TORONTO, Dec. 07, 2017 (GLOBE NEWSWIRE) -- MacDonald Mines Exploration Ltd. (BMK.V) ("MacDonald Mines", the "Company", or “BMK”) announces that its sonic drilling program has discovered gold and silver in the bedrock underneath the Oxide Sands formation at its Wawa-Holdsworth Project. Table 1 highlights the sonic drilling results from the bedrock underlying the Oxide Sands.  The sonic drilling for the Oxide Sands was extended to “tag” bedrock wherever possible.

A map accompanying this announcement is available at http://www.globenewswire.com/NewsRoom/AttachmentNg/d4ac2110-23c3-419a-8b50-3c1e117712df

Table 1 – AuEq grades in sampled bedrock

*AuEq calculated using spot price of 1275.6 US$/oz for gold and 16.29 US$/oz for silver. AuEq = (Grade Au) + (Grade Ag)/(Gold Price/Silver Price)] (ratio rounded to 78). Drilling intersection reported as intersection length. Because of the limited penetration depth of the sonic drill into bedrock, no estimate of true width can be provided for the mineralization zone.

Quentin Yarie, President and Chief Executive Officer of MacDonald Mines stated, " The elevated sulfur content in bedrock assay samples rich in precious metals supports the conceptual association between precious metals in the bedrock and high sulfides. A large body of sulfides would explain the 1.8 km-long conductor associated with the Oxide Sands that was detected by the MaxMin survey we conducted earlier this year. This opens up a much larger potential as there are numerous other similar conductors on the property. This also suggests that the Oxide Sands are the oxidized cap of a sizeable shear zone extending to depth that is mineralized in gold and silver.”

Sonic Drilling Results in Bedrock
For each drill hole of its sonic drilling program, the Company collected, when possible, a short sample of the bedrock. Because of the limited penetration capabilities of a sonic drill into bedrock, the bedrock samples were relatively short.

The 1) observation of elevated gold and silver in bedrock samples, 2) the distribution of these samples over the 200m-strike length covered by the assay results received to date, 3) and the systematic deformation observed in the footwall and hangingwall of the structure defining the Oxide Sands trend, suggest that the Oxide Sands represents the oxidized cap of a large gold-bearing shear zone.

The elevated concentration of sulfur in most bedrock samples enriched in gold and silver indicates a spatial association between precious metals and elevated sulfides. This association suggests that the 1.8 km-long MaxMin conductor detected by the Company, is mapping a sulfide-rich shear zone with elevated gold and silver content.

The Company anticipates that results from the remaining 342 drill holes will corroborate these initial findings and that further investigation of the metal-bearing shear zone will likely be undertaken, once all sonic drilling assay results are made available. 

Overview of the Wawa-Holdsworth Project

• Neighboring Alamos' Island Gold Mine, Argonaut's Magino Gold Project and Goldcorp’s Borden project
• Numerous gold showings with diversified mineralization styles occurring in a 500 metres-wide deformation corridor
• Year-long road access and easy access to rail, road, electrical power, labour force and suppliers

Historic work by previous operators defined three gold targets on the Wawa-Holdsworth Project:

• Greenstone-hosted quartz-carbonate vein deposit (Soocana Vein System and Reed-Booth Showing);
• BIF-hosted gold deposits (gold-bearing pyrite zones in an Algoma-type iron formation);
• Gold-bearing Oxide Sands developed from the weathering of the auriferous pyrite zones.

MacDonald Mines is focusing its near-term exploration program on the Oxide Sands. Assays results received so far support that the precious metals-rich sand formation occur over a 1.1 km strike length. Assays pending, the observation of Oxide Sands in the trenching and drilling west of line 1700 indicate that the favourable soil formation containing the Oxide Sands may have an overall strike length of approximately 1.8 km. This is corroborating the interpretation of the geophysical anomalies indicated by MacDonald’s MAX-MIN survey results (see July 6, 2017 News Release)

Positive preliminary metallurgical results (see July 11, 2017);

• The concentration ratio of gold in rougher flotation averaged 6.0:1
• The concentration ratio of silver in rougher flotation averaged 5.2:1
• Reduction of feed volume in rougher flotation by approximately 85-90%
• The Oxide Sands can be processed by a simple crushing/flotation process
• No caustic treatments are necessary
• The processing will require low power requirements
• The waste material is inert (>70 percent silica/quartz)

The soft and relatively unconsolidated Oxide Sands material can be extracted like an aggregate. The Company’s trenching and sonic drilling programs completed earlier this fall were designed to better define the Oxide Sands in preparation for their potential extraction.

On-site Quality Assurance/Quality Control (“QA/QC”) Measures
Sand samples were transported in security-sealed bags for analyses to Activation Laboratories Ltd. in Ancaster, Ontario. Individual samples are labeled, placed in plastic sample bags and sealed. Groups of samples are then placed into durable rice bags and then shipped. The remaining coarse reject portions of the samples remain in storage if further work or verification is needed.