A high-grade silver discovery in the Patagonia region of southern Argentina has
The Navidad discovery is believed to be part of a shallow subaqueous epithermal system that deposited silver enriched sulphides at or near the sea floor. IMA has identified a large mineralized system with two key features: a high-grade section measuring several hundred metres, and a lower-grade bulk-tonnage target that extends for several kilometres.
An IMA geologist discovered Navidad while on a routine site visit to investigate satellite imagery. The Navidad Hill zone contains bonanza-grade silver structures in a felsic volcanic flow-dome. In total, 43 chip samples average 6,537 grams silver per tonne, 3.5% copper and 16.6% lead. These high-grade structures are believed to represent feeders to mineralization that comprises extensive areas of sulphide replacement of unconsolidated volcanic breccias.
Replacement-style mineralization occurs in a heterolithic breccia in varying intensity over an area measuring 3.8 km long by 250 metres wide. Previously reported sampling of the mineralized breccia averages 158 grams silver and 8.9% lead. New sampling of portions of the replacement-style mineralization near the felsic flow-domes has returned up to 4,012 grams silver, 2.4% copper and 22.3% lead. This replacement mineralization with much higher silver grades appears to occur adjacent to flow-domes.
Recently completed preliminary petrographic work on surface samples indicates Navidad Hill bonanza-grade structures contain fine-grained argentite-acanthite, galena, chalcocite and lesser copper-silver-lead chlorides and oxides. The replacement-style mineralization consists almost entirely of silver bearing galena; no discrete silver minerals were identified petrographically.
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