Aquila Boosts Resource at Back Forty

The Back Forty massive sulphide deposit in Menominee Cty., in the Upper Peninsula of Michigan, has more than double the previously estimated resource, according to a newly filed calculation.

Owner Aquila Resources (AQA-V, AQARF-O) engaged consulting firm Datamine to calculate the new resource, which is based on about a year and a half of new drilling and incorporates mineralization on contiguous properties that had not been acquired at the time of the last calculation, in August 2005. Datamine put the measured and indicated resource at 6.6 million tonnes with grades of 5.32% zinc, 0.52% copper, 0.21% lead, 28.8 grams silver and 2.3 grams gold per tonne.

That splits out into a 4.1-million-tonne resource on the South Limb zone, at 6.58% zinc, 0.25% copper, 0.16% lead, 18.6 grams silver and 1.8 grams gold per tonne, and about 1 million tonnes on each of two other zones: the East Zone, with 5.64% zinc, 0.4% copper, 0.07% lead, 17.5 grams silver and 2.8 grams gold; and the lower-grade Pinwheel zone, with 1.02% zinc, 1.75% copper, 0.16% lead, 57 grams silver and 1.8 grams gold.

Another 269,000 tonnes grading 7% zinc, 1.74% lead, 0.06% copper, 57 grams silver and 1.4 grams gold per tonne is in the Tuff Zone, and about 232,000 tonnes of mainly gold and silver mineralization is in gossan material at the top of the Pinwheel and East Zones.

There is an additional inferred resource of about 1.8 million tonnes, with 1.2 million tonnes in stringer sulphide material that grades 0.58% zinc, 0.19% copper, 0.09% lead, 16.7 grams silver and 3.2 grams gold per tonne, and almost all the rest — 586,000 tonnes — in the Tuff Zone, which grades an average 6.62% zinc, 1.74% lead, 0.06% copper, 63 grams silver and 1.9 grams gold per tonne.

Aquila believes the East Zone is essentially drilled off, but all other zones are open in one or more directions. Aquila plans to test areas pointed out by down-hole electromagnetic surveys in further drilling, and is adding another drill.

The recently discovered 90 Gold Zone, and gold mineralization near the contacts of late quartz-feldspar porphyry dykes, are not part of the resource estimate. There is also potential for additional resources in the Deep Zone down-plunge from the known resource.

The resource calculation, based on 151 drill holes for a total of 35,000 metres of core, does not use a cutoff grade, but bounds the deposit based on geological criteria.

The calculation also fulfills the key requirement for Aquila to move its listing to the Toronto Stock Exchange from the TSX Venture Exchange. Aquila received conditional approval for the graduation on April 23.