New Jersey Mining Company has announced that a massive interval of possibly bulk-mineable gold mineralization, contiguous to the open pit, has been intercepted in a recent core-drilling program.
The core drill hole GC 18-175, informally known as the “layback” hole, was newly completed to 96.1 m. The open pit was drilled previously on 25-m centers, and as a result, the layback hole was engineered to fill in a gap in an earlier core-drilling program to assess the possibility of expanding the pit to the north.
- The core drill hole GC 18-175 returned 1.0 g/t gold over 33.6 m true thickness beginning from 40.7-m depth beneath the surface of the ground including 3.26 g/t over 3.7 m just beneath the Idaho Fault.
The layback drill results show a remarkable pervasiveness and consistency of low-grade gold mineralization, perfect for bulk-mineable, open pit mining. This demonstrates the potential for open pit expansion— just as the structural characteristics and narrower, high-grade mineralization in the Paymaster holes announced last week are supportive of future underground mining in that area.
Rob Morgan, VP of Exploration, New Jersey Mining Company.
The layback hole had a continuous sampling run beginning at 40.7 m, wherein 32 of the 34 samples hosted anomalous gold. Through the drilling program, the Idaho Fault was successfully encountered at 62.5 m, and in addition to this, brecciated, banded, and massive quartz veins were identified in the favorable quartzite host rock in the first 10 m beneath the fault. Within the core, both visible gold and Galena were seen.
The results of the layback hole and the Paymaster holes continue to show the strength of the Golden Chest’s mineralizing system. As previously stated, ‘Our drill programs are focused largely on pre-development and development drilling at the Golden Chest—in support of current production at the open pit and ahead of production underground’. The flexibility of our approach and accuracy of hole placement would not be possible without the hands-on experience of mining on the surface and underground. I cannot overestimate the skillsets of our team, including what the drill brings to this business.
John Swallow, CEO and President, New Jersey Mining Company.
The earlier core drilling on 25-m centers, the 2017 trenching data, and results from the layback hole will be integrated with the innumerable number of open pit bench assays to assess the potential for pit expansion to the north. It has been anticipated that this engineering analysis will be completed in the next few months, including metallurgical testing intended to identify an efficient process to treat the material of lower grade.
About 56,500 tons of material less than the mill cutoff grade of 1.8 g/t gold has been stockpiled at the mine, and about 71,000 tons of mineralized material with an average grade of 3.60 g/t gold have been mined from the pit and then milled at the New Jersey Mill. In the waste rock storage site at the mine, about 410,700 tons of material has been placed.
Quality assurance/quality control
Idaho-based American Analytical of Osburn—an ISO certified laboratory—analyzed all the samples. Sample analysis was done through lead collection fire assay with a gravimetric finish. As part of a quality assurance-quality compliance program, a range of known assay standards have been submitted with each drill hole.