There are a couple of books on the silica mines around Glyneath, but I am not allowed to tell you about them. Here are a couple of mines that are any easy stroll:
No 2 MIDDLE SILICA MINE SN 9162 0795 This mine is located opposite the Upper Silica Mine and consists of three levels, the lower of which is flooded to various depths depending on the amount of rainfall. Access is gained by crossing the bridge between the two mines. The large entrance leads to walking size passage which descends down dip for 90m and then divides. To the right a steeply ascending passage leads to a short series of upper level passages running up dip.
To the left a small passage drops down into a large lower passage which runs parallel with the upper main passage, but at a lower level. After 30m a fall prevents the flooded section of mine from invading the first part of the lower series. The lower passage communicates with the upper series via a hole where water enters. This inlet is responsible for the flooding of part of the lower series. The last 23m of the lower series is quite deep as it ends in a sump. This has been dived, but ends after only a short distance in heavy silt. This is so close to the surface, that it could be yet another blocked entrance.
The large main passage continues to pass an inlet to the right, and this water flows across the floor to fall into the lower series. The inlet can be climbed fairly easily for 16m to a short upper series and yet another entrance high above the gorge. This passage is 50m long, and ends in a blockage which may have either been caused from material running in from the surface, or from a roof fall.
Finally the main passage runs up dip to emerge in another narrow entrance high about the Sychrhyd Gorge near Bwa Maen. Formally the mine contained a cluster of deep red stalactites which had been formed associated with organic matter. The straws were formed round the upper parts of slimy, pendulous fungi which is known to stimulate stalactites. The writer had seen these on a number of occasions but are now largely destroyed.
Reference:
Burgess, Peter M 1992 Bwa Maen quartzite mine workings. Cave and Quarry (1) Wealden Cave and Mine Society.
Cullingford, C H D 1964 British Caving RKP
Jones, Keith and Adams, Phil
MIDDLE SILICA MINE
Pontneddfechan, West Glamorgan
NGR SN 9160 0798
Surveyed by Isca Caving Club
BCRA 5d
February 1991
Drawn by Keith Jones
No 3 UPPER SILICA MINE SN 9164 0795 The most extensive mine in the area, and the most recent, is found on the north bank of the Sychrhyd 200m upstream of Bwa Maen, and has three entrances which face the river, and a further ten on the northern side. The triple entrance is to the left of the bridge, and is the mine most frequented by cavers. This is probably the most extensive mine in the area. The upper series is practically a veritable huge chamber where the `Pillar and Stall' method of mining is well illustrated. This large chamber leads towards several alternative entrances in the side of the hill. The large entrance chamber can be followed to the right down dip for a short distance to the flooded section. However, to the left the huge Pillar and Stall chamber leads up dip for some distance only to drop down dip again onto a passage which runs across the whole length of the mine. Above this passage various `entrances' lead to the huge chamber while below is flooded.
The flooded level consists of six levels varying in depth of up to -22m, according to the amount of rainfall, and between 80m and 250m in length. Each level has similar structure and appearance, consisting of square solid walls throughout. This mine is considered as an ideal site for underwater cave diving and photography.
Reference:
Jones, Keith and Adams, Phil
