The Sphal 4 area is underlain by Upper Paleozoic strata of the Stikine Assemblage. A 1989 grab sample of black banded siliceous volcanic rock with 10 per cent chalcopyrite assayed 1.18 per cent copper and 10.9 grams per tonne silver (Sample 30250, Assessment Report 19206).

Work In 1988, on the Sphal B property (Sphal 2, 4, 6 and 8 claims), by International Corona consisted of the collection 138 rock samples (Assessment Report 19206 (Appendix D, Prospecting Notes) (Map B)). No discussion report for 1988 work is available.

Follow up work in 1989 by Corona consisted of the collection of 61 rock samples. The 1989 field season report (Assessment Report 19206) contains some or all data from the 1988 field season. The Sphal A group of claims (Sphal 1,3,5,7) are reported on separately in Assessment Report 19197.