The local Valtreixal stratigraphy in the Valtreixal area is dominated by 3 main formations, all of which broadly strike SW-NE, and dip at approximately 80o to the south- east.

a) Schists - Capas de los Montes. Very stratified and transformed by regional metamorphism, with intercalated quartzites, and marked at the base by conglomerates. Thickness approximately 1000m.

b) Quartzites - Peña Goda/Culebra. Alternating with a variety of types and colours of intercalated schists. Thickness approximately 50- 70m.

c) Slates – Pizarras de Luarca. Pelitic series of siliceous slates, phyllites and schists. This formation hosts most of the mineralisation at Valtreixal. High frequency of segregated quartz veins and schist bands sometimes rich in sulphur. Overall thickness approximately 300-600m.

Much of the mineralisation, especially scheelite, is situated away from the quartz veins and appears to be stratabound. Tin, in the form of cassiterite, occurs in and around the quartz veins. The Valtreixal linear mineralised zones appear, in a general sense, to be confined to specific stratigraphic intervals and there appears to be a degree of separation into tin and tungsten zones. Because of the stratabound nature of the mineralised zones within a shale basin some may consider a sedimentary, syngenitic origin for the tungsten mineralisation to be plausible.

The Valtreixal tungsten (scheelite) and tin (cassiterite) mineralisation exhibi ........

In the absence of geotechnical testwork, actual topographical toes and crest positions have been measured in areas where there are road cuttings or surface excavations for drilling platforms or access purposes. From these measurements, an average face slope angle of 56o was determined. Based on an assumed bench configuration of 10m benches, 4m berms every 2 benches, and 10m wide haul roads (or safety berms), this has given an estimated overall slope angle of approximately 42o. This overall slope angle has therefore been applied in optimisation work.

The majority of the pit design is cut into the west sloping existing hillside. A 10m wide haul road been put into the design with the exit point at the extreme west end, the lowest of point of the optimal pit rim, at an elevation of approximately 870m. This road is used to access lower parts of the design, down towards the lowest point at 820mRL. Access to the eastern, and higher, part of the pit will be gained from temporary access roads from the existing surface on higher benches.

Berms of 4m have been incorporated into the design every 20m vertically. For the extended highwall of the pit up to 1015mRL on the southern and eastern sides of the pit, additional 14m safety berms were put in every 60m vertically.

The overall pit is approximately 700m in length along strike, and 300m wide at its widest point.

Considerable amounts of earthworks have been completed over the past 2 years at Val ........

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