- In the original Homestake Mine, the ore consisted of hundreds of individual mineable ore bodies that occupied a mineralized zone called a “ledge”
- Ten such ledges were mined in the original mine and each ledge followed the axial trace of amajor syncline fold
- Each ledge has three geometric elements: an Upper Tail, Ore Centroid and Lower The vast majority of gold contained in a ledge is present in the Ore Centroid and into the Lower Tail region. Ore Centroids are characterized by broad intervals of high grade gold mineralization. Upper Tails contain some mineralization but this generally consists of discontinuous and erratic ore bodies that were not economic to mine.
Standby Mine Target
Fully permitted for drilling, subject to financing & COVID-19 restrictions
Persevering and continuation to drill-test targets
Enhancing existing Mineral Mountain data base
The Standby Mine Target is the most advanced gold exploration target in the Rochford District and is believed to possess the requisite volume of altered and gold-mineralized iron formation needed to contain a world-class ore body.
Gold mineralization in the Standby Mine and in historic drill holes is comparable to an Upper Tail position in a Homestake-type Ledge Target.
- Over the decades of in-mine exploration Homestake developed sophisticated methodologies to recognize Upper Tail environments and how to vector down- plunge along the structures to Ore Centroids. This proven successful approach is being utilized by Mineral Mountain at the StandbyMine!
Homestake Mining Company was extremely interested in the Standby Mine and considered Standby to have the potential to host a world class gold resource perhaps comparable to the 9-Ledge ore body in the Homestake Mine that produced more than 9.5 million ounces of gold.
- The Standby Target Trend is approximately 200 meters wide and has been intersected for 1,800 meters down plunge (1,000 meters vertical depth) and remains open at depth.
- The Standby Target occupies a major syncline fold structure comparable to 9- Ledge in scale andhas seen only a modest amount of shallow drilling to date with a few deeper exploratory holes. This drilling argues the Homestake ledge- type model is valid.
- Comparisons between Standby and 9-Ledge are important. Upper Tail mineralization in 9-Ledge is erratic and only rarely contained gold values in the 1- 5 g/t Au Consistent ore-grade mineralization (>8 g/t Au over 5-10 m widths) in 9-Ledge does not develop until 1,200 meters down-plunge along the syncline from surface and the highest gold grades and widths in the ledge centroid do not occur until 1,500 m down plunge.
- By comparison the gold grades and widths encountered in the shallow and moderately deepdrilling in the Upper Tail environment at the Standby Mine target are highly encouraging and are significantly better than the early drilling results typically encountered by HMC during in-mine exploration for other blind ledges above their Ore Centroids.
- Ledge-type targets require persistence through multiple drill campaigns, although the prize of a potential 5-10 million ounce 9-Ledge scale deposit is enormous
All geologic, geophysical and drill results to date suggest a Homestake ledge-type target exists at Standby and is potentially of large scale. Mineral Mountain’s goal is to extend the Standby Mine gold mineralization down-plunge through systematic step-out drilling along strike and down-plunge in the Upper Tail to discover an Ore Centroid at depth.
- 50,000-60,000 tons of ore were mined historically from the Standby Mine before 1950, mostly from oxidized ores in four large open cuts connected by underground workings to a maximum depth of 130 Historic outcrop surface sampling from the walls and rim of the open cuts averaged 9.1 m @ 10 g/t Au with grab samples up to 38 g/t Au. A shaft was sunk to the 130 m (425- ft) level and underground channel sampling assayed 10.1 m @ 6.0 g/t Au
- Historical drilling at the Standby Mine consists of 16,360 m (53,677 ft) across 45 core holes, all in the Upper Tail. MMV’s two previous core drilling campaigns between 2018 and 2020 extendedknown gold mineralization from the bottom of the historic Standby Mine workings from 130 metersbelow surface to a total plunge length of 850 meters.
- Mineral Mountain’s Phase 1 Program at Standby consistently defined Upper Tail- style mineralization over a 500 meter plunge extent below the historic mine workings, with drill intersections up to 0 m@ 2.12 g/t Au, including individual samples up to 9.0 g/t Au. A strong and persistent structural zonecutting altered prospective iron formation is present in all of these drill holes with local nodes of stronggold mineralization as expected.
- The results of Phase 1 and Phase II drilling suggest mineralization appears to be consistentlyincreasing in grade down-plunge along the structure toward the Ore Centroid!
- When combined with two historic drill holes by Homestake Mining Company, mineralization has been defined along a total plunge length in the Standby Mine Trend for 1,800 meters down-plunge.Importantly some of the best mineralization known in the structure occurs in the deepest drill hole, Homestake’s SM-87, which cut numerous gold intersections up to 3.05 m @ 10.23 g/t Au. At the time this was interpreted as the possible transition zone from the Upper Tail to the Ore Centroid.
Mineral Mountain’s proposed 2021 drilling program in the Rochford District will focus on the Standby Mine Target and is fully permitted for drilling, subject to financing and COVID-19 restrictions. The 9,000-meter drilling program as currently constituted will be focused on three target areas in general:
Several additional holes around MMV hole ST18-006, which cut 5 m @ 1.21 g/t Au includingseveral higher-grade internal zones such as 2.5 m @ 4.39 g/t Au and 1.50 m @ 5.24 g/t Au.
- This hole was near historic drill hole BLG-UG-03 that cut 91 m @ 3.19 g/t Au, including10.67 m @ 5.14 g/t Au.
- These intercepts were 100-150 m below surface and represent the opportunity to outline a near-surface high-grade ore shoot in the Upper Tail
Down dip and down plunge of a mineralized arsenopyrite-flooded intercept in the Poverty Gulch Formation cut in MMV hole ST19-011 (6.09 m @ 1.81 g/t Au).
- Mineralization of this type is rare and unusual in the rocks overlying the Rochford ironformation and likely represents structurally-controlled leakage from a better gold
- Where this arsenopyrite-rich shear zone cuts the underlying iron formation should be apotentially high-grade drill target in the crucial Upper Tail to Ore Centroid transition.
A series of proposed holes to intersect the same depth interval cut by historic Homestake Mining drilling in the SM-86 and SM-87 holes thought to be the upper parts of the Standby Ore Centroid.
- These historic holes represent a significant step-off along strike and down-plunge fromthe Standby Mine and the deepest historic exploration work performed at the Standby Target Trend (1,000 and 1,800 m down-plunge from surface respectively).
- These results were highly encouraging, including 05 m @ 10.23 g/t Au
- These two holes potentially intersected the crucial Upper Tail-Ore Centroid transition andneed to be replicated by MMV and further tested with systematic step-out drilling to confirminternally consistent high- grade gold is present
- Confirming the existence of an Ore Centroid at Standby would be a game-changingdiscovery for Mineral Mountain Resources and set the stage for future resource delineation drilling.