Historic gold mining between 1880-1920 occurred over a greater than 11 km trend where total production is reported as 41,000 oz gold at a grade of 33 g/t gold. Drilling during 1990-2000s focused on shallow, previously mined surface workings, covering an area of 100 m in width, 800 m length but only to 80 m depth.  As such, the entire field remains open along strike and to depth.  

Mineralization at the Sunday Creek Project is hosted in late-Silurian to early-Devonian-aged shales and siltstones containing a series of dykes of felsic-intermediate composition. Gold is concentrated mainly in and around the EW to NE-SW trending felsic dykes, within predominately NW oriented brittle multiple sheeted veins and cataclastic zones. Individual high-grade quartz-stibnite veins at Apollo and Golden Dyke, and cataclastic zones at Gladys were the focus of historical mining at Sunday Creek. These zones have been proven to continue to depth by SXGC. Broader vein-hosted and cataclastic mineralization grading less than 15 g/t gold appears untouched by the historic miners.

To February 28, 2025, a total of 188 drill holes for 76,265 m have been reported at the main Sunday Creek area along the 1,350 m strike between Christina and Apollo and regionally at the Leviathan, Tonstal and Consols prospects up to 8 km to the northeast of the main drill area.

Gold and antimony form in a relay of vein sets that cut across a steeply dipping zone of intensely altered rocks (the “host”). When observed from above, the host resembles the side rails of a ladder, where the sub-vertical mineralized vein sets are the rungs that extend from surface to depth. At Apollo and Rising Sun these individual ‘rungs’ have been defined over 600 m depth extent from surface to over 1,100 m below surface, are 2.5 m to 3.5 m wide (median widths) (and up to 10 m), and 20 m to 100 m in strike.

Our systematic drill program is strategically targeting these significant vein formations, initially these have been defined over 1,350m strike of the host from Christina to Apollo prospects, of which approximately 620 m has been more intensively drill tested (Rising Sun to Apollo). At least 70 ‘rungs’ have been discovered to date, defined by high-grade intercepts up to 7,330 g/t Au along with lower grade edges. Ongoing step-out drilling is aiming to uncover the potential extent of this mineralized system.

Sunday Creek – Additional exploration work

In October 2023, predecessor Southern Cross Gold Ltd ("SXG") released the results of first ever drill campaign at the Leviathan, Consols and Tonstal historic mining areas, located 5.0 km, 6.9 km and 7.9 km along strike respectively from the most westerly end of main project area with 12 diamond drill holes for 2,383 m. 

Mineralization at each location is the style same as the Sunday Creek main zone with disseminated arsenopyrite and pyrite mineralization in NW-oriented veins that cut across a steeply dipping zone of intensely bleached, sericite albitic siltstones, and sericite-carbonate-albite altered dyke rocks (the “host”).

Results included 0.5 m @ 15.7 g/t Au from 87.0 m in SDDLV003 and 0.3 m @ 19.4 g/t Au from 100.7 m in SDLV004.

The results suggest further high grades at depth remain to be found and SXG will return to its regional exploration program in the future.

Sunday Creek regional plan view showing soil sampling, structural framework, regional historic epizonal gold mining areas and broad regional areas tested by 12 holes for 2,383 m drill program. The regional drill areas are at Tonstal, Consols and Leviathan located 4,000 m to 7,500 m along strike from the main drill area at Golden Dyke- Apollo.

exploration target

In March 2025 SXGC released an updated Exploration Target to demonstrate the scale and high-grade gold-antimony potential of the Sunday Creek project as it progresses on the pathway to a resource. We plan to release a further update of the Exploration Target towards the end of calendar year 2025 to take into account continual drill results at the project.

The Exploration Target covers 67% of the strike of the core 1.5 km main drill area. The other portion of the main drill area has not been drilled to the intensity required to include in this Exploration Target, highlighting the potential to further increase the overall gold-antimony endowment of the Sunday Creek gold-antimony project.  This target area represents <10% of the 12 km strike of the dyke host across the project.

The approximate combined Exploration Target ranges are listed in Table 1, while Table 2 provides a summary of the Exploration Targets for each prospect. The location is shown in the figure below.

Table 1. Sunday Creek Exploration Target for Apollo, Rising Sun, Golden Dyke at the Sunday Creek Project

MARCH 2025 EXPLORATION TARGET

Click here for a detailed description of the Exploration Target

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grade continuity

In January 2024, SXG released a geological update with an outline of vein morphology and continuity. It was released to describe vein morphology and geological and vein continuity to provide geological context for the above Exploration Target.

The update demonstrated continuity of vein sets and grades in three dimensions across multiple datasets including:

• Structural oriented drill core data, quality control data and geostatistics that demonstrate a low coefficient of variation;
• Geological likeness;
• Predictability of extension drilling.
• Fifty years of historic mining records and drilled continuity below mined areas.

As of 31 December 2024, a total of 67 mineralized vein set shapes have been created for Sunday Creek. Gold and antimony form in a relay of vein sets that cut across a steeply dipping zone of intensely altered rocks (the “host”). These vein sets are like a “Golden Ladder” structure where the main host extends between the side rails deep into the earth, with multiple cross-cutting vein sets that host the gold forming the rungs.  At Apollo and Rising Sun these individual ‘rungs’ have been defined over 600 m depth extent from surface to over 1,100 m below surface, are 2.5 m to 3.5 m wide (median widths) (and up to 10 m), and 20 m to 100 m in strike.

Coefficient of variation

The figure above illustrates how gold grade capping (top-cuts or “TC”) affects both the average grade of composites in the Exploration Target and the statistical reliability of these sample populations. Lower coefficient of variation (CV) values — calculated as standard deviation divided over mean — indicate reduced geological risk through more consistent sample data.

The Sunday Creek project demonstrates favourable statistical characteristics across all zones:

• Rising Sun: CV decreased from 1.8 (before top-cutting) to 1.35 (after top-cutting
• Apollo: CV reduced from 1.36 (before top-cutting) to 1.0 (after top-cutting)
• Golden Dyke: CV remained stable at 1.0 (both before and after top-cutting)

Importantly, as drilling has progressed and high-grade core sub-domains have been identified, Sunday Creek has shown consistent decreases in CV values both before and after applying top-cuts, indicating improving data reliability and reduced uncertainty.

The estimated true widths of Rising Sun, Apollo, and Golden Dyke are relatively consistent across all prospects. Apollo has the largest estimated true width, averaging 4.2 m (median 3.5 m), Rising Sun at 2.8 m (median 2.4 m), and Golden Dyke at 3.2 m (median 2.3 m). Within the centre of many vein sets high-grade cores show consistency, with Apollo averaging 0.5 m (median 0.4 m, maximum 1.3 m) and Rising Sun averaging 0.6 m (median 0.4 m, maximum 2.4 m).

Metallurgy

Stage 1: Sighter Tests - Proving the Concept

The metallurgical journey at Sunday Creek began with initial sighter testing conducted on two drill holes from the project reported in January 11 2024. This work demonstrated that the mineralization responded well to standard gravity recovery and selective flotation processing, producing high recovery of both gold and antimony to separate high value concentrates.

The initial program successfully outlined an indicative flow sheet for Sunday Creek consisting of gravity separation of gold, followed by bulk or sequential flotation of gold and sulphides. This resulted in high recoveries of both gold and antimony into products that were anticipated to be readily saleable, while also highlighting the non-refractory nature of native gold at Sunday Creek with a high proportion of native ('free') gold in both test samples, with 84.0% in the RS01 sample and 82.1% in the AP01 sample.

The initial results were highly encouraging, achieving total gold recovery of 93.3% to 97.6% across three separate products, with primary antimony recovery of 89.5% to 94.3% in antimony concentrates. The samples also demonstrated high cyanide solubility of gold at moderate grind size (74.8% to 68.4%) and effective gravity recovery of 18% to 33% to high-grade concentrates ranging from 185 to 1,090 g/t Au.

Stage 2: Development - The Significant Development

Building on the initial sighter test results, the development team embarked on a Stage 2 program designed to investigate three critical areas: 1) gravity recovery optimization with upgrading of rougher products, 2) flotation enhancement using a range of chemical conditions and specialized collectors to improve selectivity between sulphide minerals in the antimony flotation stage while maintaining high overall gold recovery, and 3) advanced processing of flotation concentrates to assess the metallurgical response of contained gold.

The dataset examined included 66 mineralized intersections from the Apollo prospect and 74 from the Rising Sun prospect, providing a robust foundation for understanding metallurgical variability across the deposit.  Two bulk samples were prepared from selected drill core intersections to enable preliminary evaluation of spatial and mineralogical composition variability across the main project zones.

The Apollo composite (AP02) comprised 46.0 kg of material grading 4.84 g/t Au, 1.33% Sb, and 0.17% As. The Rising Sun composite (RS02) totalled 49.0 kg with grades of 5.83 g/t Au, 0.73% Sb, and 0.33% As. A Rising Sun Deep composite (RS03) representing the deeper, higher-grade zones with 32.5 kg of material grading 21.8 g/t Au, 0.24% Sb, and 0.25% As was selected for testing with the enhanced processing strategy and conditions. Further data from RS03 will be presented when results become available.

Current Significant Achievement

This work centres on the successful development of selective flotation conditions using specialized collectors that effectively separate stibnite (antimony sulphide) from arsenopyrite and pyrite, addressing a general challenge for antimony-gold projects globally. This work was conducted at the ALS Burnie Laboratory, Tasmania. Recent test work using selective flotation methodology achieved positive results (Table 1) through single rougher plus cleaner flotation stages. The results demonstrate an improvement in both recovery and selectivity compared to initial testing.

Table 1: Rougher-Cleaner Concentrate Assays (Post gravity extraction)

The gold grade of the concentrate reflects the interplay between the proportion of feed gold associated with arsenic-iron sulphides, the ratio of gold to antimony in the feed, the gold recovered to the metallic gold product, and the flotation rate of gold in the first flotation stage.

Converting these concentrate assays to representative mineral percentages (Table 2) reveals the purity achieved through the process:

Table 2: Mineral Composition Analysis

Performance Metrics - Validation of Success

Antimony recovery to concentrate ranged from 83.2% to 92.7% depending on feed type, while achieving antimony concentrate arsenic grades of 0.1% to 0.2%, significantly below the 0.6% thresholds typically required by antimony smelters.

The process consistently produces antimony concentrate grades up to 53.1% with gold grades in antimony concentrate reaching up to 93.2 g/t, while maintaining overall gold recovery of 91.8% to 95.6% across the three product streams.

Strategic Processing Framework

The development work has established a sophisticated three-product processing strategy that maximizes value recovery through complementary extraction methods (Table 3).

• The first product stream focuses on gravity metallic gold concentrate, achieving direct recovery of native gold representing up to 51.4% of feed gold to high-grade concentrates with minimal processing requirements.
• The second and most significant development involves the antimony-gold concentrate, producing high-grade concentrates up to 53.1% Sb with low arsenic content below 0.2% As. These concentrates are potentially highly marketable to antimony smelters and could offer excellent potential payabilities.
• The third product stream captures remaining free gold and gold associated with pyrite-arsenopyrite in a marketable and leachable sulphide concentrate, ensuring high overall gold recovery is maintained across the entire process.

Table 3: Gold Distribution Across Products

Comprehensive Testing Methodology

The success of this work resulted from a comprehensive testing program that included diagnostic LeachWELL testing, gravity recovery optimization, timed flotation with chemical condition variations, two-stage bulk rougher flotation with separate cleaning stages, gravity testing of concentrates, and cyanide solubility analysis. Quarter core samples were crushed, homogenised and split for analysis at ALS Burnie Laboratory, with diagnostic cyanide leaching conducted alongside gravity recovery using Knelson concentrator technology with Mozley Panner upgrade and extensive flotation testing with staged reagent additions.

Future Development Pathway

The results demonstrate significant scope for further optimization through additional cleaning stages to remove non-sulphide gangue, multi-stage cleaning optimization, locked-cycle testing for overall recovery confirmation, and process recycling optimization. Future testing will focus on understanding the effect of grind size on recoveries, understanding gold-rich/lower antimony grades within deeper mineralization, and creating geometallurgical models across deposit zones.

This milestone relates to laboratory-based test work and does not involve any changes to site activities. Southern Cross Gold remains committed to ongoing consultation and transparency with our local community as the project advances through study phases.

Freehold land acquisition

In May 2022, SXG completed the acquisition of 132 ha of freehold land that forms the key portion in and around the drilled area at Sunday Creek.  It subsequently purchased a further 0.65 ha in July 2023 that is located adjacent to both the main access and existing freehold ownership at the project.  

In December 2024, SXG completed a further deal to acquire an additional 1,054.5 ha of freehold land that directly surrounds the Sunday Creek project that is critical for securing future pathways for the project through securing future surface access and locating critical mine development infrastructure in an unpopulated zone to the south of the main drill area.

We may consider in the future other uses for the freehold land, such as renewable energy options, livestock grazing or agistment to help maintain the property although there are no current plans for such additional uses.  

To find out the latest details of our latest activities at Sunday Creek please refer to our announcements and presentations.

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