The most recent drilling at Corvus Gold’s (TSX: KOR; NASDAQ: KOR) Mother Lode property in Nevada targeted three vertically related zones at the 37-sq.-km property. Data from the eight holes reported continues to define a near-surface body of mineralization at the Upper Oxide zone, infill the Central Main zone sulphide resource with higher-grade intercepts, and outline a broad zone of mineralization at the Central Intrusive zone (CIZ), which was discovered in January.
Drill highlights from the Upper Oxide zone included 40 metres of 0.68 gram gold per tonne from 135 metres, and 14 metres of 1.03 grams gold per tonne starting at 128 metres. These additional intercepts are “defining a sizeable body of low-grade heap leach mineralization that will be beneficial to mining of the deeper, higher-grade deposit at Mother Lode,” by lowering the strip ratio, the company said in a statement.
Notable intercepts from the Central Main zone sulphide unit included 45 metres of 1.67 grams gold from 366 metres; 44 metres of 2.6 grams gold starting at 233 metres; and 73 metres of 1.92 grams gold from 116 metres. These results have infilled the resource model with higher grade hits, which is expected to “improve the grade and size of the mineral resource as well as its confidence level.”
At the Central Main zone, the drilling has also returned breccia zones from areas at the top of the CIZ structures, which cut the Central Main area and feature higher-grade gold areas that the company says is “a good sign of a dynamic and large gold system.”
Drill intercepts from the CIZ include 51 metres of 0.66 gram gold starting at 525 metres; and 29 metres of 1.67 grams gold from 244 metres. The latest results suggest a broad zone of gold mineralization, with variable widths, which remains open at depth. The mineralization is mostly oxides down to a depth of 600 metres, with initial cyanide leach results suggesting gold recoveries of over 90%, which Corvus says have good potential for heap leach gold extraction.
An additional hole completed towards the north end of the projected CIZ hit high-grade silver, returning up to 46 grams of the precious metal. Corvus views this as a potential indication of a “hotter, potentially more productive part of the system.”
Ongoing drilling at the CIZ is aimed at outlining the higher-grade shoots within this area. Additional metallurgical testing is also underway to understand potential processing pathways as part of a Mother Lode mine plan.
In a statement, Jeffery Pontius, Corvus Gold’s president and chief executive, highlighted the growth of the existing deposit and CIZ target.
“These new results continue to support the expansion of the Mother Lode deposit and the new CIZ target,” he noted. “The upgrading of the Main zone with core drilling is intriguing. We believe that these results could lead to an increase in the estimated grade for a future mineral resource estimate.”
Pontius also said that although the majority of the CIZ drill results will not be part of an upcoming preliminary economic assessment on Mother Lode, expected later this year, the assays will be accounted for in a resource update for Mother Lode in the new year, as well as drill results from the Lynnda Strip.
Measured and indicated resources at the Mother Lode project stand at 53.4 million tonnes at 0.68 gram gold for a total of 1.16 million oz., with additional inferred resources of 16.2 million tonnes at 0.46 gram gold for a total of 241,000 ounces.
The company also holds the 91-sq.-km North Bullfrog project, which borders Mother Lode. Both are located within the Bullfrog mining district host to epithermal gold systems. Mother Lode is a sediment-hosted gold system.
— This article first appeared in the Canadian Mining Journal, part of Glacier Resource Innovation Group.