Austral Gold Reports Surface Silver-Gold Results at Juncal

• Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as downhole gamma sondes, or handheld XRF instruments, etc.). These examples should not be taken as limiting the broad meaning of sampling.
• Include reference to measures taken to ensure sample representativeness and the appropriate calibration of any measurement tools or systems used.
• Aspects of the determination of mineralisation that are Material to the Public Report.
• In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverized to produce a 30 g charge for fire assay’). In other cases, more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.

Within the program, 29 samples were collected from 25 distinct sampling points using the chip-channel sampling method. For this procedure, the channel boundary was geometrically outlined on the rock face, and the material was manually chipped out using a hammer and chisel to ensure the representativeness of the recovered fragments.

In addition, field reconnaissance is being conducted, where a geologist describes lithologies, alterations, and mineralogy found at various points recorded with a GPS. At these geological control points, representative samples are collected for distinct investigation workflows: one fraction is dispatched to the chemical laboratory for routine analytical assays (metal grades), while selected fragments are prioritised for mineralogical characterisation, including the preparation of thin and polished sections for petrographic and mineralogic studies.

• Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).

• Method of recording and assessing core and chip sample recoveries and results assessed.
• Measures taken to maximise sample recovery and ensure representative nature of the samples.
• Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.

• Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.
• Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography.
• The total length and percentage of the relevant intersections logged.

All sample logging has been supervised by experienced geologists.

Consequently, while the data are appropriate for conceptual geological modelling, supplementary diamond core drilling (DDH) providing undisturbed subsurface samples will be required in the future to fully support formal Mineral Resource estimates, advanced geotechnical mining studies, and comprehensive metallurgical recovery testing.

• If core, whether cut or sawn and whether quarter, half or all core taken.
• If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry.
• For all sample types, the nature, quality and appropriateness of the sample preparation technique.
• Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples.
• Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling.
• Whether sample sizes are appropriate to the grain size of the material being sampled.

No core drilling (diamond core) has been conducted within the project area to date. All samples originate from surface trenching campaigns. Consequently, this criterion is not applicable to the current stage of the project.

All collected samples are surface non-core samples, categorised into two types: mechanical saw-cut channel samples (602 samples from 53 distinct locations) and manual chip-channel samples (29 samples from 25 distinct locations).

All trench walls and channels were sampled under strictly dry conditions. Sampling during rain or on wet surfaces was avoided to prevent the loss of fines and to eliminate potential cross-contamination.

No downhole non-core splitting methods (such as riffle splitting or rotary splitting of reverse circulation drill chips) were performed in the field. The entire rock material from each channel was collected immediately into secure plastic sample bags at the site, yielding a primary sample weight of approximately 10 to 15 kg. Sub-sampling occurred later under control conditions at the analytical laboratory.

Sample Preparation Technique:
The technique was appropriate for the sample type, which includes and usually comprises oven drying, crushing, and pulverising to established parameters:

Drying (4 hours at 105° C), crushing to 85% passing 10 mesh, splitting and pulverizing 1 Kg to 85% passing #200 Mesh, and splitting into two pulps with approximately 200 g each. The primary lab was the Guanaco Mine laboratory.

To ensure high in-situ representativeness, all trenching points were thoroughly excavated and cleared of soil and weathered overburden to expose pristine rock faces. For the primary grid, a diamond-blade saw was used to cut precise, parallel lines into the rock face to guarantee uniform sample geometry and volume.

A specialised sampling chute was continuously placed directly beneath the channels during the chipping process (utilizing pneumatic hammers and manual hammer/chisel methods), ensuring that 100% of the fragmented material, specifically the critical fine fractions, were recorded directly into the sample bags without loss or ground contamination.

In addition, field duplicates were systematically inserted into the sample stream at an approximate insertion rate of 1 every 20 samples (5% insertion rate). A total of 31 field duplicates were analysed alongside the routine samples. Statistical evaluation of these field duplicates via scatter plots and Relative Absolute Difference (HARD) calculations demonstrates strong correlation and reproducibility, confirming the representative and unbiased nature of the in-situ extraction process.

• The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.
• For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.
• Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established.

The analytical techniques used by the primary laboratory (GCM) are standard and appropriate for evaluating epithermal and base-metal mineralisation styles within the project area.

Gold (Au) is analysed by fire assay using a 30 g charge. For samples returning lower grades (0.01 to 6.66 g/t Au), an Atomic Absorption Spectroscopy (AAS) finish is applied, while higher-grade samples (6.66 to 99.99 g/t Au), are analysed using a gravimetric finish. Fire assay is considered a total digestion technique for gold, and is generally regarded as providing complete extraction of gold from the sample matrix.

Silver (Ag), copper (Cu), zinc (Zn), and antimony (Sb) were analysed using AAS. Initially, the primary laboratory GCM used 4 ácid-ASS for Ag, Cu, Zn and Sb) digestion method to capture certain refractory phases concentrations. However, following an external laboratory element analysis (36 elements ICP-OES and 4 ácid-ASS for Ag, Cu, Zn and Sb), the limitations of the aqua regia method in recovering metals from certain refractory phases were identified.

The protocol defined was a 4-acid digestion (hydrofluoric, nitric, perchloric, and hydrochloric acids). A 4-acid digestion is considered a near-total digestion technique, capable of dissolving nearly all mineral matrices, including highly refractory silicates and complex sulfosalts.

Following the optimisation of the GCM protocol, a comprehensive re-analysis program was ordered for 100% of the trench and chip-channel samples, ensuring that the entire analytical database is homogenized under the superior 4-acid digest standard.

No handheld XRF instruments, portable spectrometers, or geophysical tools were used to determine the analytical grades for the 602 samples or the 29 chip-channel samples. All reported grades rely exclusively on formal wet-chemistry and destructive laboratory techniques (Fire Assay, 4-Acid Digestion, ICP-OES, and AAS) in accordance with industry best practices. Consequently, parameters regarding instrument calibration factors or reading times for field sensors are not applicable to this dataset.

Field duplicates were systematically inserted into the sample stream at 5% insertion rate. A total of 31 field duplicates were analysed alongside the routine samples. The statistical reproducibility of these field duplicates confirmed precision in sampling and crushing. To independently validate the primary laboratory’s performance, a subset of 20 representative samples was dispatched to Cotecna-AGS (ID: CL26-1904), an external laboratory. Cotecna-AGS performed a comprehensive 36-element suite (PR-01 V.00.) via Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Additionally, Cotecna-AGS analysed Ag, Cu, Zn, and Sb using Atomic Absorption (AA) following a 4-acid digestion (PR-19 V.00 DT-AAS 2g/100ml).

Resolution of Analytical Bias:

A comparative analysis between the primary laboratory (GCM) and the certified external lab (Cotecna-AGS) initially revealed a significant discrepancy in Silver {Ag} values, attributable to GCM’s use of aqua regia digestion compared to Cotecna’s 4-acid digestion.

To address this, GCM’s analytical protocol was updated to adopt the 4-acid digestion method. Following implementation, a scatter plot comparison yielded a strong correlation, with a coefficient (R²) of 0.9884) and an average Relative Percent Difference (RPD) for silver of approximately 7%.

Subsequently all trench and chip-channel samples were re-analysed using the updated method to ensure consistency across the dataset. Based on the assay results , and a strong correlation with the external laboratory, the data are considered to demonstrate acceptable levels of both accuracy and precision for exploration purposes.

The correspondent QP considers the QAQC programs to meet industry standard practice at the time of completion and the results to be acceptable.

• The verification of significant intersections by either independent or alternative company personnel.
• The use of twinned holes.
• Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.
• Discuss any adjustment to assay data.

Independent verification was structurally achieved through the external umpire assay program. A subset of 20 representative samples was dispatched to the independent laboratory Cotecna-AGS. The comparison of their 4-acid digestion AA and ICP-OES results against the primary laboratory’s (GCM) data provided a blind, external validation of the mineralised intervals, successfully triggering the optimisation of the project’s silver assaying methodology.

No drilling campaigns have been conducted within the project area to date. Consequently, the concept of “twinned holes” is not applicable to this stage of exploration.

All primary field data, including trench coordinates, channel dimensions, sample IDs, structural orientations (strike/dip), and qualitative geological descriptions (lithology, alteration, sulphide percentages), were recorded directly in the field using standardized paper logging sheets.

Field notes were transcribed daily into a centralized electronic master spreadsheet. The Project Geologist cross-checked 100% of the digital data entries against the original physical logs and high-resolution trench photographs prior to database integration.

All primary field data, including trench coordinates, channel dimensions, sample IDs, structural orientations (strike/dip), and qualitative geological descriptions (lithology, alteration, sulphide percentages), were recorded directly in the field using standardized paper logging sheets and maps, and then manually logged into the database.

Laboratory assay certificates and the centralized master database are stored securely on a cloud-based database network. The designated database geologist manually integrates all laboratory assay results into this cloud system, performing comprehensive, multi-layered quality checks to eliminate typing mistakes and ensure absolute database integrity. An external check program of 20 samples sent to Cotecna-(AGS) (using a 4-acid digestion) yielded a correlation coefficient (R²) of 0.9884) in the scatter plot and reduced the average Relative Percent Difference (RPD) between the labs to 7%.
(See Cotecna (AGS) & GCM Lab- Ag 4H)

A total of 30 analytical duplicates (laboratory pulp duplicates) for gold (Au) and 50 duplicates for silver (Ag) were analysed. Duplicate assay results show a high degree of correlation, with coefficients of determination( R²) of 0.9998 for Au and R² = 0.9997 for Ag, indicating strong repeatability. Thompson-Howarth precision analysis indicates high analytical precision, with values of 96.06% for Au and 98.34% for Ag.
(See Au Analytical Duplicate, Ag analytical Duplicate
and Thompson-Howarth Precision vs Concentration
Au-Ag Analytical Duplicate)

Additionally, 33 coarse reject duplicates were analysed for gold (Au), demonstrating a high degree of correlation, with a coefficient of determination of (R²) of 0.9988), indicating good repeatability and consistency at the crushing stage. 
(See Au Mecanical Duplicate)

To monitor potential cross-contamination during sample preparation and analysis, coarse and pulp blanks were inserted into the sample stream. This included 46 blank analyses for gold (Au) and 12 for silver (Ag).

Results indicate that blank values were consistently below five times the lower limit of detection (LOD) (Au = 0.01 g/t; Ag = 1 g/t), suggesting no material contamination during sample preparation or analytical procedures.
(See Au Blank and Ag Blank)

Standard accuracy was rigorously evaluated by measuring the percentage of analytical values falling within the acceptable ±2 and ±3 standard deviation (σ) thresholds.

Certified reference materials STD-OXE-101 (34 analyses) and STD-IN-M639-328 (34 analyses) returned results entirely within the ±2σ and ±3σ limits, i indicating acceptable analytical accuracy and precision..
(See STD-OxE-101 Au and STD-IN-M639-328 Au)

For silver (Ag) standards, certified reference materials STD-322-158 (17 analyses), STD-IN-M126-47 (13 analyses), and STD-IN-M68-18 (10 analyses) were used. All standards returned results within acceptable industry tolerance limits, with approximately 92.5% of results falling within ±2σ and ±3σ control limits, indicating no significant analytical bias.
(See STD-322-158, STD-IN-M126-47 Ag and STD-IN-M68-18 Ag)

No mathematical adjustments, multipliers, or factoring were applied to any assay values; below-detection-limit results are strictly recorded as half the lower detection limit (e.g., <0.01 g/t Au is entered as 0.005 g/t Au) for statistical consistency.

The results of the QAQC program indicate that for Ag, it has a precision of 98% and an accuracy of 92.5%, and for Au, it has a precision of 96% and an accuracy of 99%.

• Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.
• Specification of the grid system used.
• Quality and adequacy of topographic control.

• Data spacing for reporting of Exploration Results.
• Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.
• Whether sample compositing has been applied.

The current data spacing and distribution are sufficient to establish a strong understanding of surface geological continuity, structural controls, and the initial grade distribution of the mineralisation. The tight sampling intervals within individual trenches clearly define the geometry and boundaries of the mineralised structures.

The current dataset serves as a high-quality foundation to define geometry and targets. Subsurface diamond core or reverse-circulation (RC) drilling campaigns will be required in future phases to confirm the depth extension of the mineralisation and to provide the 3D data density necessary for formal resource estimation procedures.

No sample compositing has been applied to the primary assay data.

• Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.
• If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.

The project is currently in the surface geochemistry stage; no drilling campaigns have been conducted to date. The perpendicular orientation of the surface channel sampling guarantees that no material sampling bias has been introduced to the reported results.

• The measures taken to ensure sample security.

Collected material was immediately placed into high-density plastic sample bags, tagged with unique sample numbers, and securely sealed with single-use, tamper-evident plastic zip ties.

Sealed bags were transported directly from the field site to the certified laboratory (GCM) using company-owned vehicles driven by authorized staff. Upon arrival, the laboratory verified that all security seals were intact and officially logged the samples into their tracking system. No security breaches or tampering incidents were recorded.
Assay receipt was electronic and restricted to authorized personnel.

• The results of any audits or reviews of sampling techniques and data.

The database and current sampling methodologies are managed under internal peer reviews and standard operating procedures enforced by the project’s technical team.

• Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings.
• The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.

• Acknowledgment and appraisal of exploration by other parties.

• Deposit type, geological setting and style of mineralisation.

• A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:
  • easting and northing of the drill hole collar
  • elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar
  • dip and azimuth of the hole
  • down hole length and interception depth
  • hole length.
• If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.

• In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated.
• Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail.
• The assumptions used for any reporting of metal equivalent values should be clearly stated.

• These relationships are particularly important in the reporting of Exploration Results.
• If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.
• If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg ‘down hole length, true width not known’).

• Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.

• Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.

• Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples – size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.

• The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling).
• Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.