The Panasqueira tungsten deposit comprises a series of thin, flat-lying quartz-wolframite veins developed in the joints of a phyllite within the contact zone of a concealed granite intrusion. The largest concentration of veins occurs immediately over a granite-greisen high (cupola) on the No 2 Level of Panasqueira Deep. The horizontal extent of the veins, which pitch to the southeast, appears to decrease with depth. Individual veins average about 0.30m in thickness and can persist over hundreds of metres. Frequently, when one vein thins out, another forms close to it, with a small over- lap. There is considerable dilution during mining because the veins are so thin, which is why the mine goes to great lengths to not exceed the 2.2 m stope height.

The sub-parallel stacked quartz veins contain principally, wolframite, arsenopyrite, pyrite, chalcopyrite and cassiterite. The tungsten mineralised quartz veins have an average dip of 8°-10°SW. The mineralised zone has dimensions of approximately 2,500m in length and varies in width from 400m to 2,200m, continuing to 500m in depth. Previous mining was done in the upper levels and the existing reserves are from Level 0 and Level 4. The current reserves lie above Level 2 and Level 3 (90m below Level 2). The deposit, between Level 1 and Level 2 (60m vertical separation) consisted of seven or eight flat dipping veins with an average thickness of 0.3m (range 0.1-1.0m) that typically hosted the economic mineralisation over co ........

The mining method used at Panasqueira is a mechanized room and pillar method that has evolved during the past 50 years. The method is possible due to the sub-horizontal nature of the quartz veins and the very competent host rock.

The stoping process begins with ramps being driven to access the mineralized veins, in areas where diamond drilling has indicated quartz intersections equal to or above 18cm (indicated resources). When a vein is accessed, it is blocked out on a basic 100m by 100m pattern. Ore passes of 1.8 metre diameter raises are generally bored near drive/panel intersections, and allow ore to be dropped down to main haulage levels. Chutes are installed in the bottom of the orepasses to facilitate the loading of the wagons.

Equipment that is used for mine development and production includes electric hydraulic single boom jumbo drills, 3.5 cubic yard diesel LHDs, low profile 6 and 6.8 tonne LHDs and a raise borer. The target height of the stopes is nominally 2.1 m but increased to 2.3 m in areas where ore bearing veins are more variable in their dip, strike or thickness. The average height achieved is generally 2.2m. With an average in-situ mineralized zone thickness of 25cm, the applied planned dilution 880% i.e. 8 x times as much waste has to be mined within the 2.2m minimum height. No additional dilution factors are added.

As the veins are intersected with development, face sampling is used to verify mineralisation and indicate ho ........

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