The Galore Creek region is underlain by Upper Triassic volcanics and sediments of the Stuhini Group. This area is flanked to the west by Juro-Cretaceous quartz diorite to granodiorite of the Coast Plutonic Complex. Middle Triassic sediments with Permian sedimentary and metamorphic rocks form the northern and eastern limit of the area with Permian limestone dominating. North trending faults define boundaries between Upper and Middle Triassic rocks and between Paleozoic and Triassic rocks. Strata is folded into a linked series of anticlines and synclines with west or northwest trending axes. Younger folds with north-northwest trending axes transect the earlier formed structure. Syenite (orthoclase porphyry) intrusions of Juro- Triassic Age disrupt the stratigraphy and structural trends. These intrusions form a series of dikes, sheets and two or more stocks. Several Eocene stocks composed of quartz monzonite are the youngest rocks in the region.
A two metre wide quartz vein carrying pyrite and galena occurs near the contact of folded and faulted tuffaceous volcanics and black phyllites with ankeritic sediments. Pyrite is common throughout the volcanics and prominent gossans are produced. Bright green malachite stained areas within the gossan zone occur occasionally. One 10 centimetre sample of the vein contained 49.4 grams per tonne silver, 0.21 per cent zinc, 0.29 gram per tonne gold, and greater than 1 per cent lead. A piece of malachite float, apparently from the above cliffs, contained 0.257 per cent copper.
Samples have yielded gold values up to 51.74 grams per tonne (Vancouver Stockwatch Jan. 18, 1989).
Alteration and mineralization are controlled by shears, faults and fractures that trend northwest and northeast, the highest intensity occurring where they cross. Copper and gold values vary; the most consistent and widespread values found to date occur within chlorite-epidote altered andesite volcanic rocks of the Blue and Cirqueback zones. A 1990 Blue zone chip sample of the zone assayed 0.177 per cent copper (Figure 4, Assessment Report 20674).
Work History
In 1987 and 1988 Consolidated Silver Standard Mines Ltd. conducted limited geological mapping, prospecting and geochemical sampling on the Jack claim. Silver Standard collected a total of 34 rock, 1 silt and 135 soil samples in these two years. Harrisburg-Dayton Resources Corp. carried out seven man-days of prospecting, mapping and rock and soil sampling of the Jack claim during 1989. They collected 320 rock and 315 soil samples. In 1990, Silver Standard collected 72 rock, 10 silt and 36 soil on the Jack, RB 6, 8 and 10 claims. Results of the above programs outlined several areas of anomalous gold-copper values associated with chalcopyrite-pyrite mineralization within strongly fractured, chlorite-epidote altered zones and quartz-sulphide veins. During the 1987 to 1990 period, the Blue and Cirqueback zones were discovered and explored.