Drilling boosts Tambor

Bulk-tonnage potential is indicated by results from the first four reverse-circulation (RC) holes drilled on one of three targets to be tested at the Tambor gold property in central Guatemala.

While drilling the Lupita target, Radius Explorations (RDU-V) cut wide intercepts of sulphide gold mineralization in the range of 1-2 grams per tonne across widths ranging from 25.9 to 135.6 metres. The widely spaced holes were drilled vertically around a bathtub-shaped ridge in between nine hand trenches that had outlined a gently west-dipping, 25-metre-thick oxide gold horizon. The RC rig reached its operational limits in three of the holes, all of which bottomed in mineralization. The rig has been switched over for core drilling so that the fourth hole, which intersected 135.6 metres averaging 1.22 grams, can be twinned to confirm grade distribution, as well as to test the lower limits of the zone. The diamond drill rig has a depth capability of 450 metres.

Lupita is the first of the targets to be tested, and it was the lowest-priority target in that it was the lowest-grade, says consulting geologist Jeff Franzen. Lupita is the most eastern target.

Seven holes have been drilled at Lupita, with assays reported from four. The gold mineralization occurs in a carbonaceous phyllite unit in association with strong multi-stage hydrothermal quartz veining containing disseminated pyrite and arsenopyrite. A hangingwall amphibolite schist, sitting at the top, was unmineralized. One drill hole also cut the footwall, which was also amphibolite schist.

The RC holes hit a fault zone at the contact between the hangingwall amphibolite schist and the mineralized carbonaceous phyllite. Based on the differences in metamorphic grade between the two rock units, Radius believes the phyllites have been sliced into the amphibolite schist along a fault zone. The mineralized zone is dipping about 10 to the west. The oxidized mineralization exposed in the trenches is now believed to be just a thin skin or rind on surface. The mineralization intercepted in the drilling consisted entirely of sulphides.

The favourable phyllite horizon can be traced from Lupita for a distance of 4 km west to the Bridge zone, where it disappears under volcanic ash cover. For much of this distance, its inferred subcrop coincides with a gold-in-soil anomaly. Samples from scattered outcrops and hand trenches within the anomaly yielded values in excess of 1 gram. Previous channel sampling at the Bridge zone returned 85 metres grading 3.59 grams.

Once the twinned core hole at Lupita has been completed, the RC rig will move on to the higher-grade Sastre zone for several short holes. At the same time, Radius intends to bring in a larger-capacity RC rig to start a systematic stepout program and work its way toward the Bridge zone. “To make a project like this work, you’ve got to be looking at tens of million of tonnes,” says Franzen. “It’s like having the pot of gold underneath the four-leaf clover; the only thing is that, with this geochem anomaly that seems to go on forever, we have a whole field of four-leaf clovers!”

The Tambor property occurs in a new belt of rocks that have now been traced over a distance of more than 20 km. Regional work in the past 18 months has uncovered three large gold anomalies in this belt. Ten individual prospects have been identified, all of which will be eventually drilled.

Highlights from the first four holes on the Lupita zone area outlined in the accompanying table.

HoleIntervalWidthGold