The Sphal 1 showing area is underlain by volcanic rock of the Upper Triassic Stuhini group and Upper Paleozoic strata of the Stikine Assemblage.

The dominant geologic feature of the Sphal 1 is a strong north-south trending fault with abundant quartz and ankerite which separates Triassic volcanics from a Paleozoic sedimentary sequence. Triassic rocks are generally andesitic tuffs which are widely propylitized along the fault trace. Sediments include a buff coloured dolomite with black graphitic argillite beds and lesser quartzite lenses. Splays off the main structure contain ankerite and quartz but only trace amounts of sulphide. Samples taken in 1988 assayed up to 0.11 per cent copper and 1.1 grams per tonne silver (sample 1305, Assessment Report 19197).

Some work was done in 1988 by International Corona but no report is referenced for this. Follow up work in 1989 consisted of the collection of 45 rock samples. The 1989 report (Assessment Report 19197) contains some or all data from 1988 as well as the 1989 field season).