Work History

The porphyry occurrence was first recognized in late 1969 by several exploration groups while most of it lay within the large claim block surrounding the Mt Nansen vein property. Part of the eastern side was originally staked as Yu cl 1-32 (73506) in May 1958 by Silver Standard Mines Ltd., which added Me cl 1-16 (73722) in July 1958 and carried out geological mapping and EM surveying in 1958-1959 and later carried out geochemical sampling and hand trenching.

During 1970, the Swiss interests controlling Mt Nansen Mines Ltd. explored the porphyry potential with stream sediment and soil geochemical sampling and airborne magnetometer, EM and K40 surveying. The portion of the claims beyond the mill site and developed vein systems were optioned from 1971-1975 by Area Exploration Company, a Cyprus Exploration Corporation Ltd. subsidiary, which carried out soil sampling, IP, magnetometer and EM surveying and drilled 11 percussion and diamond drill holes (1,770 m) in 1971; 12 holes (2,129 m) in 1972; and 3 holes (approximately 600 m) in 1973. Getty Mines Ltd participated in part of the 1972 program.

The western side was re-staked as Sen cl 1-8 (YA23985) in March 1979 by Cominco Ltd., which carried out geological mapping, prospecting and geochemical rock and soil sampling in 1979-1981. Mt Nansen Mines Ltd. transferred its interest to BYG Natural Resources Inc. in 1984. Chevron Canada Resources Ltd. optioned the BYG property in June 1985 and re-staked the west side of the occurrence as TBR cl 1-8 (YA86690) in May 1985 and EEK cl 1-18 (YA87210) to the east in June 1985.

G. Dickson re-staked the areas southwest of the occurrence as Bull cl 1-8 (YA81420) in February 1984; northeast of the occurrence as Wedge cl 1-15 (YA82167) in May 1984; and north of the occurrence as Etzel cl 1-50 (YA86336) in November 1984. Dickson carried out VLF-EM surveying and bulldozer trenching in 1985. Pearl Resources Ltd. briefly optioned the claims in 1986 and carried out geological mapping and geochemical sampling later in the year.

In 1987, the property was optioned to Aurchem Exploration Ltd., which carried out bulldozer trenching in 1987, geochemical sampling in 1988 and trenching, geological mapping, soil geochemical sampling and geophysical surveying in 1991 on claims surrounding the occurrence. The Wedge, Etzel, Bull, etc. claims were transferred to Dickson's widow, J. Dickson, in July 1993 and a program of trenching was carried out on the claims in November of that year.

In March 1995 the Wedge, Etzel and Bull claims were transferred to Aurchem Exploration Ltd. and combined with the company's other claim holdings in the area, which collectively became known as the Discovery Creek project (MINFILE occurrences 115I 068, 093, 096 and 117).

In July 1996, BYG Natural Resources Inc. signed a letter of intent to explore Aurchem's claims in the Mount Nansen area. Subsequently in September 1997, BYG entered into an agreement with Trumpeter Yukon Gold Inc. (a wholly owned subsidiary of BYG) whereby Trumpeter would be entitled to earn a 60% interest in the Aurchem claims by assuming a portion of the financial obligations outlined in the original agreement. As of December 1997, BYG and Trumpeter had not completed the terms outlined in the original letter of intent and negotiated a restructuring of the terms with Aurchem. In February 1999, BYG announced plans to temporarily shut down the Mount Nansen Mine. In March 1999, BYG was placed in receivership and the Nansen mine became a Type II Minesite.

The Wedge, Etzel and Bull claims reverted to Aurchem after the federal government took over maintenance of the adjoining Mount Nansen mine site in July 1999. In 2003 Aurchem performed geological mapping and sampling over the Cyprus occurrence.

In 2009, 101073531 Saskatchewan Corp. flew a regional airborne and magnetic survey that included the Cyprus occurrence. In 2011, Ansell Capital Corp optioned the Discovery Creek property, including the Cyprus occurrence, from Aurchem Exploration. Ansell Capital carried out bedrock mapping as well as rock and soil geochemistry in 2011.

Regional & Property Geology

The occurrence is located in the Dawson Range within Yukon-Tanana Terrane (YTT). The rocks of the YTT in this region consist of Early Mississipian metamorphic rocks separated into meta-sedimentary and meta-igneous suites (Stroshein, 1998). The meta-sedimentary suite consists of micaceous quartz-feldspar gneiss, schist and quartzite of the Nasina Assemblage. The meta-igneous package is comprised of biotite-hornblende feldspar gneiss and coarse-grained granodiorite orthogneiss with lesser amphibolite.

Four rock types dominate the geology surrounding the occurrence and are comprised of:
1. Paleozoic metamorphic Yukon-Tanana gneiss, quartzite, and amphibolite to the south;
2. Triassic to Jurassic metamorphosed alkali-feldspar-rich plutonic suites;
3. Mid-Cretaceous Mount Nansen Suite andesite, felsic lapilli tuffs, basaltic to latite volcanic rocks; and quartz feldspar porphyry, dacite, latite, and quartz monzonite porphyritic hypabyssal rocks; and
4. Mid-Cretaceous Whitehorse granodiorite.

The Cyprus occurrence is associated with a complex of subvolcanic plugs and dykes of rhyodacite porphyry and quartz-feldspar porphyry and andesitic rocks of the Late Cretaceous to Paleocene aged Mount Nansen volcanic suite which have intruded the granodiorite of the mid Cretaceous Dawson Range Plutonic Suite. The porphyry complex forms a northwesterly trending zone about 3.2 km long and 1.6 km wide. Two subcircular breccia pipes with a quartz-tourmaline matrix have a maximum diameter of 150 m on surface. Similar breccias found at depth have a matrix of quartz only. Hart and Langdon (1998) describe this occurrence as being the central porphyry zone of the Mount Nansen porphyry complex. The quartz-tourmaline zone is surrounded by successive phyllic, argillic and propylitic alteration zones.

Mineralization & Results

Pyrite, chalcopyrite and molybdenite occur as disseminations and in quartz veinlets and are most concentrated within the phyllic phase of a concentric alteration zone peripheral to breccia bodies associated with the Late Cretaceous plugs and dykes. Minor amounts of galena and sphalerite also occur in veinlets within the porphyry complex.

Leaching extends to depths of up to 60 m and has resulted in a weak supergene zone 0 to 90 m thick, in which chalcocite coats pyrite and, to a lesser extent, chalcopyrite. Grades vary considerably with the best values in the range of 0.5 to 0.6% copper and 0.06% molybdenum disulphide (MoS₂), associated with fractured zones where supergene chalcocite is well developed. The average hypogene grade is about 0.1 to 0.15% copper and 0.01% molybdenum disulphide. Average copper grades appear to be twice as high in the supergene zone.

The Cominco work performed between 1979 and 1981 was directed toward the tin potential of the breccia. Grid and soil sampling located weak molybdenum and tungsten response, but no tin. Chevron's trenches returned high gold backgrounds (up to 350 ppb) but no economically significant intersections. Welcome North's work showed that arsenopyrite and pyrite-bearing quartz veins occur in sericitized and argillically altered northwest-trending shear zones in the granodiorite. Specimens from the veins assayed up to 0.99 g/t gold.

Beginning in 2001 Aurchem Exploration began re-examining historic exploration data in order to create new exploration targets. In 2001, the company's efforts identified a 40 m wide silicified alteration system exposed in an outcrop of brecciated feldspar porphyry on Wedge cl 12 in the vicinity of a grab sample that had reportedly returned 270 ppb gold. A zone of pyritized phyllic alteration in the porphyry was discovered flanking the zone of silicification. Sampling of both zones returned weakly anomalous gold and silver values, ranging from 10 to 45 ppb gold with 0.4 to 1.6 ppm silver in the silicified zone and 10 to 110 ppb gold with 0.2 to 1.6 ppm silver in the flanking pyritized phyllic alteration zone.

Soil sampling in 2003 returned copper values up to 415 ppm and molybdenum values up to 204 ppm. Follow-up rock sampling returned up to 217 ppm copper and 1,015 ppm molybdenum.