The M2 (Gumbo and JC zones) prospect is located 450 metres west of the Finn zone (Minfile 094E 171), approximately 4.5 kilometres north-northeast of Kadah Lake and 4.5 kilometres south of Oxide Peak.
The prospect consists of at least two zones, referred to as the Gumbo and JC zones. The area lies within the Omineca-Cassiar mountains at the southern end of the Toodoggone gold camp. The M2 prospect 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 Neogene sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins. Figure 4 from Assessment Report 30143 the JC zone being located approximately 1 kilometre southwest of the Finn zone (JD).
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. Takla volcanics have been intruded by the granodiorite to quartz monzonite Black Lake Suite of Early Jurassic age 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 M2 occurrence is underlain by a thick succession of Lower Jurassic volcanics of the Toodoggone Formation. The sequence has been subdivided into two members that are separated by a low-angle thrust (?) fault. The upper McClair Member consists of heterogeneous, lapilli to block tuff, andesitic flows and numerous cogenetic dikes and subvolcanic plugs; minor mudstone and conglomerate (Bulletin 86). The underlying Metsantan Member consists of latite flows with lenses of lapilli tuff and lahar; minor volcanic sandstone and conglomerate (Bulletin 86). Both members are dominated by flows and flow breccias around the M2 prospect (Assessment report 18015). This sequence is cut by a series of steeply dipping diabasic and rhyolitic dikes.
Alteration on the M2 is structurally controlled and ranges from weak propylitic to intense silicic, argillic and phyllic. Propylitic alteration is the most widespread and important alteration type of the prospect, either hosting mineralized veins or forming haloes around more intensely altered and mineralized systems. Propylitic alteration consists of replacement of plagioclase phenocrysts by epidote or hematite and mafic phenocrysts by chlorite, epidote, actinolite, talc and disseminated calcite (Assessment Report 18015).
The Gumbo and JC zones are marked by extensive silicification and clay alteration along a low-angle thrust (?) fault that juxtaposes the McClair Member against the Metsantan Member, both of the Toodoggone Formation. The apparent vertical offset on this fault is 1215 metres (Assessment Report 18015). The JC zone, directly south of the Gumbo zone, is thought to be the southern displaced extension of the Gumbo zone, due to a steeply dipping, east-striking crossfault.
In all, the alteration zone hosting the Gumbo zone has a strike length of 800 metres and a maximum width of 5 metres. On surface, the Gumbo zone is composed mainly of yellow and beige clay (fault gouge) with angular to rounded fragments of argillic altered and silicified andesite. Post-alteration and mineralization motion along this fault is evidenced by re-brecciation of silicified layers. Moderate to well- developed propylitic alteration envelopes the fault zone. Silicification persists for several metres below the fault in the footwall. Propylitic alteration decreases with depth and is gradually replaced with hematite alteration of groundmass and phenocrysts.
Mineralization at the Gumbo and JC zones is concentrated in silicified and brecciated andesites. Chalcopyrite and minor galena, sphalerite and pyrite comprise mineralization contained in narrow quartz +/- carbonate veinlets in both the hangingwall and footwall rocks of the low-angle thrust (?) fault.
The Gumbo zone contains variable medium to high-grade gold and silver mineralization over 0.5 to 5.0 metres width and at least 400 metres length (Assessment Report 18015). Important gold values are concentrated in silicified portions of the footwall.
In 1979, chip sampling of trench 2A yielded 2.5 grams per tonne gold over 9.15 metres, including 3.8 grams per tonne gold over 3.05 metres, whereas a channel sample yielded 1.34 per cent lead, 0.14 per cent zinc, 26.3 grams per tonne silver and 23.1 grams per tonne gold over 0.15 metre (Assessment Report 8058). Sampling of trench no. 6, located approximately 150 metres to the south-southeast, yielded 5.5 grams per tonne silver over 34.3 metres, including 0.17 gram per tonne gold over 3.0 metres (Assessment Report 8058).
In 1981, re-sampling of drillcore from the 1974 drillhole MM-7 yielded several mineralized intersections including 1.74 grams per tonne gold over 2.0 metres (10.0 to 12.0 metres down hole), 0.33 gram per tonne gold and 0.20 per cent zinc over 14.8 metres (41.7 to 56.5 metres down hole), including 2.38 grams per tonne gold over 0.5 metre and 0.30 gram per tonne gold, 0.23 per cent lead and 0.35 per cent zinc over 9.1 metres (81.2 to 90.3 metres down hole; Assessment Report 9372).
Also at this time, a rock sample (18730) from a previous trench assayed 1.68 grams per tonne gold and 6.2 grams per tonne silver, whereas another sample (18723) from an area of intense pyrite-chlorite, located approximately 400 metres to the south-southeast of the trenches, yielded 20.2 grams per tonne silver (Assessment Report 9372). Later that year, two rock samples (71139 and 71140) from the area of the trenches yielded 1.13 and 3.36 grams per tonne gold with 254.8 and 115.9 grams per tonne silver, respectively (Assessment Report 9833).
In 1982, chip sampling of trench 1 yielded 6.18 grams per tonne gold and 15.9 grams per tonne silver over 25.0 metres, including 61.90 grams per tonne gold and 88.9 grams per tonne silver over 1.0 metre, whereas trench 2 yielded 15.25 grams per tonne gold and 67.8 grams per tonne silver over 5.0 metres, including 38.13 grams per tonne gold and 106.0 grams per tonne silver over 1.0 metre (Assessment Report 10739).
In 1983, samples of silicified material from the Gumbo zone yielded values of up to 70.2 grams per tonne gold and 185 grams per tonne silver, whereas chip sampling (J83P-3 and J83P-1) of trenches yielded 6 and 18 grams per tonne gold with 141 and 18 grams per tonne silver over 1.35 and 1.30 metres, respectively (Assessment Report 11843).
In 1984, diamond drilling on the Gumbo zone yielded up to 4.72 metres grading 44.82 grams per tonne gold and includes a 2.25 metre section of 99.1 grams per tonne gold in hole J84-01 and 4.74 grams per tonne gold over 2.23 metres, including 15.10 grams per tonne gold over 0.4 metre in hole J84-02, while a 1.5-metre channel sample from the JC zone assayed 1.60 grams per tonne gold and 8.5 grams per tonne silver (Assessment Report 18015).
In 1994, diamond drilling on the Gumbo zone was reported to have yielded generally disappointing results with intercepts of up to 9.36 grams per tonne gold and 408.0 grams per tonne silver over 1.00 metre in hole 94-02 (Assessment Report 23663).
In 2012, drillhole JD-12-013 on the Gumbo zone yielded intercepts of up to 1.21 grams per tonne gold and 4.9 grams per tonne silver over 11 metres (Assessment Report 33556).
Work History
The best results were obtained during a drill program conducted by Kidd Creek Mines Ltd. in 1984.
AGC Americas Gold Corporation and Antares Mining and Exploration Corp. drilled one drill hole on the JC zone in 1997. AGC acquired all the Toodoggone properties in July 1999. AGC is a subsidiary of Timebeat.com Enterprises Inc. Antares became Canesa Capital Corporation in September 1999. In 2011, Tower Resources optioned the JD property and the following year completed an 18 hole diamond drilling program, totalling nearly 3000 metres.
Recent work history in the Gumbo area includes drilling and soil sampling in 2012 aeromagnetic surveying in 2008. In 2012, drillhole D-12-013 was collared 200 metre southwest of the edge of Finn zone. The hole was designed to test the southwestern extent of Finn zone mineralization in an area with strong mineralization in historic trenches and drill holes (Gumbo/Gasp Zone), and where the Finn Zone should trace southwards due to topography and its shallow dip. The hole did intersect at suite of zones in the uppermost 50 metres.
The Gumbo and Gasp (094E 168) zones were grouped by Tower Resources in 2013 and reported to be located 250 metres southwest of the Finn zone. This zone consists of silicified and brecciated andesite cut by quartz and carbonate stringers and represents an extension of the Finn zone or part of the footwall.
See Finn (JD) for details of the JD property of which the Gumbo is part of.
