A long deep adit leads to a complex area communicating with blocked upper adits
| Year | Activity |
|---|---|
| 1845 | A 100m m level in cutting a 1m vein of pyrite, copper and zinc |
| c1870 | Sett purchased and promoted by Pen ‘Allt Silver-Lead Mining Co. Claimed 4 lodes including one assaying 100oz silver per ton of lead! |
| Jul 1870 | Extensive mill by river completed, including water wheel and crushers |
| 1871 | Winding petition and legal action against directors |
| c1872 | Great Mountain Silver-Lead Mine. A few tons of ore produced |
| 1874 | Deep Adit completed, ore at depth proving poor |
| 1878 | Promotion by Mining Corporation of Great Britain Ltd. |
| 1906 | Promotion by Benallt Copper & Lead Mines Ltd. |
| 1917 | Promotion by Consolidated Zinc & Lead Mines Ltd. |
| 1925 | Promotion by Nantlle Vale Mineral Leases Ltd. |
Summary from Bick.
The 600’ long deep adit reaches stope workings which can be climbed via two ladder shafts to an upper level whose adit is blocked by old fences. There is a second series of working extending up the hillside. The bottom adit is open, second blocked and third has deep shaft just inside entrance.
Publications (4)
- (1922); BGS - Mineral Resources of GB (c1920s) Vol XXIII - Lead & Zinc: Pre-Carboniferous Shropshire & North Wales; 111 pages
- (1991); CATMHS - Newsletter 031-November; 31 pages
- (2004); Ogofa GCPC Journal No 6,; 11 pages
- Bick, D.E. (2003); Old Copper Mines of Snowdonia, The; pp. 57-60
