The Tsacha prospect, part of the 3Ts property (093F 055, 68) of Southern Rio Resources Ltd. encompasses a northerly trending, low sulphidation epithermal gold-silver quartz vein system. The gold-silver-copper prospect consists of several quartz vein and stockwork veinlet occurrences found in the vicinity of Tommy Lakes, about 125 kilometres southwest of Vanderhoof. The veins occur in welded rhyolitic flows and lesser ash-flow tuff of the Middle Jurassic Hazelton group (Entiako Formation).
Dark green feldspar and augite-phyric basaltic andesite flows of the Naglico Formation conformably overlie the welded tuff. A medium grained augite porphyry plug is probably cogenetic with the flows. Minor volcanic-derived calcareous siltstone, sandstone and conglomerate, with abundant plagioclase grains and local argillaceous beds, crop out immediately north of the augite porphyry plug. They are derived primarily from the felsic volcanic rocks of the Entiako Formation, but also contain clasts of augite porphyry. Sills and dikes of microdiorite intrude the Jurassic rocks and crosscut the epithermal vein system. A sample of the sill yielded a U-Pb zircon date of 73.8 +2.9/-0.1 Ma, indicating latest Cretaceous emplacement (R.M. Friedman, personal communication, 1996).
The occurrences were discovered during regional mapping by crews from the British Columbia Geological Survey in 1993. The Tsacha 16-unit claim block was staked by Teck Corporation in 1994 to cover these showings. Teck conducted soil geochemistry, prospecting, trenching and rock chip sampling in 1994. Work confirmed four veins and a vein-stockwork zone.
The main vein (Tommy) strikes approximately 020 degrees, dips vertical to steeply west and has been traced over 650 metres and remains open along strike. The vein has an average width of 4 metres and is continuous downdip to a diorite sill at 120 metres. The quartz is white, finely crystalline to massive, rarely banded along vein margins with drusy crystals growing inward toward the centre of some anastomosing veinlets. Sparry calcite sometimes occupies a void at the centre of the banded veins. Vein mineralogy includes native gold, stephanite, electrum and argentite in quartz, adularia, carbonate and montmorillonite. Pyrite is present in trace amounts. Alteration consists of silicification, hematization with clay and sericite occurring distally. In 1993, a grab sample from the main (largest) vein assayed 34.8 grams per tonne silver and 3.3 grams per tonne gold (Open File 1994-2). Values greater than 1 gram per tonne gold have been obtained along the entire exposure of the vein (Cordilleran Roundup Abstracts February 7-10, 1995).
Stockwork veinlets are exposed on a knoll due south of the easternmost of the Tommy Lakes. Prominent fractures and brecciated vein material trend northeast. Another system of stockwork veinlets crop out on a knoll near the centre of a recent forest burn, northeast of Tommy Lakes. These quartz veins are similar to others south of Tommy Lakes, however, they also contain crystalline barite.
Work in 2012, north of the Johnny and Billy veins, quartz vein boulders were sampled. Wallrock contains 4 to 5 per cent quartz veinlets in outcrop 100 metres north of the Johnny Vein; these veinlets contain traces to 1 per cent disseminated pyrite and rare galena. No outcrop or quartz vein float was observed south of either the Johnny Vein or the Billy Vein. The Johnny Vein is very well exposed. The area to the west of the Johnny Vein remains relatively unexplored. The Alf Vein to the north is a 20 centimetre wide vein that extends for 20 metres along strike. The Alf Vein is clay rich, and the adjacent RQFP wallrock hosts minor amounts of breccia and quartz veins. No vein extensions were discovered during the work at the Alf Vein area. Additional work areas at the 3Ts property included the Goofy Vein area, and eastwards from there, towards the Ted Vein.
In 1994, Teck conducted geological mapping (1700 hectares); rock (207 samples), silt (11 samples) and soil (413 samples) geochemistry; and trenching (17 trenches). Values consistently over 1 gram per tonne gold were obtained along the entire exposure of the vein, with a maximum value of 61.9 grams per tonne gold and 292.5 grams per tonne silver over 1.5 metres from a trench sample (Assessment Report 23881). A resource calculation for the Tommy Vein is 478,600 tonnes grading 8.7 grams per tonne gold and 82.3 grams per tonne silver, using a 3 grams per tonne cut off (MEG talk, February 19, 1997); calculation based on 27 drill and 9 trench intersections (Exploration in British Columbia 1998, page B-8).
The adjacent Tam and Taken claim groups (093F 068) (west and northwest, respectively) host mineralized quartz veins of the same character as the Tsacha veins (i.e., all related to the same system approximately 2 kilometres wide).
In 1995, with Explore B.C. Program support, Teck Exploration Ltd. completed 1970 metres of diamond drilling in 20 holes, 240 metres of excavator trenching and a program of rock and bark geochemistry. This work traced the Tommy Vein 590 metres along strike and 100 to 200 metres downdip, leaving it open in all directions. The work also determined that the Larry Vein has potential of having the same continuity as the Tommy, with possibility of economic ore shoots. This property has good potential for a bonanza-style epithermal deposit of the adularia-sericite type (Explore B.C. Program 95/96 - M110).
In 1996, Teck completed approximately 3365 metres of diamond drilling in 23 holes. Drilling focussed on veins other than the Tommy. Trenching was also done across two kilometres of veins in an east-west direction; at least 8 veins have been identified. Drilling also tested the Johnny Vein (discovered in 1995), located approximately 600 metres west of the Tommy Vein, the Barney Vein (1996) located east of the Tommy Vein near the property boundary, and the Larry and Billy veins. All vein systems strike north-south and have a near-vertical dip.
As of January 1997, work completed consisted of 1600 metres of trenching (40 trenches) and 8300 metres of diamond drilling (58 holes), resulting in the discovery of seven veins (Tommy, Larry, Johnny, Ian, Bobby, Barney, Goofy and Alf). In October 1997, Corona Gold Corporation entered into an agreement with Teck Corporation to earn a 50 per cent interest in the property. Corona drilled 15 holes, totalling 5926.5 metres in 1998.
Deep diamond drilling in 1998 traced the Tommy Vein along strike, below the sill, for over 170 metres, and downdip for over a 100 metres. The true width of the subsill vein intersections range from 0.7 to 9.35 metres. Gold assays are fairly consistent in the 1 to 10 grams per tonne range (Exploration and Mining in British Columbia 1998, B1-B10).
The 3Ts Project of Southern Rio Resources Ltd. consists of the Tsacha property (093F 055) optioned from Teck-Cominco Ltd., the 100 per cent owned Tam property (formerly owned by Cogema) (093F 068) and Taken property (093F 068) optioned from Phelps Dodge. The Tsacha and adjoining Tam and Taken properties cover a number of outcropping gold-silver quartz vein systems. For the purposes of MINFILE, the Tommy Vein, Larry Vein and Tommy North Vein, which all occur on the Tsacha claim, are assigned to that MINFILE designation. The Ted Vein, Ted East, Corner Zone, Adrian West, Adrian Creek, Mint Vein, Ringer zone and Triple Junction form more of an eastern cluster on the Tam and Taken claim.
Southern Rio drilled two holes that intersected the main Tommy Vein at 200 metre and 400 metre step-outs, and extended the known strike length of the structure to more than one kilometre.
Southern Rio released an inferred mineral resources estimate in 2002 of 470,700 tonnes grading 7.40 grams per tonne gold and 65.22 grams per tonne silver. This estimate is based on a 4 grams per tonne gold cut-off grade and it meets National Instrument (NI) 43-101 standards (November 18, 2002 News Release, www.sedar.com).
In November 2004, a program of approximately 4000 metres of diamond drilling started on the 3Ts property. This work, which continued to late February 2005, was the largest single drilling program to date by Southern Rio. The first hole of the program identified the depth extension of the Ted Vein (see 093F 068). Elsewhere, holes at the Tommy Vein also encountered mineralization beneath the sill and along strike (hole TS-05-108).
In 2005, Southern Rio changed their name to Silver Quest Resources. In 2006, the company conducted a drill program and their website reports inferred resources for the Tommy Vein of 668,850 tonnes grading 6.07 grams per tonne gold and 55.2 grams per tonne silver and for the Ted vein (093F 068) of 273,800 tonnes grading 2.0 grams per tonne gold and 133.0 grams per tonne silver (www.silverquest.ca).
In 2011, Silver Quest Resources completed a drill program on the 3Ts property, focussed on the Ted, Mint, and Ringer sites (093F 068). They released an inferred resource for the Tommy Vein (calculated only above the shallow dipping microdiorite sill that crosscuts the vein structure) of 552,500 tonnes grading 6.82 grams per tonne gold and 60.9 grams per tonne silver, at a 3.0 grams per tonne gold cutoff (Assessment Report 32671). Independence Gold Corp. acquired the 3Ts property from Silver Quest Resources in December 2011.
In 2012, a NI 43-101 compliant inferred resource estimate has been calculated for the Tommy, Ted and Mint veins (093F 068). Using a 1 gram per tonne gold grade cut-off, the total inferred resource for these three veins is 3,614,072 tonnes grading 3.39 grams per tonne gold and 85.15 grams per tonne silver for 11,180,560 contained grams of gold and 280,513,624 contained grams of silver (Press Release, Independence Gold Corp., January 20, 2012).
In 2012, Independence Gold Corp. collected rock samples across their 3Ts property which included veins at the Tsacha (093F 055) and Tam (093F 068) prospects. At the Tsacha prospect, the Johnny and Billy veins are the two most westerly veins found to date. Prospecting, geological mapping and rock sampling were performed both to the north and to the south of these veins. Sampling work was also done in the Ian, Goofy and Alf vein areas. Two diamond-drill holes were completed in the Ted veins area on the Tam prospect.
In 2013-14, Independence Gold drilled the Ted-Mint gap area, Ted Vein, and the Larry and Tommy veins (2683 metres were drilled in 2014).
In 2016, Independence Gold Corp. conducted an MMI and B-horizon soil geochemical sampling program following the release of the 2015 Geoscience BC spruce top biogeochemical survey results that show gold, arsenic, and zinc anomalies in the up-ice (west) direction from the known vein system. Soil sampling included an orientation survey and some regional sampling with the aim of developing targets in new areas. Prospecting continued in the area of known veins. In 2017, Independence Gold completed an MMI soil survey that identified new drill targets. The company is seeking a partner for 2018.
In 2017, Indicated resources at the 3Ts project are 5.452 million tonnes at 2.52 grams per tonne gold and 71.5 grams per tonne silver (Information Circular 2018-1, page 46).