Colossus Minerals Inc.

Colossus Minerals Inc.

August 04, 2009 14:32 ET

Colossus Minerals Inc.'s Check Assays Yield Higher Precious Metal Grades

TORONTO, ONTARIO--(Marketwire - Aug. 4, 2009) - Colossus Minerals Inc. ("Colossus") (TSX:CSI) is pleased to announce the results of check assays for gold, platinum and palladium as well as new full platinum group elements (PGE's) suite assays on Phase I drilled materials from the Serra Pelada Project, the Colossus-COOMIGASP joint venture located in Para State, Brazil.


- The new assays indicate higher grades of gold, platinum and palladium for most drill-holes, for example: SPD-001: 77.30 metres at 7.39 g/t gold, 14.49 g/t platinum and 15.19 g/t palladium (vs. 77.30 metres at 6.50 g/t gold, 6.93 g/t platinum, and 7.74 g/t palladium);

SPD-002: 48.25 metres at 30.57 g/t gold, 10.96 g/t platinum and 15.38 g/t palladium (vs. 48.25 metres at 23.37 g/t gold, 8.77 g/t platinum, and 11.21 g/t palladium);

SPD-018: 44.00 metres at 27.32 g/t gold, 1.90 g/t platinum and 3.25 g/t palladium (vs. 44.00 metres at 19.06 g/t gold , 1.75 g/t platinum, and 2.96 g/t palladium);

- Very high grade samples generally have assayed substantially higher in gold, platinum and palladium, individual samples assaying more than 600 g/t gold, 500 g/t platinum and 400 g/t palladium;

- High grades of rhodium (up to 5.92 g/t over 2.05m) and also iridium were encountered in high grade PGE samples although PGE ratios are extremely variable.


A broad suite of pulps from Colossus' Phase I drilling program was assayed for gold, platinum and palladium plus other PGE's by Genalysis Laboratory Services Pty. Ltd. (Perth laboratory). In addition to providing further information on the distribution of the full PGE suite at Serra Pelada, this assay program served as a check on previously announced results for gold, platinum and palladium, essential in view of the difficulties of assaying very high grade gold-platinum-palladium materials. Phase I drilling was focused on the Central Mineralised Zone ("CMZ"), which overprints metasediments occupying the hinge and inner limbs of a northwest-facing, southwest-plunging, reclined synclinorium that plunges gently southwest from the historical open pit. The CMZ is characterised by intense hydrothermal carbonaceous- and argillic alteration, inboard of siliceous alteration partially mantling the synclinorial hinge. See drill sections plus a plan view of Serra Pelada drill traces at

The new data for the PGE suite plus comparisons of gold, platinum and palladium assay sets for continuously mineralised core intervals from ten drill-holes are presented in the following table:

Gold values are significantly higher over substantial intervals in several drill-holes (SPD-002: upper interval, SPD-007 and SPD-018) compared with previous assays. This mainly, but not exclusively, reflects the higher gold assays (up to 600g/t gold) of high grade gold-platinum-palladium samples. In most other intervals the new and previous assay values compare favourably, variations between the datasets largely correlated with Lab1 assay batches. The lower gold and PGM grades of the lower interval in SPD-002 reflect blocks of assays in several Lab1 batches which are approximately twice the Genalysis values. Repeat & check assays have confirmed the Genalysis values, see TECHNICAL, below.

The new platinum and palladium values are substantially higher for several major intervals in drill-holes SPD-001, SPD-002 (upper interval), SPD-007, SPD-008 and SPD-010. This largely, but not exclusively, reflects the very much higher new platinum and palladium assays (up to over 500 g/t platinum for example) for very high grade samples. The very high grade PGE sample in SPD-010 has an unusually high Pt/Pd but has withstood three repeat assays and appears to relate to a subzone in which Pt/Pd varies greatly.

In relation to the other PGE's, very high grades of rhodium (5.92 g/t Rh over 2.05m) were encountered in SPD-001 as well as +1g/t in SPD-007 and SPD-008. Unexpectedly high grades of iridium (+1g/t) were assayed in SPD- 001 and SPD-007. However the Rh/Pt varies greatly and appears to be lower in the central part of the Central Mineralised zone compared with the previously assayed more southerly high PGE subzones.

Vic Wall, Colossus' President comments "The new assay data for Serra Pelada Phase I drilling confirms the very high gold and PGE grades of parts of the Serra Pelada Central Mineralised zone. These results materially increase gold and particularly PGE grades over substantial intervals in several drill-holes which cross-cut the orebody. The results further indicate that significant portions of Serra Pelada's noble metal inventory is localised in very high grade subzones. This doesn't make resource estimation any easier, but high grade is a nice problem to have. The Serra Pelada joint venture is investigating potential underground access to and development of the Central Mineralised Zone which will facilitate underground drilling ahead of production initially of high grade subzones. In the interim, consistent with industry best practice, we will be doing some further check assays of previous drilling." With the completion of the check assay and re-assay program, assay results from current drilling will be expedited over the coming weeks.


Some 350 pulps plus reference materials and blanks as returned from the previous (Lab1) assay program were submitted to Genalysis Laboratory Services Pty. Ltd., Perth. The pulps represent assayed core intervals totalling 360 metres in ten Phase I drill-holes, and included a broad range of precious-metal grades and Lab1 assay batches.

Genalysis re-homogenized the pulps and the mixer mills were subject to quartz washes after each sample to eliminate potential sample carry over. Every fifth quartz wash was assayed for gold & PGE, generally indicating minimal sample loss to pulveriser vessel walls. Re-homogenization, as evidenced by check and repeat assays, was largely effective in minimising coarse gold effects, although variations in gold results for some high grade samples may reflect such sample heterogeneity. PGE results are more uniform.

25gm. fire assays for gold and PGE's utilised NiS collectors with ICP-MS finish. These data are presented in the table above. 23 check assays were done by this method. Genalysis performance on these checks, blanks and five certified reference materials (including very high grade gold & PGE standards) were all within acceptable ranges, as were new assays of reference materials utilised in previous assay programs. Genalysis assays of the latter exhibit far less scatter around recommended values for gold, platinum and palladium than results from Lab1.

25gm. fire assays for gold, platinum and palladium (85 repeats in all), utilising Pb-rich collectors with ICP-MS finish were performed by Genalysis on a selection of medium to high grade samples and for which substantial discrepancies with Lab1 assays were evident. Agreement between the Genalysis repeats and NiS fire assays is excellent for platinum and palladium and also for gold, generally within 10% even for bonanza samples, the repeats averaging slightly higher gold values.

Dr. Vic Wall, President of Colossus Minerals and qualified person under National Instrument 43-101, is responsible for this release and has verified the contents disclosed.

About Colossus:

Colossus is an exploration and development Company focused on mineral resource properties in Brazil. The Company is currently focusing its efforts on the high grade gold-platinum-palladium Serra Pelada project in Para State, Brazil. Between 1980 and 1986 Serra Pelada was host to the largest precious metals rush in Latin American history. Coverage by 60 Minutes of this famous mining rush can be viewed at the following link:

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