Resource up at Young-Davidson (January 01, 2007)

Resources at the Young-Davidson gold project near Matachewan, Ont., have grown substantially in a new estimate commissioned by Northgate Minerals (NGX-T, NXG-X).

The new calculation, done by consulting firm Scott Wilson Roscoe Postle, considered three underground zones, Lucky, Lower Young Davidson, and Lower Boundary. It puts total measured and indicated resources underground at 5.2 million tonnes grading 3.6 grams gold per tonne.

A 2004 estimate by Micon International estimated 6.8 million tonnes grading 2.1 grams per tonne in a proposed open pit, which does not overlap with the new estimate. That tonnage had been classified as measured and indicated, and there was an additional 330,000 tonnes grading 1.3 grams per tonne inferred.

In the three zones considered by the new estimate, inferred resources amount to 4.7 million tonnes at 3.7 grams per tonne. Micon had earlier put an inferred estimate of 3.9 million tonnes grading 4 grams on a different zone, the Upper Boundary zone. Altogether, the inferred underground resource would be 8.6 million tonnes grading 3.8 grams per tonne.

A single resource for the whole project, using consistent methods, is planned for the next estimation. Micon grades were cut to 34.3 grams per tonne (1 oz. per ton), while the grades in the new estimates were cut to concentrations specific to the mineralized zone, based on statistical analysis. Those cutting levels ranged from 13.7 grams per tonne in the Lower Young Davidson to 20.6 grams per tonne in the Lower Boundary. The resource after cutting is about 11% smaller than one calculated using uncut grades.

Drilling from surface continues at the property. One new hole, YD06-27, intersected four gold zones in the area between the Lower Boundary and Lower Young Davidson zones. An 18.3-metre core length graded 7.06 grams gold per tonne, representing a true thickness of 15.4 metres. Three other intervals, ranging from 5.2 to 6.7 metres true thickness, graded in the 2.4- to 3.8-gram range.

Hole YD06-25, immediately west of hole 27, cut through two mineralized zones, one of 6.1 metres grading 3 grams gold per tonne and one of 27 metres grading 1 gram. The hole was steeply angled, so true thicknesses were slightly less than half the core lengths.

Other holes west of hole 25, near the middle of the steeply plunging Young Davidson zone, intersected somewhat wider mineralization, one cutting 31.1 metres grading 3.7 grams gold per tonne and another 79.3 metres grading 1.6 grams. The first had a true thickness of 19.6 metres and the second 62.8 metres.

Further downdip, hole YD06-21A intersected a 113.2-metre core length, representing 100 metres of true thickness, that averaged 1.8 grams per tonne.

Four drill holes in the Lower Boundary Zone, about 150 metres vertically and 150 metres east of YD06-27, also intersected significant widths of gold mineralization. A 58-metre interval in hole YD06-16C, representing 50.9 metres true width, averaged 2.2 grams per tonne near the western fringe of known mineralization.

Three daughter holes from YD06-20 all intersected mineralization at depths of 1,050 to 1,200 metres below surface. Hole 20C, the uppermost, cut 36.7 metres (31.2 metres true width) grading 4.1 grams gold per tonne; 20B, downdip, cut 53.4 metres (41.4 metres true width) running 1.9 grams; and 20A, the deepest, cut 2.4 grams over 19.2 metres, representing a true width of 13.7 metres.

Mineralization in holes 16C, 20B and 20C was brought into the resource calculation for the Lower Boundary Zone, but that in 20A has not been.