Case Studies - Mineral Exploration

GEOTEM Survey in Copper Lake, Sweden

Brandon Gold Corporation (BG.V) completed a major diamond-drilling program on its 100% owned Kiruna property block in northern Sweden in 1998. The Kiruna district is one of the great mining districts in the world. The largest mines in the area have been for iron. However, copper production has also been very significant.

Survey Data Discovery Line Profile

The Viscaria Mine produced 12.54 million tonnes of ore from an in-situ mineable tonnage of 14.25 million tonnes grading 3.54% Cu, 0.70% Zn and 0.30 g/t Au. Only the copper was recovered. The Pahtohavare Mine produced 1.68 million tonnes with a recovered grade of 1.89% Cu and 0.88 g/t Au. The target of Brandon Gold's drilling was the regionally developed sulfide exhalite zone in the mine stratigraphy, or "Viscaria formation", within which these two mines occur. Coincident positive magnetic anomaly Distinct anomalous EM response on both Z-Axis and X-Axis Data Till geochemistry was combined with a GEOTEM survey to generate drill targets. Areas were selected along the favourable Viscaria formation on the basis of coincident anomalous till geochemistry, electromagnetics, and magnetics, plus proximity to the Viscaria mine. Areas were then followed up by Max-Min and magnetics.

A large number of targets were generated. An initial eight, some internally multiple, were followed up with a drilling program totalling 4,948 metres in 32 holes. The drilling program itself indicated additional target potential.

A fence of 5 holes was drilled, at the discovery, through an intense, proximal exhalative system from the stratigraphic top down. The Viscaria formation varies in thickness up to 500 metres. Exhalite facies varied, from an oxide rich top (locally hematite, but mostly banded magnetite iron formation), through laminated massive to semi-massive and disseminated pyrite, with accompanying carbonates and cherts to a basal silica sinter. The host is, predominantly, intensely altered felsic tuff. The geophysical signature of this mineralisation was extremely strong and very complex.

Copper mineralisation as veinlets, disseminations and laminae of chalcopyrite were noted in all holes in the fence. One hole intersected 4.15 metres grading 0.70% Cu and 0.04% Co, including 1.65 meters grading 1.45% Cu and 0.06% Co. Another hole yielded interesting anomalous copper mineralisation throughout its entire length (241.6 meters). The higher grade portion of the hole contained 15.75 meters grading 0.75% Cu and 0.03% Co, including a 9.10 metre intersection grading 0.88% Cu and 0.05% Co. This discovery has been dubbed "Copper Lake" and was the subject of a press release dated June 10, 1998. The Copper Lake discovery is approximately 35 kilometres north-northeast of the Viscaria Mine.

Geological section Copper Lake

Five hole drill fence Cu Mineralisation as Chalcopyrite Interpretation of the ground geophysics at Copper Lake, assisted by the drilling, indicates that the known zones of significant mineralisation are distinct and can be followed for at least 500 metres along strike. However, the airborne data indicate that the zone of greatest interest may continue much further. Moreover, what is currently thought to be the most intense portion of the anomaly was transected on its flank by the drill fence. A follow-up program is being planned.