The Tatsi occurrence is located near Tatsi Creek about 65 kilometres west of the community of Smithers.
The showing area is underlain by maroon, red and purple massive bedded volcanics of the Lower Jurassic Hazelton Group (Telkwa Formation). Immediately to the northwest, a large stock of Jurassic Topley Intrusions cut the volcanic rocks. Dioritic dikes or sills intrude the volcanics in the area of the main showing, with sharp migmatitic contacts.
The Main zone of mineralization contains bornite, native silver, native gold, chalcopyrite, tetrahedrite, galena and trace pyrite in a relatively flat (15 degrees) easterly dipping bedding plane vein. The vein is up to 1 metre thick and is hosted by a bleached fine-grained tuff (with carbonate-filled fractures) on the footwall and coarse grained waterlain tuff to agglomerate in the hangingwall. The Main vein has been traced intermittently for about 100 metres. Channel samples taken by the operator yielded high-grade values (16.5 grams per tonne gold and 1158 grams per tone silver) (Property File - Visit Report by Tom Schroeter, July, 1995).
The Discovery zone is located in the west-central part of the claim, about 1 kilometre west of the Main zone. Galena, chalcopyrite, sphalerite, pyrite, specular hematite, malachite and azurite are hosted by intermediate to acidic pyroclastic volcanic rocks in close contact with a coarse grained hornblende granodiorite. It is represented by an intermittent alignment in a shear zone of quartz and quartz-carbonate veins and stringers, in areas of quartz and carbonate-altered rock. The zone has been traced over a strike length in excess of 200 metres and over widths up to 4 metres. Northward the exposures terminate in steep cliffs, and southward, the zone pinches out in diorite. A composite chip sample across a 2-metre section of the structure, comprised of quartz veins in bleached, ankeritic altered rock, assayed up to 9.19 grams per tonne gold. Silver from grab samples assayed up to 356.2 grams per tonne (Assessment Report 17971).
To the immediate east of the Discovery zone, a quartz vein stockwork system is exposed for 200 metres. Of seven grab samples, one sample assayed 0.37 gram per tonne gold and 12 grams per tonne silver associated with minor sphalerite and galena (Assessment Report 17971).
To the east, near the central part of the claims, two flat-lying quartz veins up to 40 centimetres wide are exposed. Values to 2365.6 grams per tonne silver and 0.885 gram per tonne gold are associated with chalcopyrite and a sulphosalt. For both the stockwork system and the flat-lying vein system, their extension to the north is not known (Assessment Report 17971).
In 1949, the property was originally staked but there is no record of any work. The property was re-staked in 1987 and an exploration program was completed. There are several areas of mineralization on the property. The Snowflake showing (093L 056) may also occur on the property.
In 1991, sampling was completed during a 1-day visit to the property. In 1995, with Explore B.C. Program support, Golden Hemlock Explorations Ltd. carried out a substantial program of geological and geophysical surveys, prospecting, trenching and 1820 metres of diamond drilling in 15 holes, mostly on the Main and Discovery zones. This work showed the Main zone mineralization is mostly part of a simple vein system which strikes easterly and dips 15-20 degrees to the south. The Discovery zone consists of several parallel veins and a 500 by 200 metre breccia zone believed to be of hydrothermal origin which may have potential for bulk mining (Explore B.C. Program 95/96 - M77).
