EXPLORATION 1999 – Atna hits VMS-style mineralization in DR — Junior explorer adds to potential indicated by previous drilling

Early results from a planned 2,000-metre drill program in the Dominican Republic are boding well for Atna Resources (ATN-T).

The first hole drilled on the San Antonio I concession encountered 0.7 metre of copper-rich mineralization in the hangingwall before hitting a 1.5-metre interval of massive sulphides at the contact between the sediment and felsic volcanic rocks. The massive sulphide interval was intersected at a depth of 120 metres below surface.

Hole 1 was a 60-metre stepout, downdip of a previous hole (put down by former property-owner Battle Mountain Gold), which intersected a narrow 0.3-metre band of massive sulphides grading 16.9% zinc and 2.6% copper, plus 25.7 grams silver and 1.1 grams gold per tonne. Atna’s first hole shows a thickening of the massive sulphide horizon.

Atna intends to drill 7-10 holes in the current program; the next three will test the mineralization on 100-metre stepouts along strike.

Atna can earn a 60% interest in the 34.5-sq.-km concession from Energold Mining (EGD-V) by spending US$3 million on exploration over four years and issuing US$300,000 in shares.

The property lies 25 km south of the Pueblo Viejo gold deposit and 20 km from Falconbridge‘s (FL-T) Cerro Maimon volcanogenic massive sulphide (VMS) deposit. The latter contains and estimated 3.5 million tonnes grading 3.77% copper, 2.04% zinc, 46.4 grams silver and 0.6 gram gold.

San Antonio I forms part of the Maimon Formation, a northwesterly striking belt of shistose volcanic rocks that cuts across the central part of the country over a length of 75 km and a width averaging 10 km. The rocks are deformed and regionally metamorphosed.

VMS mineralization at San Antonio is totally blind with no surface expression. Previous work identified a 6,000-by-600-metre, multi-element, precious and base metal soil anomaly, with coinciding induced-polarization, chargeability and resistivity anomalies. Surface sampling of float boulders has returned gold values in the range of 1-5 grams, with highly anomalous base metal values.

In 1990, Battle Mountain Gold identified VMS-style mineralization after drilling four holes. One of these holes, SJ-2, intersected 15.6 metres of massive-to-semi-massive sulphides grading 1.2% copper, 0.5% zinc, 9 grams silver and 0.7 gram gold at the contact between sediments and weakly deformed intermediate felsic volcanics. A separate, 0.3-metre interval in the hangingwall yielded an average value of 0.9% copper, 15.2% zinc, 29.1 grams silver and 5.8 grams gold.

Another hole, SJ-4, stepped out 200 metres to the southeast and encountered a 0.3-metre interval of massive sulphide mineralization along the same sediment and volcanic contact. Atna’s first hole was drilled downdip of hole SJ-4.

Atna’s project geologist, Peter Daubney, says Battle Mountain’s holes may have intersected the tip of a massive sulphide horizon that exhibits classic VMS zonation in the core, with an underlying vein stockwork.