New Glencrieff Mine (Wanlockhead Mine; East and West branch of New Glencrieff Vein), Wanlockhead, Dumfries and Galloway, Scotland, UKi

Regional Level Types
New Glencrieff Mine (Wanlockhead Mine; East and West branch of New Glencrieff Vein)	Mine (Abandoned)
Wanlockhead	Village
Dumfries and Galloway	Council Area
Scotland	Country
UK	Country

The mine shaft and works are situated just below the village of Wanlockhead and at an elevation of 1195 feet. The shaft is sunk on the west branch, or West Grove Vein. It has been continued downwards for a distance of 240 fms. on the slope of the vein, and is connected with the main or New Glencrieff Vein by levels and cross-cuts. The New Glencrieff Vein appears to have been discovered between 1710 and 1721, and soon afterwards a fair quantity of ore was raised from it, but not sufficient to pay expenses. During the driving of the Glenglass adit-level about 1740, the west branch of the vein was discovered. It proved to be very rich and a large quantity of ore was raised. The mine was worked extensively till about 1770 when it was abandoned as unprofitable. It remained in this condition for over seventy years, but was opened up again by Mr. J. Stewart between 1842 and 1850, and the shoot of ore cut at the south end of the New Glencrieff Vein has proved one of the richest in Scotland, and is still being wrought.

Description of the Workings.-- The mine has now been sunk to a depth of 1320 feet, and the bottom of the shaft is about 140 ft. below sea-level. The extent of the workings and the general disposition of the shoots of ore can be seen from the plan and section shown on (Figure 2) and (Figure 3). The water is pumped in two stages, from the bottom to the 160-fm. level, and from there to adit-level, which crosses the shaft at about 90 ft. from the surface.

The main vein itself varies greatly in thickness. It is usually strong, cavernous, and well-defined, but owing to slight changes in direction, and to its being shifted laterally by small strike faults, it is often rather difficult to follow. At the south end the top levels were exceedingly rich in galenaPbS, and the main shoot of ore was practically continuous for 200 fms. At the 80-fm. level a large quantity of hemimorphiteZn₄Si₂O₇(OH)₂ · H₂O was also encountered, and at the 120-fm. level this gave place to blendeZnS. From that level downwards the galena gradually gave out until at the 200-fm. level the vein consisted almost entirely of blende. A peculiar fact in connection with the blende is that it is restricted to the south end of the vein, and ends abruptly to the north, though quite recently specimens of blende have been obtained in the 240-fm. level at the north-west end of New Glencrieff Vein. A small quantity of blende was also met with in some of the upper levels in the " West Branch." Southwards from this main shoot of ore the vein becomes unproductive, and although the 120-fm. level was continued a distance of half-a-mile in a strong open vein no ore was touched in the course of the work. Recent developments at the north end of the 160-fm. level have been more successful, although a considerable amount of trouble was encountered owing to the drivage deviating from the course of the vein (Figure 2). Eventually by crosscutting 21 fms. to the east the vein was picked up again in its true course, and was found to be ore-bearing. The level was then continued a considerable distance through unproductive black shales, but eventually a shoot of ore was cut, which is 50 fms. in length and valued at 12 tons to the fathom. The 240-fm. level has also been driven southward, and the shoot of ore which exists in the 200-fm. level has been found to continue down to the lower one.

The sulphide ores are galena, jamesonite, zinc-blende and pyritesFeS₂, and of these galena and blende are worked. The oxidised ores are pyromorphitePb₅(PO₄)₃Cl, cerussitePbCO₃ and hemimorphite, and the gangue minerals are calciteCaCO₃, dolomiteCaMg(CO₃)₂, quartzSiO₂, barytesBaSO₄ and a little witheriteBaCO₃.

The Treatment of the Ores.-- The mine is worked by overhand and underhand stoping, and a good deal of the material is handpicked underground. After lifting, the material is screened, and the oversize portion shovelled on to a conveyer along which a number of men are posted to pick out the barren material. From here it passes to a stone-breaker and then to a hopper, which also receives the smalls from the screens. From here the material is first fed into the crusher rolls and then on to the trommels and jigs. The slimes pass on to the classifiers, and the various types of sand and slime tables employed. The plant is also equipped with a small chat mill to deal with the middlings thrown off from the 10-mm. jigs. The tailings from the jigs are clean, but those from the slime plant generally contain a little ore. The lead concentrates yield about 81.5 per cent. of lead, and the dressed blende is sold as containing 50½ to 52 per cent. of zinc.

The galena is smelted at a plant which is situated about one mile further down the valley, and consists of two roasting furnaces, five Scotch hearths, and one slag hearth. Both silver and fume lead are produced, but the desilverising "Pattison" process has been abandoned since 1910.