The Knob Hill prospect is situated 0.5 kilometre southwest of Bell Creek, on the northwest side of the Similkameen River and 35 kilometres south-southwest of Princeton.
The area is underlain by Upper Triassic Nicola Group volcanics, which are composed of a varied assemblage of volcanic flows and pyroclastics with associated clastics with minor limestone. These rocks are metamorphosed to greenschist facies in a 5 to 6 kilometre wide northwest-trending belt that parallels the eastern margin of the Late Jurassic to Early Cretaceous Eagle Plutonic Complex granodiorite. The resulting chloritic and sericitic schists strike 165 to 180 degrees, with an average dip of 65 degrees west. The Nicola Group is unconformably overlain by the Eocene Princeton Group rocks composed of basaltic and andesitic flows, pyroclastics and agglomerates.
The prospect is hosted in a sericitic and talcose schist within a sericite and sericitic chlorite schist sequence. Silicification varies from moderate to extreme. Silica-rich lithologies tend to exhibit boxwork textures.
Mineralization occurs in two shear zones, 2.4 and 1.8 metres wide, respectively, exposed in a west-trending adit. The zones are 17 metres apart. The easternmost zone also occurs on surface, 15 metres above the adit. Both strike 165 to 172 degrees and dip 33 to 53 degrees southwest, conformable to the enclosing schist.
These zones are silicified with sugary quartz, accompanied by abundant pyrite, some chalcopyrite and chalcocite, and minor hematite, malachite and azurite. Chalcocite occurs as a coating on pyrite. One drillhole intersected 'heavy sulphides' on the downdip projection of both zones but failed to intersect significant copper mineralization (Assessment Report 878). A selected grab sample assayed trace gold, 20.6 grams per tonne silver and 9.6 per cent copper (Minister of Mines Annual Report 1927, page 250). A sample of pyritic, sericitic material taken from the adit dump assayed 1 gram per tonne gold, 80.2 grams per tonne silver, 7.43 per cent copper and 0.659 per cent zinc (Assessment Report 21491, page 16, sample 95806).
Exploration in the immediate vicinity of the shear zones encountered widespread disseminated sphalerite in addition to disseminated and stringer pyrite in quartz veins, metasediments and siliceous rocks. Four samples assayed 0.27 to 0.79 per cent zinc and trace to 0.03 per cent copper (Assessment Report 878, page 4). Magnetic surveys completed in 1993 and 1994 indicated that the favourable volcanic rocks that host the Knob Hill occurrence may extend to the north and south. A very low-frequency electromagnetic conductor is also present along strike from the Knob Hill occurrence in an area referred to as the Knob Hill grid area. Subsequent soil sampling in the Knob Hill grid area outlined a narrow copper (up to 414 parts per million) and zinc (up to 1170 parts per million) anomaly coinciding with a barium anomaly (up to 2220 parts per million).
Exploration work has been conducted in the Bell Creek area since 1900. Most of this work has been focused on several showings near the eastern boundary of Manning Provincial Park, just north of Eastgate, British Columbia. The Redstar (MINFILE 092HSE067) has received the most exploration attention, although the Knob Hill, Golden Crown (MINFILE 092HSE191) and Paw (MINFILE 092HSE093) have also been explored.
The Knob Hill prospect was first explored by John Bowman between 1920 and 1927. Bowman excavated a 48-metre long crosscut adit and several opencuts and trenches. In 1920, an adit driven into mineralized outcrop on the Knob Hill claims had exposed an entirely new, well-mineralized ore body approximately 3 metres in width. Work continued with a crosscut tunnel driven at 15 metres elevation below the opencut and shaft. In 1924, a crosscut tunnel developing two veins, 1.2 and 1.8 metres wide, respectively, was driven 47.9 metres into schist.
Between 1966 and 1970, Spenho Mines Limited carried out an exploration program of geological mapping, soil sampling, diamond drilling and magnetometer and horizontal-loop electromagnetic geophysical surveying over the Knob Hill and Red Star claim area. Two diamond drill holes totalling 365.76 metres were completed in the Knob Hill claim area.
In 1980, Cominco Limited optioned the claims covering the Red Star occurrence from Carl Wabnegger and conducted a comprehensive exploration program for volcanogenic massive sulphide deposits. Exploration consisted of mapping, soil geochemical sampling and induced polarization, magnetometer and very low-frequency geophysical surveying. A strong electromagnetic conductor coinciding with an induced polarization conductor was defined. Weak copper and zinc soil anomalies associated with the favourable Red Star horizon were also coincident with geophysical results.
From 1986 to 1987, Bukara Resources Limited completed additional geological, geochemical and geophysical exploration, including 1100 metres of trenching and induced polarization resistivity geophysical surveying. Work focused on gold-bearing pyritiferous schists in the Red Star horizon. The Red Star massive sulphide lens was excavated over caved underground workings. Assays returned less than 0.4 gram per tonne gold (Assessment Report 25443, page 8) causing Bukara to drop the option on the property.
In 1990, the Red Star occurrence and surrounding area were restaked by Pamicon Developments Limited. Many of the old surface workings, including the massive sulphide lens, were resampled and mapped. In 1992, Westmin Resources Limited optioned the claims from Pamicon Developments and conducted a comprehensive two-phase exploration program consisting of reconnaissance-scale geological mapping, lithogeochemical and stream sediment sampling. In 1993, Westmin Resources laid a 43.1 line kilometre grid out over the Red Star and Knob Hill area and conducted geological mapping, geochemical sampling and geophysical surveying. The following year, the grid was extended to the east and additional soil sampling and geophysical surveying were completed. Five diamond drill holes totalling 1406.34 metres were drilled across stratigraphy north of the Red Star showing. Further work was recommended; however, Westmin Resources allowed the option to lapse in 1995.
In 1997, Teck began a planned 1200-metre drilling program to earn a 70 per cent interest in the property from Redstar Resources. In total, 1515.6 metres were drilled in five holes beneath and along strike to the south of the Red Star showing.
In 2012, property owner Christopher Delorme conducted a reconnaissance exploration program aimed at locating and geochemically assaying reported mineralization at the old workings. In total, 15 rock samples were collected from the historical workings, including adit faces and waste dump float. One sample taken from the adit dump at the Knob Hill prospect returned anomalous copper values. From the 2012 sampling program, sample 11 from the Knob Hill prospect returned 0.18 per cent copper (Assessment Report 33378, page 5).
