The Swan occurrence is located on the Tanzilla Plateau in northern British Columbia, about 12 kilometres east of Kedahda Lake and 120 kilometres north-northwest of the community of Dease Lake.
The showing is underlain by granite, quartz feldspar porphyry, alaskite, and diorite of the Late Cretaceous Glundebery batholith. Molybdenite occurs as coarse rosettes in 2 to 10 centimetre-wide quartz veins and as fine-grained disseminations in brecciated quartz veins up to 35 centimetres wide. The breccia veins strike northeast. Other quartz-molybdenite and quartz-molybdenite-arsenopyrite-pyrite-magnetite veinlets occur in a northwest trending mineralized zone. Chlorite occurs along fractures. Felsic and mafic dikes cut the intrusion.
The primary host for the molybdenum mineralization is a variable coarse to fine grained un-crowded quartz feldspar monzonite porphyry grading to a fine grained equigranular monzonite, intruded locally by southwest trending fine grained felsite dikes.
In 2008, a drilling program tested a portion of a large, erratically distributed low grade molybdenum mineralized zone. The zone is 400 metres wide and 900 metres long (north-northwest trending) and open in both directions along strike. Results from the drilling indicated that mineralization is now considered as limited to northerly trending corridors with waste rock in between. The best values encountered appear to be at the southeast end of the system where drillhole Swan 04 08 intersected a 73-metre section averaging 0.06 per cent molybdenum (from 9 to 82 metres). Drillhole Swan 08 08 intersected two sections: 14 metres averaging 0.07 per cent molybdenum (20.7 to 34.7 metres) and a 19-metre section averaging 0.06 per cent molybdenum (from 51.7 to 70.7 metres) (Assessment Report 30191). Molybdenite mineralization is preferentially located in sheeted quartz veins rather than in stockworks or fracture zones. Anomalous tungsten values generally coincide with zones of higher molybdenum, but grades are generally less than 300 parts per million and have an erratic distribution. The area of the system tested appears to be structurally controlled and associated with possible imbricate, 350-degree trending fault zone systems rather than a continuously mineralized stockwork system or a quartz-flooded system within the 2100 metre northwest trending length of the molybdenite mineralized zone as seen on the surface.
In the late 1960s, the initial discovery of molybdenum mineralization on the Swan property was made during the course of a regional prospecting program carried out by Union Miniere Mining Corp. In 1970, an area of roughly 20 square kilometres was staked surrounding the discovery showings and soil geochemical and ground geophysical surveys were completed in 1971. In 1972, Union Miniere completed an induced polarization and resistivity survey and drilled at least one core hole; there is no record of the results of this drilling. In September 1973, N.C. Aspinall, L. Schoen and R. Smith of Atlin, briefly made a helicopter-supported reconnaissance of the property for Canadian Johns-Manville Company Ltd. Soil and silt samples were collected which showed anomalous molybdenum. Since the area was already claimed by others, no follow up was made. The initial claims lapsed in 1974(?) and the property was re-staked by Amax Potash Limited in 1976. During that field season, an exploration program consisting of line cutting (27.2 kilometres), geological mapping, geochemical soil sampling (350 samples), as well as ground magnetic (27.2 kilometres) and induced polarization (19.2 kilometres) surveys were completed. In 1978, a joint provincial/federal government geochemical stream sediment and water survey was completed for the entire Jennings River (104O) map area and the data was interpreted and published as Open File RGS 52 in July, 2000.
In January 2005, the property was re-staked by J.M. Dawson and N.C. Aspinall. A brief survey was made by Aspinall in June 2005 as a geochemical orientation reconnaissance. Along with a number of other prospects, staked as after RGS geochemical anomalies, the property was incorporated into the Rossing Joint Venture in February, 2007. The Rossing Joint Venture concluded an option agreement with Hastings Resources Corp. in April, 2007. In June 2007, Aspinall was accompanied by A. Doherty of Aurum Consultants of Whitehorse and collected ten rock samples from the molybdenite zone. Between 3rd August and 28th August 2007, a total of 463 geochemical samples (393 soils and 70 silts) were collected. During 14 days of September 2007, Aspinall prospected and collected rock samples for analysis from the molybdenite zone on upper Tahoots Creek, and found that there are at least two north-south boulder trains of mineralized molybdenite rocks as well as two molybdenite mineralized outcrop zones, and collectively traced over a northwest-trend of 2100 metres. In 2008, under an option agreement between the Rossing Joint Venture and Hastings Resources Corp., 13 drillholes totalling 991.5 metres were completed. During the early exploration work the company noted very anomalous values in molybdenum, tungsten, tantalum, niobium and REEs (rare earth elements) in various phases of the Glundebery batholith. Subsequently, a large block of ground was staked and detailed geochemical soil and silt sampling as well as prospecting and reconnaissance geological mapping were completed over selected areas. This work has outlined a number of molybdenum, tungsten-copper-molybdenum and tungsten-copper-silver anomalies which vary in surface area from 0.2 to more than 3.5 square kilometres and which in several areas remain open.
