Kookaburra works to increase Tacaza grade

Diamond drilling at the Tacaza copper project in Peru is returning improved grades for Kookaburra Resources (KOB-T).

Kookaburra completed some 7,700 metres of reverse-circulation drilling on the property in 1994, outlining a geological resource of 4.4 million tonnes grading 1.35% copper, based on a cutoff grade of 0.5% copper.

That work proved disappointing in light of the previous resource estimate of 4.5 million tonnes grading 4.5% copper made by a Peruvian banking group, based on underground sampling results.

Kookaburra’s current program is testing a theory that a significant amount of copper was lost in the reverse-circulation drilling.

Only one of the 12 diamond drill holes completed to date showed lower values (18%), while the remaining 11 holes assayed up to 175% higher for copper.

The greatest improvement came from Hole 6 which returned 16 metres grading 5.6% copper, compared with the twin reverse-circulation hole which returned a grade of 1.5% copper.

Mineralization at Tacaza is hosted in relatively flat-lying copper oxide and supergene-enriched secondary copper sulphide horizons. The 1994 drilling covered a 900-by-2,300-metre area partially underlain by old workings from which the property vendors had been conducting selective underground mining.

Several holes are now being drilled west of the Tacaza deposit in an attempt to expand the resource.

Assay results from the recent diamond drilling are as follows:

*increase in copper grade when compared with the corresponding 1994 reverse-circulation drill hole.