Northern Crown sizes up asset — Prefeasibility study estimates resource for Guadalupe de los Reyes

In a prefeasibility study, Northern Crown Mines (NCW-T) estimates its Guadalupe de los Reyes project in western Mexico contains a total of 12.1 million tonnes grading 1.94 grams gold and 40.7 grams silver per tonne.

The project, which lies more than 100 km north of Mazatlan in Sinaloa state, comprises three deposits: Zapote-Tahonitas; Chiripa-San Miguel-Noche Buena; and the Guadalupe Mine zone.

The resource estimate was based on fire assays from 375 reverse-circulation drill holes. A cutoff of 0.5 gram gold per tonne was used for mineralization available for open-pit extraction, whereas a cutoff of 1-1.5 grams was used for the underground portion.

o Zapote-Tahonitas — The Zapote portion of this deposit has been defined by 197 holes, drilled at 25-metre centres over an area measuring 1,000 by 150 metres. The preliminary reserve estimate is 5.8 million tonnes grading 1.36 grams gold and 8.7 grams silver, which translates into a contained reserve of 255,000 oz. gold and 1.6 million oz. silver.

So far, only 33 holes have been drilled at the neighboring Tahonitas zone.

The reserve estimate there stands at 701,000 tonnes of 1.46 grams gold and 49.8 grams silver, equivalent to a contained reserve of 33,000 oz. gold and 1.1 million oz. silver.

Northern Crown envisages Zapote-Tahonitas as an open-pit/heap-leach operation, with higher-grade zones minable by underground methods.

o Chiripa-San Miguel-Noche Buena — The Chiripa-San Miguel zone has been defined by 33 holes along 1 km. The geology has been described as a steeply dipping vein-stockwork system that ranges from 3 to 20 metres in thickness.

The zone remains open beyond a depth of 100 metres, and resource estimates indicate an underground resource of 1.1 million tonnes grading 3.79 grams gold (136,000 contained ounces) and 91 grams silver (3.3 million contained ounces).

The 350-metre-long Noche Buena zone is potentially minable by open-pit methods. Reserve calculations based on 25 holes indicate a resource of 1.6 million tonnes grading 1.38 grams gold (59,000 contained ounces) and 24.5 grams silver (1.3 million contained ounces).

o Guadalupe Mine zone — This 2,500-metre deposit has been defined by 78 drill holes along a strike length of 1,000 metres. The 800-metre Central Laija portion is estimated to contain an open-pit and underground resource of 1.8 million tonnes grading 3.94 grams gold (225,000 contained ounces) and 134.6 grams silver (7.7 million contained ounces). The 200-metre-long West portion is amenable to open-pit mining and estimated to hold 1.1 million tonnes grading 1.4 grams gold (50,000 contained ounces) and 26.1 grams silver (945,000 contained oz.).

Northern Crown will continue drilling in 1998 in an attempt to define additional areas of known mineralization near surface and at depth.