GR Silver Mining (TSX-V:GRSL) Ltd has released wide and high-grade silver results from its surface infill drilling program at the Plomosas project in Mexico’s Sinaloa state that suggest the potential to significantly increase grade in some areas of the resource model - and improve the average silver grades for its next resource estimation.
The company said the infill drilling program initially focused on unmined areas close to surface when it began in December 2021 and is now progressing with a focus on underground infill drilling with three drill rigs.
"From the time of the release of the technical report for the Plomosas project in October 2021, it was clear that new infill drilling could offer the opportunity to improve the grade of the mineral resource estimate by addressing unsampled or under-sampled areas in the block model,” the company’s chairman and CEO Eric Zaunscherb said in a statement. “In addition to the expansion of mineralization to depth and along strike at San Marcial, it is GR Silver's priority to address the questions about grade at the Plomosas Mine.”
READ: GR Silver Mining says drilling confirms wide, high-grade silver mineralization below San Marcial resource in Mexico
The company said the infill drilling program targeted intervals on the upper levels of the historical Plomosas underground mine where unsampled intervals of historical drill holes within the mineralized zone were assigned zero values, and hence affected the grade of model blocks, in the 2021 NI 43-101 mineral resource estimation.
It noted that Phase 1 drilling has defined wide, high-grade predominantly silver-rich mineralization in the upper levels (up to 160 metres below surface) of the historical Plomosas mine.
High-grade silver results include:
- PLS22-05A: 24.2 metres (m) at 1,094 grams per tonne (g/t) silver (1,180 g/t silver equivalent), including 0.6m at 7,178 g/t silver (7,367 g/t silver equivalent)
- PLS22-06: 18.2m at 289 g/t silver (297 g/t silver equivalent), including 5.4m at 690 g/t silver (701 g/t silver equivalent)
- PLS22-04: 13.2m at 410 g/t silver (505 g/t silver equivalent), including 2.8 m at 1,323 g/t silver (1,447 g/t silver equivalent)
- PLS21-36: 9.8m at 541 g/t silver
- PLS21-38: 9.6m at 486 g/t silver
GR Silver said closely spaced drilling at Plomosas, with line spacing averaging 50m to 100m, was designed to obtain representative silver grades to improve the resource block model.
“Historical production at the Plomosas mine amounted to 2.5 million tonnes averaging 190 g/t silver, 0.92 g/t gold, 2% zinc and 2.4% lead,” Zaunscherb added. “It is deeply satisfying to see the ongoing infill drill program demonstrating grades materially higher than interpolated in the resource model, and over attractive widths.”
The company said a total of nine holes have been completed on surface to date in 2022 and confirm consistent high-grade silver mineralization in areas of previously unsampled historical drill hole intervals, where a zero silver grade was applied in the NI 43-101 report issued on October 8, 2021. The results also confirm the presence of predominantly high-grade silver zones close to the surface in unmined areas, it added.
Additional drilling is anticipated, as part of the current underground infill drilling program. Upon completion of the 2022 drill program, GR Silver said it expects to commence a resource upgrade for the Plomosas Mine Area.
The company also announced that it has received TSX-V approval for the shares-for-debt transactions announced on April 14, 2022, and consequently has issued 136,909 common shares to settle debt of $33,542.87.
GR Silver Mining (TSX-V:GRSL) controls 100% of two past producer precious metal underground and open pit mines, within the expanded Plomosas project, which includes the integrated San Marcial Area and La Trinidad acquisition.
As well as its portfolio of early to advanced-stage exploration targets, the firm holds 734 square kilometres (km2) of concessions containing several structural corridors totaling over 75 km in strike length.
Contact the author at stephen.gunnion@proactiveinvestors.com