Discovery Of Wide High-Grade Silver Zone Southwest Of San Marcial Resource Area

VANCOUVER - GR Silver Mining Ltd. reported a new silver (Ag) discovery in the first drill hole stepping out 250 m to the southeast of the San Marcial Resource Area on the wholly-owned Plomosas Project in Sinaloa, Mexico. Surface drill hole SMS22-10 intersected 101.6 m at 308 g/t Ag (from 98.5 m down hole), including multiple intervals grading over 1,000 g/t Ag. The hole was drilled 250 m to the SE of the San Marcial Resource Area, where the Company has been exploring the extension of the target contact between upper and lower volcanic units, which typically hosts the San Marcial Breccia Ag mineralization, together with strong ground magnetic anomalies delineated in 2021. The drilling to date in the new area has identified a more extensive breccia and stockwork mineralization, rich in Ag, immediately below the contact zone and extending mineralization far below the original target zone. This new, wide, high-grade silver discovery coincides with an inflexion in the NW-SE trending contact where it intersects with two key NE-SW trending faults. This defines a highly prospective target for continued drilling, both along strike and down dip.

Chairman and CEO, Eric Zaunscherb, said, "The discovery of wide, high-grade silver mineralization in this new area is not only evidence of the Plomosas Project's exploration potential, but also testament to the efficacy of the exploration model developed by our geologists. They have clearly 'dialed in', hitting impressive mineralization on a blind target guided by modern exploration tools and concepts. We look forward to continued exploration success and news flow from ongoing drilling, leading to an updated project Mineral Resource Estimate in Q1|23. In addition to wide intersections building tonnage, we are confident that the higher grades encountered in recent drilling may also be meaningfully impactful in the upcoming resource update."

Drill hole SMS22-10 represents a new discovery in the Southeast Area where no drilling had previously been undertaken. It is in this area that the Company has been targeting the extension of the contact that hosts the breccia mineralization at the San Marcial Resource Area. The discovery drill hole passed through the upper volcanic unit, consisting primarily of andesitic "block and ash" before reaching a hydrothermal breccia (similar to San Marcial Breccia-style of mineralization) at the contact with the underlying (lower) volcano-sedimentary unit. This coincides with the structural setting containing the mineralized San Marcial Breccia at the nearby San Marcial Resource Area. A silver-only mineralized, intensely brecciated and hydrothermally altered zone, intersected immediately below the typical San Marcial Breccia-style mineralization, hosts a wide, high-grade zone measuring 101.6 m and averaging 308 g/t Ag. This mineralized zone consists of an intercalation of hydrothermal breccias and quartz veining/flooding containing Ag sulphides (acanthite) and possibly other Ag sulfosalts.

The broad, high-grade interval commenced at 98.5 m down hole with the typical San Marcial-style breccia hosted in the contact between the upper volcanics and lower volcano-sedimentary unit. This hydrothermal breccia is composed of fine hematite cementing mainly lower volcano-sedimentary unit fragments with disseminated sulphides, both in the matrix and in the fragments. This interval returned exceptional Ag grades of 7,139 g/t Ag over 0.8 m (from 98.5 m). Visible sulphides include galena and sphalerite, while Ag sulphides are frequently fine grained and possibly hosted within the hematite.  At 102.9 m depth, this high-grade Ag breccia was followed by an interval containing 3,065 g/t Ag over 0.3 m.

The mineralization discovered below the San Marcial Breccia has a predominance of Ag in the interval from 106 to 171 m, where trace and disseminated Ag sulfosalts are present. This results in a wide, consistently mineralized Ag interval including higher-grade portions such as 1,774 g/t Ag over 0.2 m (from 116.1 m), 1,004 g/t Ag over 4.1 m (from 149.8 m) and 1,579 g/t Ag over 0.4 m (from 156.3 m). The presence of a quartz-sulphide event, which is frequently developed in subvertical E-W and NE oriented structures, cross-cutting the San Marcial-style breccia and volcano-sedimentary unit, delineates a pervasive stockwork-brecciated zone.

From 171 to 202 m, the stockwork-brecciated zone contains more quartz than hematite, demonstrating both subvertical and 45° to 55° dip angles with cross-cutting relationships possibly related to the presence of narrow subvertical dykes. This phase of mineralization consists of a more polymetallic quartz-sericite, acanthite, argentite, and minor galena-sphalerite assemblage, demonstrating consistent mineralization up to 414 g/t Ag over 16.2 m (from 184 m), including 1,405 g/t Ag, 1.9 % Zn and 0.8 % Pb (from 198.3 m). The discovery extends the known mineralized system 250 m from the edge of the San Marcial Resource Area. Recent mapping has identified major regional NE-SW fault systems likely located between the San Marcial Resource Area and the Southeast Area discovery zone.

The discovery of a new wide, high-grade Ag zone in the Southeast Area of San Marcial opens up the potential for significant additional mineralization to the SE of the San Marcial Resource Area. This drill success validates the excellent targeting work undertaken by the Company's technical team in the last two years, combining detailed mapping, interpretation of a recent ground geophysical survey and geochemical anomalies from an intensive litho-geochemical sampling program.

GR Silver Mining has identified several additional targets in the Southeast Area. Drill holes SMS22-11 to SMS22-13 have been recently completed and are currently being logged and sampled. Laboratory analysis for these holes is pending. Specifically, drill hole SMS22-12 was drilled below the SMS22-10 discovery hole, whilst an additional hole (SMS22-15) is currently in the early stages of drilling below SMS22-12. The Company anticipates that drilling will continue with two rigs over the coming months in the Southeast Area of San Marcial.