Gravity survey confirms target at Navidad (August 20, 2003)

Vancouver — The results of gravity and magnetic ground geophysical surveys have enhanced the potential for finding significant sulphide mineralization on the Navidad polymetallic project in Argentina.

IMA Explorations (IMR-V) identified two major gravity anomalies, the largest of which indicates a surface footprint measuring 800 by 1,100 metres. The target correlates with portions of a 1,600-by-1,300-metre induced-polarization chargeability anomaly.

The junior ran the survey in order to outline zones where the rocks have higher-than-average density. According to the company, the areas where the gravity anomalies overlap with zones of high chargeability values are probably zones of sulphide mineralization.

Situated in north-central Chubut province, Navidada is wholly held by IMA. The project centres on newly discovered bonanza-grade feeder structures hosted by felsic-flow dome rocks that partially outcrop along the crest of Navidad Hill. These high-grade structures and peripheral calcite-barite veins occur in a core area measuring 475 metres long by 60-140 metres wide. The exposed structures, often obscured by a thin slope cover, range in thickness from less than 1 metre to 3.3 metres and have been mapped over a cumulative strike length of 636 metres.

The average grade of 119 chip samples collected across the structures is 5,546 grams silver (162 oz.) per tonne, 9.8% lead and 3.8% copper. Based on the results of soil sampling and a few isolated rock samples, IMA’s geologists believe the bonanza-grade mineralization and flow dome may extend farther to the southeast beneath a thin cover of post-mineralization volcanic tuff.

Mapping has identified several areas of significantly mineralized “carapace breccia,” a thin unit occurring along the margins of the felsic volcanics. In total, 50 chip samples were taken from three areas measuring 150 by 50 metres, 20 by 18 metres, and 25 by 20 metres, and these samples averaged 3,785 grams silver (110 oz.), 2.1% lead and 3.7% copper.

IMA recently completed a grid soil-sampling survey that outlined elevated levels of silver-lead-copper over the entire 5.8-km-long survey length, including spectacular values of up to 531 grams silver, 2.39% lead and 574 parts per million (ppm) copper from areas outside of Navidad Hill.

The soil survey saw a total of 958 samples collected at 50-metre spacing on lines set 100 metres apart, or 50 metres apart in key areas. A strong soil anomaly measuring 1,700 by 300 metres covers the Navidad Hill and Galena Hill areas. It is defined by greater than 2 grams silver and generally greater than 100 ppm copper. Within this zone is a central, 600-by-200-metre core of greater than 10 grams silver in soils (including values of up to 298 grams silver). Portions of this central zone correlate well to the outcropping bonanza-grade feeder structures. Two other significant soil anomalies were outlined at Barite and Calcite Hills.

The large gravity anomaly, which, doughnut-like, has central low values surrounded by higher-density values, lies in the Galena Hill area. Amplitudes of this anomaly range from 0.6 to 0.8 milligals above the background results and, and it is smaller than the partially coincidental chargeability anomaly. Part of the gravity anomaly is spatially associated with breccia-hosted mineralization on surface.

The second gravity high measures 260-by-550 metres and lies in the Navidad Hill area. The target covers the portion of the flow dome that is known to host bonanza-grade mineralizing structures.

The newly run magnetic survey confirmed that the large chargeability and gravity anomalies are not caused by magnetic minerals, such as magnetite or pyrrhotite.

The Navidad discovery is hosted in an Upper Jurassic series of mixed calcareous sediments and intermediate volcanics known to government geologists as the Canadon Asfalto formation. A series of felsic flow domes has intruded into a basin that is generally filled with carbonates. Carapace breccias are peripheral to the domes and overlie them.

IMA’s geological team has mapped large areas of consistent, replacement-style galena matrix breccia over a cumulative strike length of several kilometres within a 5.8-km-long, elevated metal soil anomaly. Early sampling of this matrix style of replacement mineralization yielded an average grade of 158 grams silver per tonne and 8.9% lead from the first 41 randomly collected chip samples.

With winter weather quickly bringing IMA’s field season to a close at Navidad, the company’s technical team is preparing for an initial drill program of 4,000-6,000 metres.

IMA boosts a market capitalization of over $50 million and recently hit a 52-week high of $2.10, well above its yearly low of 34.