Claim Staking at McKinley
In late-2013, NJMC assembled the McKinley Project through mineral leases along with some unpatented mining claims and encompasses several prospects north of Riggins in central Idaho.
The target concept at McKinley is orogenic gold within the greenschist facies metamorphic rocks of the Riggins Group. There are major structures in the district and high-grade historic mines. The bedrock gold from these sources was a likely feeder into the significant placer gold production of the area. The Company is in the relatively early stages of evaluating the targets, but early results from rock sampling, mapping, and limited drilling from underground indicate the presence of high-grade gold hosted in sulfidized structurally controlled alteration zones and breccia.
The McKinley Project includes an option to purchase the historic McKinley Mine, located on 62 acres within the 4,443-acre land package. The McKinley Mine includes workings that total approximately 3,000 feet of drifting and cross cutting on five separate levels. NJMC’s 2014 channel sampling and drilling program focused on surface and subsurface areas of the McKinley Mine.
Historic underground sampling at the McKinley Mine reportedly returned significant high-grade gold with one 5-foot channel assaying 2.77 ounces per ton (opt) gold and a 10-foot channel assaying 0.75 opt gold. More recent underground sampling highlights include a 5-foot channel assaying 5.52 opt gold. Prior to 2012, there had been no modern exploration effort at the mine other than limited sampling in the early 1980s and an evaluation by Kennecott Exploration in the early 1990s.
Prior operators conducted a ground magnetic survey over the central portion of the property. The survey indicated potential major structures passing through the district that are associated with some degree of demagnetization. The McKinley Mine occupies a magnetic low, associated with a trend of hydrothermal alteration, on the margin of a larger magnetic high. Subsequent rock chip sampling by NJMC identified two areas, outside the McKinley Mine area and along this trend, with significant gold mineralization in outcrop: along Fiddle Creek, which crosses the southern portion of the property, and the Monarch Zone, about 3,000 feet south-southwest of the McKinley Mine. Both of these areas have seen historic prospecting but no significant development. Much of the area between these prospects remains completely unexplored.
With a mineralized trend that appears to be nearly three miles in length, as seen on the McKinley Project Location Map, the McKinley Project has demonstrated its district-scale potential.
NJMC launched a geologic mapping and rock sampling program from both surface and underground at the McKinley Mine. Geologists cut more than 500 feet of diamond saw channel samples from mine ribs and stoped areas in three separate zones on the main mine level. Highlights included a 14-foot continuous channel that returned a weighted average of 1.37 opt gold and a 5.7-foot continuous channel that returned a weighted average of 2.11 opt gold. Geologists used the high-grade mineralization to guide an initial drill program.
Drilling conducted by NJMC on adjacent property included 21 small diameter (B sized) core holes totaling 1,273 feet (388 meters) from within the underground workings of the McKinley Mine. Highlights included:
• DDH-02, which returned an 8.4-foot interval with a weighted average grade of 1.28 opt gold
• DDH-10, which returned an 11.3-foot interval with a weighted average grade of 0.54 opt gold.
The intervals reported are core length, not true thickness.
All of the holes are relatively short because of the use of a portable drill rig. The NJMC team custom engineered the core drill used at McKinley for the confined spaces of historic mine workings. While the custom drill has depth and angle limitations in its operation, it is also highly portable and does not require the construction of drill roads, realizing significant cost savings.
Eleven of the 21 drill holes encountered significant mineralization. Drill holes DDH-02 and DDH-10 extend one of the key mineralized zones in two directions from the existing mine stopes, down plunge to the northeast and up plunge to the southwest. The “water tank zone”, between the two holes, is now defined over approximately 100 feet of strike, of which 20 feet was historically mined.
Another drill hole, DDH-08, returned a 9.3-foot interval with a weighted average grade of 0.14 opt gold, extending a second zone of high-grade mineralization down dip from the historic workings. Mapping has confirmed that several of these newly discovered high-grade zones remain open.
The high-grade sampling and drill results at McKinley demonstrate its potential for future high-grade underground mining.