Polar Star Mining Corporation (TSX: PSR) today announced assay results from eight additional holes drilled in Zones A and B as part of its ongoing program of diamond drilling at its wholly owned Montezuma Project in Chile.
"All drill holes in Zones A and B have generated encouraging results that demonstrate the large extent of copper mineralization within the porphyry systems in these zones," said Doug Willock, President and CEO. "The new data further indicate the presence of copper mineralization over extensive areas and to depth. Given our large, 501 square kilometre land base at Montezuma, there is strong potential for additional discoveries as exploration proceeds this year."
To date, 31 diamond drill holes have been completed and two are currently in progress. Complete assays have now been received for the first 23 drill holes, of which 15 have been previously released. Eleven of these - 31, 32, 33, 35, 37, 41, 44, 46, 48, 50 and 52 -- were drilled in Zone A and eight - 38, 42, 43, 45, 47, 49, 51 and 53 -- were drilled in Zone B.
- The ongoing diamond drill program continues to expand on and confirm the exceptional size of the copper and gold bearing porphyry systems discovered in Zones A and B, both of which are open along strike and at depth.
- The gold-rich system in Zone A has been intersected over a strike length of 1.5 kilometres and to a vertical depth of 384 metres. New enhanced satellite imagery suggests that this mineralized structural zone continues to the north through Zone C and is at least six kilometres long.
- The porphyry system in Zone B has been intersected over a surface area of about 2.5 square kilometres and a vertical depth of 1.1 kilometres. By comparison, Antofagasta plc's new $2.3 billion Esperanza Mine's orebody (1.3 billion tonnes grading 0.45% Cu) is reported to have a footprint of 0.28 square kilometres.
- Of the newly released results, intercepts include:
- Zone A: 37 metres of 0.28% copper equivalent ("Cu Eq") in Hole 46 and 22 metres of 0.28% Cu Eq in Hole 52
- Zone B: 19 metres of 0.39% Cu Eq in Hole 47, 30 metres of 0.25% Cu Eq in Hole 47, 19 metres of 0.36% Cu Eq in Hole 49 and 33 metres of 0.33% Cu Eq in Hole 51.
- Leached cap and secondary copper sulphide enrichment zones are exposed at surface and were cut in four holes over a surface area of about one square kilometre in Zone B.
- The secondary copper sulphide enrichment zones in the drill holes range in thickness from four to 70 metres and grade up to highs of 1.74% to 3.5% Cu over four metres.
- A near surface zone of exotic copper minerals, mainly copper wad and cupriferous limonite, were also intercepted in several holes in Zone B.
- Primary copper-gold mineralization is associated with classic phyllic and potassic alteration shells. These shells and the secondary copper sulphide zones are characteristic of Chilean mega copper porphyry deposits.
- Zones A and B are two of nine target zones, each two to four kilometres long, defined by Polar Star's detailed geological, geochemical and geophysical surveys.
- The 20,000-metre diamond drill program announced January 12, 2011 has commenced.
Phase III Reconnaissance Diamond Drill Program
Of the 31 holes drilled to date, assay results have now been received from the first 23.
To put these intercepts in context, the published discovery intercepts for the Toki deposit of Codelco (2.6 billion tonnes grading 0.49% copper) were 24 metres averaging 0.30% copper and 21 metres averaging 0.27% copper.
The 11 holes completed during this phase of diamond drilling Zone A outline a 1,500-metre, pyrite-rich auriferous zone that appears to be an imbricate thrust zone separating a generally barren upper volcanic plate from an underlying altered intrusive complex. The presence of chalcopyrite-rich phyllic and potassic altered intrusive clasts within the thrust suggest the presence of a porphyry system in the lower plate. The zone varies in thickness from 26 metres in Hole 32 to 360 metres in Hole 46. Drill hole mineralogy and assays indicate that the mineralized zone has a copper-enriched top and zinc-enriched base. Re-evaluation of the prior reverse-circulation drill holes in Zone A and enhancement of new satelite imagery of the area suggest this mineralized structure zone continues to the north through Zone C. If so, its minimum strike length is in the order of six kilometres.
The 12 holes completed during this phase of diamond drilling in Zone B outline an extensive zone of disseminated and veinlet pyrite-chalcopyrite mineralization in porphyry style phyllic to potassic alteration. This porphyry system covers a surface area of at least 2.5 square kilometres and is continuously mineralized to a vertical depth of at least 1.2 kilometres. This mineralized zone occurs below a cover of younger unaltered volcanics and or leached cap varying in thickness from 220 metres in Hole 38 to 48 metres in Hole 56.
Secondary chalcocite-pyrite enrichment zones have been encountered within and at the leached cap - hypogene sulfide contact in Holes 38, 43, 45, and 51. This zone varies from three layers of four to 16 metres thick averaging 0.25% to 0.38% Cu Eq in Hole 45 to 70 metres in Hole 38, which contains an intercept of 44 metres averaging 0.66% Cu Eq. The hypogene copper mineralization in all the holes to date occurs primarily within the phyllic zone. However, Holes 38, 45, 49 and 51 also cut the outer edge of the potassic zone at depths from 122 metres in Hole 49 to 935 metres in Hole 38. This outer potassic zone in Hole 38 contains a 68 metre section of 0.31% Cu Eq. In Hole 45 a 44 metre section contains 0.37% Cu Eq and in Hole 51 a 33 metre section contains 0.33% Cu Eq. Hole 45 also transitions into the silicic core zone at about 915 metres, exhibiting strong quartz-molybdenite stockwork veining.
Radiometric age dating of the mineralized intrusive from holes in both zones gave ages in the range of 38.5 to 39.7Ma (millions of years), comfortably within the 43 to 37Ma range for mineralized intrusives in both the Chuquicamata and Esperanza mining districts.
The target widths Polar Star is pursuing at Montezuma are those comparable to the typical widths of economic ore bodies in the Chuquicamata district to the north of Montezuma, and can range from as narrow as 85 metres in the case of Codelco's Ministro Hales deposit to approximately 600 metres with Codelco's main Chuquicamata deposit. The Ministro Hales deposit has a resource of 1.3 billion tonnes at a grade of 0.95% Cu. To the south of Montezuma, Antofagasta plc's new $2.3 billion Esperanza Mine's orebody (1.3 billion tonnes grading 0.45% Cu) is reported to have a footprint of 0.28 square kilometres - about one-tenth of the surface area covered by the currently known extent of the porphyry system in Zone B.
The Company believes that the results to date from this phase of drilling continue to confirm and expand the size of the two porphyry systems discovered in Zones A and B. This phase of widely spaced anomaly evaluation has now been completed in Zones A and B. Once the remaining assays from these zones have been received, a detailed analysis of all geological, analytical and geophysical data will be carried out with a view to targeting the most economically prospective sections of the two systems. Once such a target has been confirmed by drilling, Polar Star will then plan for follow-up resource definition drilling. In the meantime, drilling will continue to evaluate Zones C to G.
The drill program is being carried out under the direction of Terence Walker, M.Sc., P.Geo., a qualified person within the meaning of National Instrument 43-101. Mr. Walker has reviewed the contents of this news release. All the analysis was done at ALS Chemex Laboratory in Coquimbo, Chile and Lima, Peru. Routine gold analysis was carried out on 30g sub-samples using a fire assay pre-concentration and atomic absorption spectro-photogrametric (AAS) finish. Samples with gold or silver values greater than 10g/t were re-analyzed by fire assay and gravimetric finish. Copper and 48 other elements including silver were routinely analyzed by the ICP technique following a hot four acid digestion. Samples with copper, zinc and lead values greater than 1% were re-analyzed using a hydrofluoric-nitric-hypochloric acid digestion, hydrochloric acid leach and AAS finish.
Source: Polar Star Mining Corporation