The Mount Thomlinson property is located on the north side of Mount Thomlinson Mountain Range, 5 kilometres north of Thomlinson Peak, and 40 kilometres north of Hazelton.
Massive black argillaceous siltstones and argillites of the Middle Jurassic to Lower Cretaceous Bowser Lake Group have been intruded by a roughly circular stock (1400 metres diameter) of leucocratic quartz monzonite porphyry of the Eocene Babine Intrusions. Near the contact, the sedimentary rocks have been deformed and metamorphosed to medium or dark grey schists in a zone 91 to 152 metres wide. Stock contacts are sharp and biotite, muscovite, cordierite and andalusite have been formed in the contact aureole. The margins of the stock are foliated parallel to the contact and to the schistosity in the intruded rocks up to 100 metres from the contact. Much of the stock is a coarse-grained porphyry with potassium feldspar phenocrysts up to 5 centimetres long. In many areas, the stock is cut by narrow (2-10 centimetres) aplite dikes. These dikes occur in swarms and occupy well-defined fractures. A potassium-argon age date from biotite from the stock resulted in an age of 54 Ma (Geological Survey of Canada Open File 2322).
Molybdenite, chalcopyrite and pyrite are associated with a system of quartz vein stockworks within the intrusive, along the contact hornfelsed zone with the argillaceous rocks. The quartz stockwork is best developed along this stock contact and post-dates the aplite dikes. The mineralized zone trends north-northeast (030 degrees) along the margin of the stock, and dips 58-65 degrees west. It is tabular and up to 100 metres wide. Molybdenite is most common as fine flakes in quartz veinlets and as smears along fracture planes. Locally it occurs as coarse flakes in quartz veins. Weathering of mineralization has been considerable, and in many areas extends from 60 to 91 metres below the surface. Limonite, ferrimolybdite, malachite and to a lesser extent, azurite, are the principal secondary minerals. Chalcopyrite, malachite and azurite also occur along fractures and veins. Although chalcopyrite is found in the same general areas as molybdenite, the two sulphides occur independently of each other. Pyrite (1-5 per cent) is found as disseminations, fracture-fillings and patchy crystalline concentrations in the intrusive and adjacent argillites. Minor amounts of magnetite, scheelite and pyrrhotite are also evident. The better grade rock lays several metres from the contact within the intrusive rock. In general the mineralization extends farther into the intrusive than into sediments, and in many places the amount of mineralization drops off sharply at the contact.
Although mineralization has been found over a strike length of 900 metres, the width and grades vary considerably. The zone becomes more complex and less well-defined to the northeast with narrow sections of mineralized rock separated by relatively barren rock. Deposition of sulphides appears to have been largely controlled by this northwest dipping zone of fracturing and shearing.
Alteration within and close to the mineralized zone comprises substantial silicification with argillic and chloritic assemblages and sericitic overprinting.
Measured, indicated and inferred reserves are 40.82 million tonnes grading 0.071 per cent molybdenum (0.12 per cent MoS2)(CIM Special Volume 15 (1976), Table 3, page 422). Conversion to Mo using the factor 1.6681.
Exploration of the Mount Thomlinson property has been carried out by several operators including: Buttle Lake Resources, Southwest Potash Corp. (a subsidiary of AMAX) and Texasgulf. The main periods of exploration occurred from 1963 to 1965 and 1980 to 1981.
Information for the 1962 to 1965 work programs was obtained second-hand from the history section of Texasgulf assessment report 7916.
The area was originally staked in 1962 by three prospectors (Neil Sterritt, Ward Marshall, and Harry Simpson) from Hazelton and optioned to Buttle Lake Mining (later Stampede International Resources Ltd). In 1963 the property was mapped, trenched, and sampled by Buttle Lake Resources. In August of 1963, Southwest Potash Corporation optioned the property. Loudon (1963) spent nine days on the property, produced a map, and recommended the option.
In 1964 and 1965, Southwest Potash Corporation conducted programs of geological mapping, surveying, geochemistry, and drilled nine BQ diamond drill holes totalling 2,459 metres. The core was not assayed for copper, gold or rhenium. The property was subsequently allowed to lapse and was re-staked by AMAX in 1975, which had changed its name from Southwest Potash Corporation.
In 1979 the property was restaked as the Molly Tom claims by John Bot, an independent prospector from Smithers. Mr. Bot optioned the property to Texasgulf. Texasgulf examined the property in preparation for a drill program planned for 1980.
Work performed by Texasgulf in 1980 included construction of a camp and drill site and diamond drilling of one NQ drill hole (T-1-80). The hole was abandoned at 213 metres, about 500 metres short of the projected target depth because of difficult ground conditions. The diamond drill hole intersected strongly fractured Bowser Lake Group argillite/shale with sparse quartz, calcite veinlets and finely disseminated pyrite.
In 1981, Texasgulf drilled four NQ diamond drill holes totalling 1,632.3 metres from a single common set-up location.
In 1993, Discovery Consultants re-sampled surface showings and selected core samples for assay. Core re-sampling was carried out on drill hole 1981 drillholes.
In 2004, Cadre Capital Inc. (Cadre) staked the area. In September 2005, Cadre collected 33 rock samples in four different areas. Cadre subsequently sold the property to MolyStar Resources Inc.
In 2007, MolyStar moved the core from the campsite on Mount Thomlinson to a warehouse in Smithers. The core was re-logged and re-sampled, with 272 samples selected from Texasgulf hole T-2-81. No significant new zones of molybdenum mineralization were encountered.
In 2010, R.H. McMillan visited the property for Hi Ho Silver Resources and selected three “grab” samples for assay. Several blue-green stained areas were sighted during this year’s program but not visited.
In 2011, a helicopter-borne stinger-mounted airborne magnetic survey undertaken by Fugro Airborne Surveys Corp on behalf of Hi Ho Silver Resources. The survey totalled 293 line kilometres, including 22.5 line-km of tie lines.
In 2012, the green-blue stained areas sighted in 2010 were visited by Hi Ho Silver Resources. It was believed that previous operators had likely not seen the stained areas because they would probably have been snow-covered. A quartz monzonite porphyry dyke associated with the green-blue stained area is highly anomalous in molybdenum as well as anomalous in silver, tungsten, rhenium and palladium. It is located 500 metres north-northeast of and along strike from the previously-known Mount Thomlinson Mo-Cu deposit and suggests that the Mount Thomlinson mineralization might extend into the area.