The Thorne occurrence is located approximately 4.5 kilometres east-southeast of the southern tip of Thorne Lake about 169 kilometres north-northwest of the community of Germansen Landing.
The showing is hosted in Upper Triassic Savage Mountain Formation (Takla Group) mafic to intermediate volcanics. In this area, the Savage Mountain Formation is bounded to the west by the northwest trending Moose Valley fault and to the east by an Early Jurassic quartz monzodiorite intrusion.
Mineralization consists of chalcopyrite and sphalerite with associated pyrite in rusty shear zones and quartz-carbonate veins. The shear zones and veins cut mafic to intermediate volcanics which have been locally intruded by hornblende and feldspar porphyries. The volcanics are fractured and exhibit propylitic alteration. Malachite and azurite commonly stain the shears and veins.
In 1984, three grab samples, two from rusty shear zones and one from a rusty mafic volcanic, assayed 3.2, 0.675 and 0.705 grams per tonne gold, respectively (Assessment Report 13001).
In 2016, Copper North Mining Corporation carried out reconnaissance geological mapping and prospecting. Three diamond-drill holes were drilled on the Thor property. The first hole (TH16-01), located about 600 metres south of the rusty shear zone sampled in 1984, intersected low grade copper-gold porphyry-style mineralization with disseminated and vein-hosted chalcopyrite-pyrite with 157.5 metres of 0.11 per cent copper and 0.037 gram per tonne gold including 23.85 metres of 0.28 per cent copper and 0.087 gram per tonne gold. The second hole was lost in overburden. The third hole intersected 228.9 metres of brick red tuff breccias tentatively correlated with the Toodoggone Formation of the lower Hazelton Group and no copper mineralization was encountered (Assessment Report 36698).
The Thor-Marmot property totals approximately 110 square kilometres (ca. 2018) and covers six occurrences (Thor, 094D 064; Thorne, 094D 126; Thorne Lake, 094D 127; Inca, 094D 129; Thorne Creek, 094D 131; and Marmot, 094D 005).
Within the Moose Valley-Marmot area, mineralization of interest was first reported during a regional mapping program of the Geological Survey of Canada in the early 1940s. The first claims were staked in the early 1960s by W.D. Savage, and optioned in 1966 to New Wellington Resources Ltd. In 1965, prospecting and a limited amount of shallow surface trenching had exposed six vein zones. The zones varied in width from 0.75 to 4.5 metres and were indicated for a length up to 900 metres. Sampling of vein material returned copper values in excess of 3 per cent and silver up to 274 grams per tonne. A sample from the intersection of two mineralized zones returned gold values from 24.7 to 63.1 grams per tonne (Property File Cyprus Anvil - Holbrooke, G.L., 1965). Two samples from the disseminated copper mineralization in 1966 returned values of 1.10 per cent copper over 1.2 metres and 0.65 per cent copper over 7.5 metres (Property File Cyprus Anvil - Stevenson, W. G., 1966). In 1966, New Wellington completed a program consisting of geological mapping, induced polarization (IP) surveying (two lines across the Marmot showing), and bulldozer trenching. A total of 767 metres of trenching was completed, and about 8 hectares of bedrock was stripped. In 1967, a further 1.6 kilometres of bulldozer stripping was completed, and one short hole was drilled. In 1969, the property was optioned by Texada Mines Ltd., who carried out a program of soil sampling and geological mapping. Five diamond-drill holes totalling about 238 metres were drilled, three of which were on the main Marmot showing and the other two on the slope immediately to the west. Due to reported technical difficulties, none of the holes reached their target depth. A total of 2066 soil samples were taken.
In the early 1970s, BP Minerals, after a regional stream sediment survey, staked several claims in the central Thor area north of the present Marmot claims. In 1973, Wesfrob Mines Ltd. (a Falconbridge subsidiary) optioned the Marmot property and in 1973 carried out a 300 line kilometre airborne magnetic electromagnetic (EM) survey, and a 275 metre, five hole diamond drill program. Two of the drillholes were drilled to determine depth to bedrock, and two other holes tested weak
VLF-EM conductors in readily accessible areas. No mineralization of interest was encountered. The fifth hole, drilled below one of the known Marmot mineralized zones, showed no values of interest although core recovery was very poor. The airborne survey, consisting of magnetics and electromagnetics, did outline a possible buried porphyry or semi-massive sulphide target within rocks of unknown derivation, as well as generating many EM anomalies believed caused by carbonaceous beds. No drill testing of anomalies was carried out, as Wesfrob postponed further work on its main priority, the Sustut copper property, leaving the area late in the season.
In 1984, BP Resources carried out a program of silt and rock chip sampling as a follow up to their earlier program in the central claim area. Also in 1984, Falconbridge carried out an exploration program in the Moose Valley area (including the north part of the current Thor claims) targeting palaeoplacer gold deposits in the clastic sediments of the Sustut Group. Copper- and gold-bearing shears hosted in volcanic rocks on the Thor 3 claim were also investigated. During 1987, Mingold Resources Ltd. re-staked the property as the KMA claims and conducted a small sampling program. The next year a small soil geochemical program west of the known showings outlined a copper and gold soil anomaly. In 1988, a program of rock sampling, prospecting and soil sampling was carried out on the more northerly Thorne claims by Asamera Minerals Inc. Additional claims were staked in 1989 and further soil and rock sampling completed, but further test recommendations submitted to Asamera were not followed through on.
In 1990, Mingold Resources carried out further exploration consisting of rock and soil sampling near the Marmot prospect, extending the copper and gold anomalies to the north, and to the south. Surface sampling has yielded 6.51 grams per tonne gold, 80.6 grams per tonne silver and 1.23 per cent copper over 3.5 metres (Property File Placer Dome - Mingold Resources Inc., 1990). In 1992, Electrum Resources Corporation staked the Thor 1-7 group of claims several kilometres to the north, covering much of the abandoned Thorne ground, and eventually consolidated a new Thor group in 1995 contiguous with the Marmot (1992) property to the south. Work by Electrum consisted of geochemical and VLF-EM surveys, largely designed to trace important fault structures southward from the Kemess copper-gold porphyry deposit. In 1995, on behalf of Electrum Resource Corp., a soil and rock sampling program as well as a VLF-EM survey was conducted in an attempt to better locate the Moose Valley fault zone which traverses the length of the claims. In early 1997, San Telmo Resources Ltd. optioned the Thor 2, 3, 8, 9, and Marmot claims from Electrum and staked the Thor 11, Thor 12, and Marmot 2 claims. In March of 1997, San Telmo completed an airborne geophysical survey (EM and magnetics) over the area. In 1998, San Telmo contracted a small amount of geological mapping and rock sampling as well as 692.21 metres of diamond drilling. Results from the drilling included a 60.24-metre intersection grading 0.112 per cent copper and 0.041 gram per tonne gold (George Cross News Letter No.146 (July 30), 1998).
In 2005, Electrum Resource Corp. conducted geochemical rock, soil and drainage sampling on the Thor property in order to identify geochemical anomalies for porphyry-type copper-gold mineralization. As well, drill core from the 1998 program was resampled and reanalyzed. Three lines of IP and ground magnetic surveys were carried out in the central part of the Thor claims, from the Kemess mine road to the alpine slopes to the east. In 2007, three additional lines of IP and ground magnetic surveys were carried out. In 2009, Quantec Geoscience Ltd. conducted a Titan-24 survey over the two of the 2007 IP lines.
In 2013, Electrum Resource Corp. conducted a ten-day soil sampling program on the Thor claims, sampling a total of 216 sites. In 2014, Copper North Mining Corp. signed an agreement to acquire a 100% interest in the Thor property from Electrum Resource Corporation. In 2014, Copper North Mining Corp. conducted 39.8 line kilometres of IP and magnetic surveys on the Thor property. In 2016, Copper North engaged Condor Consulting to perform 3D magnetic inversions, integrating several historic magnetic datasets. In Summer-Fall 2016, Copper North carried out reconnaissance geological mapping and prospecting. Three diamond-drill holes were drilled on the Thor property. The first hole intersected low grade copper-gold porphyry style mineralization with disseminated and vein-hosted chalcopyrite-pyrite with 157.5 metres of 0.11 per cent copper, 0.037 gram per tonne gold including 23.85 metres of 0.28 per cent copper and 0.087 gram per tonne gold. The second hole was lost in overburden. The third hole intersected 228.9 metres of brick red tuff breccias tentatively correlated with the Toodoggone Formation of the lower Hazelton Group and no copper mineralization was encountered. In 2018, Electrum Resource Corporation completed an airborne LiDAR topographic survey and subsequent desktop surficial geological mapping, interpretation and recommendations for geochemical sampling.
