The True Fissure property is located 38 kilometres east-northeast of Hazelton, on the south side of Mount Thoen. The property is developed by two short adits and several shallow trenches.
The area is underlain by Middle Jurassic to Lower Cretaceous Bowser Lake Group sandstones and siltstones which strike 170 degrees and dip 40 degrees west. Northwest of the vein, the sedimentary strata are intruded by granodioritic rocks of the Mount Thoen stock, an apophysis of the Late Cretaceous Bulkley Intrusions. A contact metamorphic hornfels is developed around the intrusion.
The True Fissure vein strikes at 060–080 degree azimuth and dips 60 degree to the southeast. It is intermittently exposed over a length of 600 metres and a vertical distance of 300 metres. It ranges in thickness from 0.33 to 0.88 metre and forms a lens 100 to 200 metres in length within the shear zone. Mineralization consists of galena, sphalerite, pyrite, chalcopyrite, arsenopyrite and tetrahedrite in a gangue of quartz and carbonate. The vein has been exposed on the Thoen 4 claim over a 130 metre strike length and a 60 metre vertical extent in a cliff, with an average width of 0.50 metres.
The weighted average of samples taken from the western part of the vein over an average width of 0.50 metres is 1155.6 grams per tonne Ag, 0.6856 gram per tonne Au, 7.5 per cent Zn and 2.66 per cent Pb (Assessment Report 13091).
The TH property is situated on the northwestern side of Thoen Mountain and was originally located in 1967. The True Fissure vein lies approximately 2 kilometres to the southeast of the TH property. In 1970, the property was being explored by Manex Holding Limited. Exploration on the property by 1970 consisted of six rock trenches and occasional pits over a 100 metres. The weighted average of assays selected for a preliminary evaluation was 0.35 per cent Cu, 0.044 per cent Mo, 8.6 grams per tonne Ag and 0.35 gram per tonne Au (Property File Cyprus Anvil Sharp, W.M., 1970).
Work History
From 1922-1929, J.A. Rutherford and Gordon McLennan worked the True Fissure group. The True Fissure vein was developed by a short tunnel and several trenches. In 1929, J.A. Rutherford had gained control of the properties around the peak of Mount Thoen. The mineral showings in the area were examined by Douglas Lay, resident mining engineer for the North-eastern Mineral Survey District. The tunnel on the True Fissure vein had been driven in 9.8 metres from the portal along the vein.
No other recorded work is available until Mr. Lorne Warren of Smithers staked the claim in 1979. Mr. Warren optioned the claims to D. Groot Logging Ltd in 1980. D. Groot Logging conducted a 10 day exploration program of geological mapping, chip sampling and a Self-Potential survey on the Thoen 1-4 claims.
In December 1982 the claims were purchased by Mr. Richard Barclay of Langley and vended to Amir Mines Ltd. A property examination was carried out on 1983. Amir Mines Ltd. contracted Bema Industries Ltd. to carry out a 4 day property examination. Work was carried out on the known True Fissure silver vein outcrops on Thoen 1-4 claims. A program of stream silt sampling, geological mapping and rock chip and grab sampling was conducted.
From 2005 to 2013 the Daniel Merkley and William Merkley were owners of the True Fissure claims. In 2013, two samples were taken by owners William and Daniel Merkley in 2013.
There are possibly 2 veins on the property rather than one; possibly transecting at a point near the middle trench, which is approximately 170 metres above the adit. This is evident by the appearance of two gossanous fissures on the rock face above the old workings. The one vein apparently dips steeply to the northeast; the other dips steeply to the southwest.
