The Ptarmigan occurrence is underlain from west to east by Permian limestones, conformably overlain by Middle Triassic cherty siltstones and shale, in turn overlain by pervasively altered Upper Triassic Stuhini Group massive andesite and flow breccia which are intruded by monzonite to monzodiorite along a northwest trending faulted(?) contact. A Jurassic polymictic boulder conglomerate containing volcanic, sedimentary, granitic and rhyolite clasts outcrops in uncertain stratigraphic position nearby. Northeast striking faults and shear zones appear to crosscut older northwest trending structures. Both structures contain mineralization, the younger are sulphide-rich.
The Ptarmigan zone is a circular quartz-sericite-pyrite alteration zone, 50 metres in diameter, localized at the intersection of a northeast striking fault (Ptarmigan shear) and a northwest trending fault separating Triassic-Jurassic volcanic and sedimentary strata and Middle Triassic Hickman batholith monzonite. The monzonite is brecciated into angular blocks as large as 0.5 by 1.5 metres which are locally aligned and commonly dip southwestward into the zone. Within the Ptarmigan zone the monzonite is pervasively sericitized and bleached. Iron carbonate and pyrite occur as stockwork veinlets and matrix replacements. Away from the Ptarmigan zone the monzonite is coarse-grained, massive and moderately chloritized. Adjacent to this intrusive breccia is an equally altered polymictic matrix-supported fault breccia containing well-rounded clasts of augite porphyry, monzonite, chert and feldspar porphyry. Angular blocks of altered monzonite, some veined by iron carbonate and pyrite are also present. The matrix is sericitized and locally completely replaced by pyrite. Clast lithologies are identical with those in the polymictic conglomerate overlying volcanics to the east.
Precious metal mineralization occupies narrow and widely spaced fractures, veinlets and stockworks which crosscut the pyrite alteration zone. Vein mineralogy comprises disseminations of pyrite, galena, sphalerite, chalcopyrite, tetrahedrite, minor arsenopyrite and electrum in a quartz-carbonate gangue. Mineralization is silver-rich with silver:gold ratios averaging 80:1; the silver mineral has not been identified.
During 1990, the Ptarmigan Zone structure was the target of six diamond drill holes, totalling 1054.85 metres. Drilling confirmed that the best mineralization is associated with silicification containing base metal sulphides within strongly sericitized heterolithic breccia. The sericitization envelope is limited to the north, but still remains open to the south beneath the Ptarmigan Glacier. Northeast trending dilational features related to the Ptarmigan Fault appear to exert strong structural control over mineralization and, consequently, mineralized zones are limited in extent. In 1991, Gigi Resources reported that zone had been well tested and did not demonstrate sufficient grade, extent and continuity to warrant further exploration (Assessment Report 21061).
WORK HISTORY
In 1964 Silver Standard Mines staked the BIK 87-116 claims over the region now covered by the Trophy 1-4 claims following rumours of spectacular copper values being received in the Galore Creek deposit ten kilometers to the southwest. Lead-zinc mineralization (Ptarmigan showing) was discovered on the BIK claims in a north facing cirque. Silver Standard Mines was disappointed at not discovering a large copper ore body, so no further exploration was undertaken, and the claims were allowed to lapse in the late 1960s.
The Trophy Gold property, consisting of 769 units, was staked on behalf of Continental Gold Corp in 1987, 1988 and 1990 to cover favourable lithology and known mineral occurrences. Several base metal occurrences were investigated on the Trophy Gold property during the 1960s, with exploration focusing on its western edge. Field work on the Trophy claims during 1987 identified three major northeast trending, precious metal-bearing shear structures.
Extensive work was carried out by Continental Gold in 1988 when the drilling program successfully tested three gold zones (Ptarmigan, Eagle and Hummingbird. A total of 2834 metres were drilled in 16 holes. During 1988, a total of 1113 rocks and 181 soils were collected. The 1988 regional program located numerous areas of significant precious and base metal mineralization, 13 of which are considered to warrant immediate follow-up work (Assessment Report 18555).
In 1989 Gigi Resources Ltd completed work including 2,834 metres of diamond drilling on three showings. During the course of the 1989 program, 110 stream sediment samples, 400 contour soil samples and 415 rock samples were taken. An airborne geophysical survey was also conducted. Reconnaissance exploration, consisting of geological mapping, prospecting and geochemical sampling, was carried out over the property. During the course of this program, 110 stream sediment samples, 400 contour soil samples and 415 rock samples were taken (Assessment Report 19783).
1990, Gigi Resources Ltd. carried out a comprehensive exploration program on the Trophy Gold project, consisting of geological mapping, prospecting, geochemical sampling, ground geophysics, trenching and diamond drilling (Assessment Report 21061). This program was designed to define the extent, grade, and continuity of the Ptarmigan Zone, evaluate all known mineral occurrences and investigate the significance of the soil and airborne geophysical anomalies revealed by the 1989 program. During the course of this program, 80 stream sediment samples, 1890 soil samples, 618 reconnaissance rock samples, and 1884.9 metres in 10 holes were drilled. The Sapo Grid was established on the Glacier 6 claim to search for possible extensions of the Sapo and Mono veins (two new discoveries). The Galore geochemical/geophysical grid was established. Six trenches were blasted on the Sapo vein and on the Galore grid. Six diamond drill holes, totalling 1054.9 metres, tested the Ptarmigan Zone perpendicular to its controlling structure. On the Galore Grid, four more holes totalling 829.95 metres, were targeted at geological, geophysical, and soil geochemical anomalies. On the Trophy Gold property, numerous occurrences of porphyry-style mineralization, breccia-hosted mineralization, auriferous and/or argentiferous base metal veins, and skarns. It was reported that all known occurrences were thoroughly evaluated in 1990 and are described in Assessment Report 21061), some of which have been newly documented in MINFILE in 2013.
