TORONTO, Dec. 05, 2017 (GLOBE NEWSWIRE) -- MacDonald Mines Exploration Ltd. (BMK.V) ("MacDonald Mines", the "Company", or “BMK”) announces that it has received gold and silver assays for 59 of 401 sonic boreholes completed in the Oxide Sands trend of its Wawa-Holdsworth Project. Of the 59 holes received to date, twenty-four had composite gold values greater than 1g/t over 1 metre.

An infographic accompanying this announcement is available at http://www.globenewswire.com/NewsRoom/AttachmentNg/9dbb8c86-dedf-4585-95e6-9eb5cf09914c

Table 1 highlights from the drilling results are tabulated below.  The spatial relationship between boreholes is shown in Figure 1.

*AuEq calculated using spot price of 1274.36 US$/oz for gold and 16.34 US$/oz for silver taken at market closure on December 1st, 2017. AuEq = (Grade Au) + [(Grade Ag)/(Gold Price/Silver Price)] (ratio rounded to 78). Drilling intersection reported as intersection length are estimated to represent >95% true width of the precious-metal rich layer of the soil formation.

Figure 1. Plan map of trenching locations with gold AuEq values

Quentin Yarie, President and Chief Executive Officer of MacDonald Mines stated, "These first results from the sonic drilling have exceeded our expectations. Our trenching program helped us define the lateral extents of the Oxide Sands formation, but only sampled the surface materials. These results suggest that the precious metal materials are below 1/2 metre of surface and that there are likely high-grade gold and silver zones.”

Oxide Sands Sonic Drilling Results
Sonic drilling systematically tested all the trenches where precious metal-rich Oxide Sands were previously identified in order to establish the lateral and strike length continuity of the formation. The initial drilling results indicate excellent grade continuity of the Oxide Sands formation over a strike length of 200 m and a lateral extension varying between 3 and 15 m. With gold equivalent grade up to 17.2 g/t over 0.85 m, drilling results also indicate the potential of the Oxide Sands formation to contain high-grade zones rich in gold and silver.

Oxide Sand Resource Estimation
The Company is currently awaiting assay results for the remaining 342 holes drilled during its 2,000 m sonic drilling campaign. Once results are made available, the Company will initiate a NI43-101 inferred resource estimation for the Oxide Sands.

Overview of the Wawa-Holdsworth Project

• Neighbouring 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 2.1 km. This is corroborating the interpretation of the geophysical anomalies indicated by MacDonald’s MAX-MIN survey results.

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.

MacDonald Mines has implemented a quality-control program to comply with best practices in the sampling and analysis of both the Oxide Sands and drill core. As part of its QA/QC program, MacDonald Mines inserts external gold, silver, platinum and palladium standards (low to high grade) and blanks every 20 samples in addition to random standards, blanks, and duplicates.

Qualified Person
Quentin Yarie, P Geo. is the qualified person responsible for preparing, supervising and approving the scientific and technical content of this news release.