones and sandstones.

Further on, not far from Nenthead village the party examined the entrance to Brownley Hill Mine at NY7755 4472. It is well known for being the type locality for the mineral Alstonite.

On reaching Nenthead the leader pointed out that although the area was no longer worked for minerals such as galena and zinc sulphide, the day might come when extraction might once again be economically viable, but this would in no way spoil this Area of Outstanding Natural Beauty (AONB) if carefully planned.

After the leader was given a vote of thanks for such an interesting and informative day the party dispersed to their transport. 

Click here for photo's from the field trip.