The Sutl occurrence is located about 3.6km south of King Salmon Lake.
The Sutl area is underlain by sedimentary rocks of the Lower Jurassic Takwahoni Formation (Laberge Group). High-level quartz-phyric, felsitic intrusive rocks of the Paleocene to Eocene Sloko Hyder Plutonic Suite intrude the Laberge strata.
A zone of silicified vein breccia was discovered in 2004 by Rimfire Minerals Corporation. This zone covers an approximate area of 400 by 50 metres of patchy silicified sedimentary rock. Silicified zones are hosted in clastic sedimentary rocks and are spatially associated with quartz feldspar biotite porphyritic dikes. Outwards of the core silicified area, silicified vein breccia occurs in narrow fault zones trending 110 degrees. Porphyritic dikes trend 340 degrees, dip steeply and range from 3 to 15 metres wide; it is unclear if the dikes serve as brittle conduits for mineralizing fluids to pass or if they supply the fluids hydrothermally altering/mineralizing the host rocks.
Silicified vein breccia is dominantly composed of brecciated sandstone and conglomerate with chalcedonic quartz pyrite galena sphalerite and trace sulphosalt and chalcopyrite filling the matrix of the breccia. Several samples from this zone returned assays between 0.8 and 4 grams per tonne gold, while one returned 13.35 grams per tonne gold and another 1255 grams per tonne silver (Assessment Report 27589). The distribution of precious metals within vein breccia is sporadic and not understood. Samples of apparently unmineralized host sedimentary rock were taken and were found to carry grades greater than 300 parts per billion gold including assays of up to 1.31 grams per tonne.
The area is characterized by strong silica clay (±biotite) alteration directly surrounding the main silicified zone for approximately 15 to 20 metres. This zone is flanked by a zone of weak to medium clay chlorite alteration, which pervasively alters the rock throughout the whole of the South King Salmon Lake area.
The following work history is discussed with respect to the 2004 Sutl claim group of Rimfire Minerals Corporation which provides a locational reference to work in the area. Refer to Assessment Report 27589 for the location of the Sutl claims.
The earliest recorded work on the Sutlahine property was carried out in 1969 by the Taku Syndicate, a 5 company joint venture. No data is available from this program, but it is reported (Assessment Report 2537) that copper and molybdenum anomalies from silt samples occur in creeks “radiating from slopes of the cirque valley” on the Sutl 5 and 7 claims (Assessment Report 27589). Taku carried out a ground magnetic survey over this area the following year, distinguishing vertical, northeast trending magnetic lineations corresponding to magnetic feldspar porphyry dikes. Noranda carried out a one day reconnaissance of the same ground in 1986 (Assessment Report 15477). They reported bleached and silicified zones flanking felsic dikes with maximum values of 70 parts per billion gold, 13.2 grams per tonne silver, 1.3 per cent lead and 0.62 per cent arsenic.
Cominco Limited conducted a regional reconnaissance program in 1988. It is not known how many samples and from where sampling was conducted, however, a sample of quartz arsenopyrite vein was collected on the Bryar property (the Sutl 13 16 claims of Rimfire in 2004), which assayed 17.043 grams per tonne gold (Assessment Report 19326). The ground was staked one year later, in order to follow up on the sample. During the 1989 program, several thin quartz-arsenopyrite-pyrite veins were found to have been predominantly hosted in quartz-biotite-feldspar porphyry and to a lesser extent in the adjacent hornfelsed clastic sedimentary rocks. These sedimentary rocks were hornfelsed by this porphyry.
Solomon Resources Ltd staked a package of King claims in 1990 (corresponding to the western half of the 2004 Sutl 5 12 claims of Rimfire and extending westward). Solomon concentrated on two gossans (Assessment Report 21530): Zone C is in the same cirque on Sutl 5 and 7 where Taku and Noranda did their work; and Zone A on Sutl 9 and 11. (Gossan B is on Sutl 1 4 claims on the current area covered by the Thorn property to the southeast.). In Zone A, Solomon recognized a highly silicified and pyritic hornblende granodiorite, with traces of molybdenite, intruding sediments and andesitic pyroclastic rocks, themselves silicified near the contacts. Several styles of mineralization were recognized in Zone A, including a 1-metre fault zone (maximum values of 100 parts per billion gold, 416 grams per tonne silver, 7.1 per cent copper) and skarn (maximum values of 210 parts per billion gold, 103 grams per tonne silver, 0.87 per cent copper, 1.52 per cent lead and 4.36 per cent zinc) (Assessment Report 21530). A silt sample with 1220 parts per billion gold was taken from the projected strike of a lineament hosting a chalcedonic quartz carbonate breccia zone up to 5 metres wide. One sixth of the soil samples from Zone A exceeded 50 parts per billion gold, with maximum values of 490 parts per billion gold, 130.6 grams per tonne silver, 2.06 per cent copper, 0.36 per cent lead and 0.57 per cent zinc (Assessment Report 21530). In Zone C, Solomon mapped hornfelsed pelitic rocks intruded by locally sericitized hornblende granodiorite, quartz feldspar porphyry, quartz porphyry and monzonite. The more leucocratic varieties contain disseminated molybdenite. The most spectacular gossans are in creek gullies, exposed for up to 100 metres; exposures are fractured, sheared, silicified and locally argillized. Solomon described three 15-centimetre-wide quartz carbonate veins from Zone C, the best of which returned 0.41 per cent copper, 0.19 per cent lead, 0.76 per cent zinc, 167 parts per million arsenic, 9 parts per billion gold and 38 grams per tonne silver (Assessment Report 21530).
In 1991, Omega carried out limited mapping and geochemical sampling on their claim group property (the Sutl 6 and 8 claims of Rimfire in 2004) immediately east of Solomon’s King. Results were generally low, with maximum soil values of 70 parts per billion gold, although a base metal anomaly (maximum 0.12 per cent zinc, 0.33 per cent lead, 0.053 per cent copper and greater than 0.2 per cent arsenic) was reported within a gossan straddling the contact zone between granodiorite, quartz feldspar porphyry and volcanic rocks (Assessment Report 21907).
Rimfire Minerals Corporation acquired the property in 2003 and early 2004 aiming to explore for similar mineralizing styles observed on the nearby Thorn property, including high sulphidation epithermal gold silver copper mineralization and breccia hosted silver gold lead mineralization.
During June 2004, Rimfire initiated a regional geological mapping, prospecting and soils and silt sampling program on the LJ and Sutlahine claims, collecting 85 rock -, 92 silt - and 504 soil samples (Assessment Report 27589).
In 2005 the Kizmet project was optioned to Barrick Gold Corporation who expanded the property and explored its large claim holdings (including the Sutlahine claims of Rimfire Minerals.) that extended from Tatsamenie Lake northwest to the Taku River. The property covered a 70 by 20 kilometre area. Barrick collected 848 rock -, 46 stream sediment - and 31 soil samples. Results from the field season were generally poor.
Barrick terminated the option at the beginning of 2006.
During the 2007 field program, Rimfire Minerals collected a total of 19 rock -, chip - and channel samples in the Sutl showing area to systematically evaluate encouraging reconnaissance rock grab samples from the zone of silicified vein breccia discovered in 2004 on mineral tenures 502803 and 502815.
