Kechika Trough Regional Exploration
Canada Zinc Metals owns 100% of a dominant land position within the southernmost portion of the Kechika Trough, a total of 78,526 hectares in 233 claims. These claims extend northwestward from the Akie property for a distance of 125 km and overlie areas of black shales and associated mineral occurrences of the highly prospective Upper Devonian Gunsteel formation. Some 55% of these claims are currently in good standing until 2013 and a further 32% to 2017.
In 2007, Canada Zinc Metals initiated a program of regional exploration, the work consisting of data acquisition and limited field activities. During the 2008 season, studies were focused on key properties in the southern half of its Kechika Trough holdings, namely Pie, Yuen, Cirque East and Mount Alcock, and comprised data compilation, prospecting, geologic mapping and silt and soil sampling. This work identified a number of new zinc-lead showings hosted by Gunsteel shale, ferricrete occurrences and geochemical anomalies, all of which require follow-up investigation. In addition, a geochemical data-base was established, incorporating 16,625 historical and 2,510 Canada Zinc Metals samples over a strike distance of approximately 70 km.
Mineralised prospects, showings and soil anomalies all trend in a NW-SE manner as determined by historical and current exploration. Exploration northwest of the Cirque deposit (owned jointly by Teck Resources and Korea Zinc) has significantly expanded the lateral extents of known anomalies. Known outcrops of Gunsteel shale (host to the Cirque and Cardiac Creek deposits) NW of the Yule property are promising in terms of mineralization as the timing, structural setting and stratigraphy, are interpreted to be very similar to the Cirque and Cardiac Creek deposits.
Geological Model
Synsedimentary mineralization in a deep water basinal setting is generally the accepted genetic model due to the finely layered and concordant nature of the sulphides. Syndiagentic depositional models, while valid in other regions, is yet to be convincingly documented within the Kechika Trough due to a paucity of heterogeneous veins, breccias or other non-concordant sulphide features – although recent drilling at the North Lead anomaly on the Akie property (see project description) has identified a number of discordant features (sulphides in veins and breccias) supporting a more dynamic setting. The presence of pyrobitumen at Cardiac Creek and elsewhere in the Kechika trough possibly indicates a distal Mississippi Valley Type (MVT) protolith.
The lack of associated deposit scale tectonic features within the Kechika Trough (unlike at Red Dog, Alaska or George Fisher, Australia) presents somewhat of an enigma – this despite the belief that regional, cross cutting major faults are a likely candidate for foci of hydrothermal cells.
With one exception, all discoveries in the Kechika Trough were the direct result of visual observations of prominent gossans/ferricrete seeps or as geochemical anomalies. Only the Cardiac Creek deposit was discovered using a combination of geology, detailed mapping, soil sampling and very limited geophysics. There has never been a comprehensive geophysical program in the district - despite the presence of a >50 million tonne deposit!
Given the favourable and consistency of the stratigraphic section hosting a mineralizing system that occurs over a 180 km strike and the presence of regular and generally persistent occurrences of stratiform base metal showings and deposits, Canada Zinc Metals believes that further discoveries are not only possible but are highly probable. The fact that the Cardiac Creek deposit occurs at the contact between the Gunsteel shale and Road River Group, provides additional, previously unrecognized, exploration targeting concepts. Key deposits in the region were historically thought to occur higher up in the Gunsteel shale as opposed to the base of the unit. There is also the possibility that mineralization exists well below the key Gunsteel formation as part of an extensive feeder zone – this may be present and represents another new exploration targeting concept.