The Marmot occurrence is located approximately 18 kilometres north-northwest of the Lawyers mine (094E 066), some 280 kilometres north of Smithers. It lies within the Omineca-Cassiar Mountains at the southern end of the Toodoggone gold camp. The 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 Marmot showing is underlain by intermediate porphyritic rocks of the Toodoggone Formation. These include feldspar hornblende crystal and crystal-lapilli tuffs, and tuff breccias, a thin ash-fall tuff and lesser dacite porphyry flows. Cutting this sequence is a small diorite plug, diorite porphyry, and commonly narrow and scattered basalt and andesite dikes. The volcanic sequence appears to dip moderately to the northeast. Observed faults have northwest and east-southeast to southeast strikes. The most important structural feature is a vertical shear and fracture zone that extends northwestward from McClair Creek to Moosehorn Creek.
Initial property exploration, in the area of the Scree 3 occurrence, was focused on lead and zinc sulphides in quartz veins about 1.15 kilometres to the west. Early geochemical surveys outlined an area of about 1500 metres long with anomalous, silver, lead, zinc and copper in soils. Follow up geochemistry, geophysics and geology revealed local mineralization, confirming previous geochemical anomalies.
Mineralization consists of a vein-fault system hosting sphalerite and galena mineralization over 5 to 15 centimetre widths, located within a broad gold soil anomaly.
In 1985, assay values up to 7.0 grams per tonne gold, 1841.0 grams per tonne silver, 3.92 per cent zinc, 2.90 per cent lead and 0.020 per cent copper were obtained from grab samples (Assessment Report 13961).
Another zone of similar mineralization is reported to be exposed in the bed of a small creek, located approximately 500 metres to the west-northwest, and comprises several quartz veins, 2 to 10 centimetres in width, hosting galena, sphalerite and lesser chalcopyrite. Also at this location, a 5-centimetre-wide band of massive sulphides, dipping 30 degrees to the north and associated with disseminated galena, sphalerite and chalcopyrite, is reported.
In 1979, sampling of trench 44E-25N, located on the above zone, yielded 0.24 per cent zinc over 15.25 metres with values of up to 0.17 gram per tonne gold, 1.0 gram per tonne silver, 0.28 per cent zinc and 0.11 per cent lead over 3.05 metres (Assessment Report 8058).
In 1980, a rock sample (18697) from the creek zone assayed 22.3 grams per tonne silver (Assessment Report 9269).
In 1981, rock samples from the creek area yielded values up to 0.643 per cent lead, 0.109 per cent zinc, 4.1 grams per tonne silver and 0.190 gram per tonne gold (Assessment Report 9832).
A third zone of mineralization, located on a ridge approximately 750 metres to the north-northwest, comprises an area hosting quartz stringers near a basaltic dike.
In 1981, two rock samples (DP-294 and -298) yielded 0.345 and 0.335 gram per tonne gold with 24.0 and 8.7 grams per tonne silver, respectively (Assessment Report 9832).
In 1985, a rock sample (G-61) of quartz-pyrite veining from the ridge to the north-northwest yielded 0.46 gram per tonne gold and 38 grams per tonne silver (Assessment Report 13961).
Work History
The Marmot zone, 2.5 kilometres east of the Moose zone (094E 031) was initially reflected by a broad gold in soil anomaly. Refer to the Porphyry Pearl (094E 084) for information on the Porphyry Pearl property of Starfire Mineral which encompassed the Marmot in the 2000s and 2010s though no direct work was done on the zone to 2014 by Starfire.
