The Gravy showing is 1.75 kilometres south of Toodoggone Lake and 2.75 kilometres east-northeast of the Mount Graves prospect (094E 087) (Assessment Report 17226). Smithers is 290 kilometres to the south.
The Gravy showing is situated within a Mesozoic volcanic arc assemblage which lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Tertiary sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.
Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Takla Group andesite flows and pyroclastic rocks. These Takla rocks have been intruded by plutons and other bodies of the mainly granodiorite to quartz monzonite Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against Lower Jurassic calcalkaline volcanics of the Toodoggone Formation, Hazelton Group.
The dominant structures in the area are steeply dipping faults which define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
The Gravy showing lies within a granodiorite stock of the Omineca intrusions near its contact with undivided volcanics of the Hazelton Group. Hazelton volcanics consist of grey, green and purple andesitic flows and pyroclastics of the Hazelton Group. Bedding strikes northwest and dips moderately to the northeast. Numerous pink feldspar porphyry dikes and sills are associated with the volcanics. Numerous other small granodiorite stocks and plugs crop out in the area.
Abundant disseminated pyrite occurs in contact areas between volcanics and intrusive rocks. These are evident as prominent gossans, some of which also contain quartz veins and/or silica veins and breccias.
At the Gravy showing, quartz breccia hosts galena, sphalerite and chalcopyrite with associated malachite. The zone strikes 330 degrees, is approximately 5 metres wide and exposed for 20 metres along strike. The breccia material is composed of diorite cemented by quartz. The system contains quartz veins up to 12 centimetres wide but the stringers average 1 to 2 centimetres.
Of 5 rock samples collected from the showing, 3 yielded significantly anomalous precious and base metals. Sample MG-87-5 analysed 0.78 gram per tonne gold, 37.5 grams per tonne silver, 0.28 per cent copper, 1.34 per cent lead and 0.74 per cent zinc. Similarly, sample MG-87-7 analysed 0.63 gram per tonne gold, 13.7 grams per tonne silver, 0.41 per cent copper, 2.51 per cent lead and 0.22 per cent zinc (Assessment Report 17226).
The Quartz Filled Breccia zone plots within a few hundred meters of the Gravy showing (to the southeast) and may in fact be the same showing or possibly an extension (Assessment Report 24993). In 1996, Vetta Ventures traced the Quartz Filled Breccia zone, along a strike of 330 degrees for 300 metres, with a total exposure of 64 metres. Mineralization consists of disseminated pyrite, chalcopyrite, sphalerite, copper staining and fine-grained galena in white to creamy massive quartz hosted by brecciated altered quartz monzonite to granodiorite of Omineca intrusives.
The zone is exposed on and off in five different locations along its strike. At Location A, the Quartz Filled Breccia zone is exposed for 35 metres; then it goes under overburden for 25 metres. At this location, the zone strikes 330 degrees/70 degrees southwest dip. At Location B, the zone is exposed for 3 metres and strikes 315 degrees/79 degrees southwest dip. At Location C and D, the zone was located again at 46 metres and 57 metres at a bearing of 135 degrees from Location B. The last 33 metres of exposure of the zone was located at 204 metres at a bearing of 142 degrees from Location D.
Mineralization within the Quartz Filled Breccia zone is restricted to the far northwest exposure (Location A) where propylitic alteration is noticeable through the host rock. Mafic minerals are altered to chlorite and epidote. Plagioclase crystals are replaced and zoned with epidote and chlorite. Common textures include drusy cavities and comb quartz.
Eleven rock chip samples were collected across the zone over a 35 metre exposure in Location A. Samples averaged 0.88 gram per tonne gold, 27.9 grams per tonne silver, 0.2 per cent copper, 0.13 per cent lead and 0.75 per cent zinc over an average width of 42 centimetre (Assessment Report 24993).
In 2003, a sample (132727) from a shear zone in granodiorite from the area of the Gravy occurrence yielded 3.2 grams per tonne silver and 0.296 per cent lead (Assessment Report 27441). The following year, two float samples (185997 and 185998) of quartz-calcite veining with malachite and chalcopyrite, taken downslope of the occurrence, yielded values up to 0.178 gram per tonne gold, 2.9 grams per tonne silver, 0.180 per cent copper and greater than 1.00 per cent zinc (Assessment Report 27734).
Work History
In 1980, Du Pont of Canada Exploration Limited staked the TO claim (094E 212). Ten stream sediment samples and 3 rock samples were collected.
In 1989 and 1981 work performed by Serem Ltd on their Duke 1 and 2 claim consisted of detailed silt sampling of streams draining the claims, 2 soil contour lines, 6 soil lines on a loose grid, and prospecting and mapping of the exposed areas (094E 218) (Assessment Report 9502). A total of 114 soil and silt samples and 15 rock samples were collected and analysed. The Duke 1 and 2 covered the area the Gravy (094E 205), Grav East) (094E 206), TO 2 (094E 212) and Duke (094E 218) occurrences.
The Mount Graves property was optioned by Great Western Petroleum Corp. in 1981 and a geological-geochemical field program was conducted on the property between 1981-1983, which resulted in the discovery of the GWP mineral showing which returned values as high as 1.1 per cent gold and 7500 grams per tonne silver in rock samples (Assessment Report 10050).
Douglas Forster (1984) completed a Master of Science thesis on the southern Toodoggone River area with a comparative economic geology analysis of eight prospects including Mount Graves. Using data from fluid inclusion analysis of mineralized rock from the Mount Graves property, Forster proposed a regional epithermal model that places Mount Graves at a depth favourable for hosting mixed precious and base metal deposition.
In 1984, the area of the gossan zone near Vole Peak was tested by Newmont Exploration of Canada for possible links of the gossan zone to the GWP Zone (Assessment Report 13458).
Geostar Mining Corp conducted assessment work in 1985 and in 1986, Yeager and Ikona resampled the GWP Zone. Rock grab samples yielded gold values up to 5.82 grams per tonne and silver values up to 5115.37 (Assessment Report 14824). Also investigated was the Yellow Rose zone, a gossan associated with argillic alteration and quartz veining, 550 metres south of the GWP zone. Thirty metres of trenching revealed sparse quartz veining with gold values up to 10.49 grams per tonne gold in a 5 centimetre wide quartz vein (Assessment Report 14824). Lead and zinc values over 1 per cent were also noted.
Work performed Blue Emerald during the 1987 program confirmed the GWP zone as the most promising prospect on the Mount Graves property. Results of trenching and mapping indicate probable extensions to the southwest and northeast. Rock chip sampling on the GWP zone yielded values up to 3 grams per tonne gold, 503 grams per tonne silver, 1.45 per cent lead and 3.38 per cent zinc (Assessment Report 17326). Additional trenching and rock sampling was done on the Yellow Rose zone with indications that similar mineralization may occur on a southeasterly extension.
The Gravy claims were previously held by Hemlo Explorations Ltd. Work on the property in 1985 consisted of grid and contour soil sampling in selected areas. The exploration program on the Gravy II and IV claims in 1985 consisted of wide-spaced contour soil sampling and grid soil sampling in two areas at the southwest corner of the property (Assessment Report 14436). Work in 1987 for Mt. Graves Explorations Inc included reconnaissance geological mapping, stream and grid soil sampling. This work resulted in the discovery of anomalous precious metal values in rocks, silts and soils (Assessment Report 17226).
The 1989 sampling program of Blue Emerald Resources on the Graves 1-2 was concentrated primarily in the areas of the Lake Fault Zone, Yellow Rose Zone, GWP Zone, East Ridge Zone, and Vole Peak (Assessment Report 19767). Work consisted of contour talus-soil sampling, grid soil sampling, prospecting, mapping, and trenching. A total of 199 soil, 58 rock, and 2 heavy mineral samples were collected. The Gravy claims covered the To (094E 212), Gravy (094E 205) and Gravy East (094E 206).
In 1996, Vetta Ventures Corp conducted exploration work on their Jessye 1 to 3 claims that consisted of geological mapping rock sampling, grid work, soil and stream sediment sampling, and Mag-VLF geophysical surveys (Assessment Report 24993). A total of 74 rock and 344 soil samples and 21 stream sediment samples were collected from the property during the 1996 survey. Geological mapping was performed at scale 1:5,000 over the property. VLF-EM and magnetometer geophysical survey was carried out over the main grid area. Readings were taken at all stations at 12.5 metre spacing. Three promising mineralized areas, the Quartz-filled Breccia Zone, the GWP zone and the Yellow-Rose zone, were located and sampled during the 1996 field work program. The Quartz-filled Breccia zone plots out in the vicinity of the Gravy occurrences (094E 205) which has the same strike and description.
In 2003, Stealth Minerals Ltd staked four claim unit (80 units) Sam claims. The Sam claims covered the Graves (GWP) (094E 087), Yellow Rose (094E 203), Gravy (094E 205), Gravy East) (094E 206), TO 2 (094E 212), Duke (094E 218). Stealth minerals undertook a 10 man-day helicopter supported reconnaissance and point specific prospecting and geological evaluation program. A total of 18 rock samples were taken. As part of the regional Government-Private Partnership Toodoggone Initiative, the claims were covered by part of the Fugro operated, Geological Survey of Canada supervised, helicopter airborne magnetic and radiometric survey. The survey recorded 2 magnetic parameters and eight gamma-ray spectrometer parameters flown at a line spacing of 400 metres and a sensor height of 60 metres during 2003. The survey indicated that the claims are underlain by rocks and alteration permissive to host precious metal deposits. A 1.3 by 1.0 kilometre ThK ratio low occurs within the Sam 3 claim coincident to a potassium high and adjacent to a total field magnetic high. Rock sampling occurred in the area of the Gravy (094E 205) and Gravy East (094E 206).
In 2004, Stealth Minerals conducted geological mapping on the Sam claims at 1:10,000. In addition, a total of 11 surface rock samples were taken as float or outcrop samples for analysis. Alteration identification using PIMA spectroscopy was completed on 19 rock samples.
