GR Silver Mining Drills Two New Silver and Gold Mineralized Zones at San Marcial. SMS25-10A Returns 9 m at 374 g/t Ag including 1.0 m at 1,542 g/t Ag; and 33 m at 1.44 g/t Au including 1.2 m at 32.1 g/t Au
GR Silver Mining Drills Two New Silver and
Gold Mineralized Zones at San Marcial.
SMS25-10A Returns 9 m at 374 g/t Ag
including 1.0 m at 1,542 g/t Ag; and 33 m at
1.44 g/t Au including 1.2 m at 32.1 g/t Au
VANCOUVER, BC
,
Sept. 24, 2025
/CNW/ -
GR Silver Mining Ltd.
(
"GR Silver Mining" or the
"Company"
) (TSXV: GRSL) (OTCQB: GRSLF) (FRANKFURT: GPE) is pleased to announce
results from drill hole SMS25-10A, located in the Parallel Breccia Target, approximately 150 metres
(m) to the southwest of the current San Marcial Resource Area ("Resource Area") (Figure 1), in the
Plomosas Project. The step-out drill hole intersected
9 m
at 374 g/t silver (Ag), with anomalous
values of copper (0.3% Cu) and tungsten (0.59% W),
including a high-grade zone of
1 m
at 1,542
g/t Ag, 1.4% Cu, and 0.62% W (Table 1). This marks the first identification of this specific
mineralogical-chemical assemblage at San Marcial, supporting current exploration models that link
the wide silver mineralization to an intrusive porphyry-style geological setting.
In addition to the Ag-Cu-W zone, the drill hole returned a wide intercept of
33 m
at 1.44 g/t gold
(Au)
, including a high-grade interval of
1.2 m
at 32.1 g/t Au, defining a new gold-mineralized zone
along a NE-trending structural corridor in the Parallel Breccia Target outside of the current Resource
Area. These outstanding results have delineated mineralization styles with a signature of an
epithermal porphyry-related deposit that lies adjacent to the Resource Area.
Highlights of drilling at the Parallel Breccia Target, San Marcial
SMS25-10A
intersected two distinct mineralized zones, with apparently different mineralogical
compositions and origins, yet spatially associated and controlled by a NE-SW structural trend
that intersects major NW-SE regional structures.
9 m
at 374 g/t Ag, including significant grades of Cu and W, from
24.0 m
down hole;
33 m
at 1.44 g/t Au from
122.7 m
down hole.
SMS25-10A is the farthest southeast that a drill hole has been drilled in the Parallel Breccia
Target to date and indicates continuity of the mineralized structure over at least 500 metres
from the Resource Area.
The hole targeted the core of a high-chargeability geophysical anomaly that had never been
drilled before, Figure 3, while successfully confirming a high concentration of sulfide minerals
and associated silver, copper and tungsten mineralization.
High-grade gold values (
1.2 m
at 32.1 g/t Au) were encountered within a deeper, well-
developed quartz-calcite stockwork epithermal-style zone, confirming the potential of the NE
structural trend to host high-grade gold-bearing mineralization in the footwall beneath the
Resource Area.
SMS25-10A is characterized by halos of intense high-temperature alteration minerals in the
lower volcano-sedimentary unit, with a mineral assemblage of tourmaline-actinolite-albite-K-
feldspar, overprinted by quartz-pyrite alteration, and later crosscut by irregular chlorite-hematite
veining.
GR Silver Mining's President and CEO,
Marcio Fonseca
, commented,
"The ongoing success of
step-out drilling at the San Marcial Area in 2025 reflects the diligent and detailed exploration efforts
of GR Silver Mining's team, who continue to define new frontiers for silver discoveries along the
southwestern edge of the Sierra Madre Occidental. The identification of mineralogical
assemblages characteristic of porphyry-related systems, together with the presence of high-grade
gold zones, underscores the strong potential for further resource expansion at San Marcial."
Figure 1 Location Map – Drill Hole SMS25-10A Location in the Current Parallel Breccia Drilling
Program and Intrusive Related Chargeability Anomaly (CNW Group/GR Silver Mining Ltd.)
Table 1: SMS25-10A Drilling Highlights – Parallel Breccia Target
Drill Hole
From
(m)
To
(m)
Type
Interval
(m)
Ag
g/t
Au
g/t
Cu%
W
%
SMS25-10A
24.0
33.0
Hydrothermal
Breccia
9.0
374
0.08
0.3
0.59
(Incl)
32.0
33.0
Hydrothermal
Breccia
1.0
1,542
0.04
1.4
0.62
122.7
155.8
Stockwork
33.2
4
1.44
NA
NA
(Incl)
137.5
138.7
Stockwork
1.2
15
32.1
NA
NA
Note: Numbers may be rounded. Results are uncut and undiluted. True widths not estimated as the
Company does not have sufficient data from the new mineralized zones to determine the true
widths of the intervals with any confidence.
Drilling in the Parallel Breccia Target has confirmed the presence of new silver mineralized zones
500 metres from the Resource Area, directly over the core of a geophysical chargeability anomaly
and in close proximity to high magnetic anomalies, interpreted to be associated with a multi-phase
intrusive complex (Figure 1).
The potential for resource growth in the Parallel Breccia Target is demonstrated by the presence of
high-grade silver mineralization in drill hole SMS25-10A (
1.0 m
at 1,542 g/t Ag). The anomalous Cu
and W grades establish a possible relationship with the nearby intrusive centre, and a geological
setting amenable to further resource growth at San Marcial. Based on recent surface mapping and
3D modeling, this intrusive body is interpreted to be located just 150 metres below the bottom of the
SMS25-10A drill hole (Figures 2 and 3).
Successful drilling in the current program at the Parallel Breccia Target also confirms the
prospectivity of the NW-SE and NE-SW trends, not only within the Resource Area, but also in the
broader, open extensions of the lower volcano-sedimentary unit. This highlights the importance of
structural controls in generating wide mineralized zones that provide new and exciting exploration
targets.
The Company's geologists are further encouraged by the presence of gold-dominant, high-grade
mineralized zones in both SMS25-08 and SMS25-10A, separated by 150 metres horizontally and
below the existing Resource Area. The alteration textures observed in drill hole SMS25-10A also
provide an important vectoring tool for understanding zonation and proximity to a porphyry-related
system. Massive patches of tourmaline, actinolite-chlorite, albite, and K-feldspar (particularly in the
laminated levels of the lower volcano-sedimentary unit), along with an intense stockwork of quartz-
pyrite veining with albite halos, are commonly observed and increase in intensity with depth. These
features indicate that SMS25-10A may be approaching the intra-mineral phases of a porphyry
system (Figure 4).
Figure 2 Geological Map San Marcial Area – Parallel Breccia Target (CNW Group/GR Silver Mining
Ltd.)
Figure 3 Cross Section – Location hole SMS25-10A (CNW Group/GR Silver Mining Ltd.)
Figure 4 Drill Core Photo Illustration - SMS25-10A “Hydrothermal Breccia” (CNW Group/GR Silver
Mining Ltd.)
Table 2: 2025 San Marcial Step-Out Drill Program – Drill Hole Details
Drill Hole
Target
East (m)
North (m)
RL (m)
Dip (˚)
Azimuth (˚)
Depth
(m)
Results Status
SMS25-01
NW
Extension
450685
2546064
914
-60
160
247.8
Abandoned
SMS25-02
NW
Extension
450568
2546102
942
-55
135
206.0
Abandoned
SMS25-03
Parallel
Breccia
450955
2545667
862
-60
135
206.0
Received
SMS25-04
Parallel
Breccia
451045
2545757
860
-55
185
159.0
Received
SMS25-05
NW
Extension
450791
2545967
892
-47
227
176.7
Received
SMS25-06
NW
Extension
450797
2546016
895
-74
225
191.8
Received
SMS25-07A
Parallel Breccia
451145
2545641
795
-76
200
118.2
Received
SMS25-08
Parallel Breccia
451085
2545808
835
-65
175
244.5
Received
SMS25-09
SE Deep
Extension
451506
2545924
700
-60
130
424.2
Received
SMS25-10A
Parallel
Breccia
451506
2545924
700
-60
130
217.5
Received
SMS25-11
SE Deep
Extension
451262
2545587
708
-81
143
TBD
Pending
SMS25-12
SE Deep
Extension
451313
2546012
799
-68
270
TBD
Drilling
SMS25-13
SE Deep
Extension
451262
2545587
708
-62
280
TBD
Drilling
Note: all holes drilled from surface; WGS84 Datum; TBD - To be defined
About the Plomosas Project
The Plomosas Project, including the recent high-grade silver discovery in the San Marcial SE Area,
is progressing in 2025 as an emerging high-grade silver district located in southwestern edge of the
Sierra Madre Occidental,
Sinaloa, Mexico
. The Plomosas Project, covering 7,823 ha, including the
historical Plomosas Underground mine. benefits from mine infrastructure, road access and existing
permits associated with past-producing mining sites. The district contains intermediate to low-
sulfidation epithermal silver and gold mineralization, hosted in hydrothermal breccias and veins.
Recent success in exploration and drilling has delineated wide, high-grade, shallow hydrothermal
breccias in the San Marcial Area, including the SE Area discovery, where step-out drilling is
underway in 2025, aiming for continuous resource growth. At the historical Plomosas Mine, where
Grupo Mexico operated the underground mine from 1985 to 2000, exploration, underground
sampling and metallurgical programs are being conducted to support future decisions regarding the
implementation of a Bulk Sampling Test Mining Program.
QA/QC Procedures
The Company has implemented QA/QC procedures, which include the insertion of blank, duplicate,
and standard samples in all sample lots sent to SGS de México, S.A. de C.V. laboratory facilities in
Durango, Mexico
, for sample preparation and assaying. For every sample with results above Ag >
100 ppm (over the limit), these samples are re-assayed by SGS de
Mexico
. Core samples are
represented by both HQ and NQ diameters and samples are represented by ½ core split of original
core. The analytical methods include four acid Digestion and Inductively Coupled Plasma Optical
Emission Spectrometry, with Lead Fusion Fire Assay and a gravimetric finish for silver above over
limits. For gold assays, the analytical methods are Lead Fusion and Atomic Absorption
Spectrometry, Lead Fusion Fire Assay, and gravimetric finish for gold above over limits (>10 ppm).
Qualified Person
The Qualified Person under National Instrument 43-101 Standards of Disclosure for Mineral Projects
for this news release is
Marcio Fonseca
, P. Geo., President & CEO for GR Silver Mining, who has
reviewed and approved its contents.
About GR Silver Mining Ltd
.
GR Silver Mining is a Canadian-based,
Mexico
-focused mineral exploration company engaged in
cost-effective silver-gold resource expansion on its 100%-owned assets, located on the eastern
edge of the Rosario Mining District, in the southeast of Sinaloa State,
Mexico
. GR Silver Mining
controls 100% of the Plomosas Project, including the former Plomosas underground mine and wide,
high-grade silver mineralized zones at the San Marcial Area. Recent discoveries in the 78 km² of
highly prospective, advanced-stage exploration concessions position the Company well for resource
expansion at the Plomosas Project.
GR Silver Mining Ltd.
Márcio Fonseca, President & CEO
Cautionary Statement Regarding Forward-Looking Information
This press release contains "forward-looking statements" within the meaning of applicable
Canadian securities legislation and information that are based on the beliefs of management and
reflect the Company's current expectations. When used in this press release, the words "estimate",
"project", "belief", "anticipate", "intend", "expect", "plan", "predict", "may" or "should" and the
negative of these words or such variations thereon or comparable terminology are intended to
identify forward-looking statements and information. Such statements and information reflect
the current view of the Company. Risks and uncertainties may cause actual results to differ
materially from those contemplated in those forward-looking statements and information. By their
nature, forward-looking statements involve known and unknown risks, uncertainties and other
factors which may cause our actual results, performance or achievements, or other future events,
to be materially different from any future results, performance or achievements expressed or
implied by such forward-looking statements.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is
defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy
or accuracy of this press release.
SOURCE
GR Silver Mining Ltd.
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For further information, please contact: Telephone: +1 236-270-2057,
Email: [email protected]
CO: GR Silver Mining Ltd.
CNW 06:00e 24-SEP-25