The Sunday Creek Project is a shallow orogenic (or epizonal) Fosterville-style deposit located approximately 60 km north of Melbourne and contained within 19,385 ha of both granted exploration licences and one granted retention licence.
Southern Cross Gold owns 133.29 ha of freehold land at Sunday Creek that form the key portion in and around the main drilled area at the project.
Sunday Creek at a glance
Location
60 km north of Melbourne
SXG ownership
100%
Number of holes reported by SXG to 16 October 2024
134
Tenements
EL 6163; EL 7232; RL 6040
Select drill results
Hole SDDSC107
455.3 m @ 7.2 g/t Au (uncut) from 413.6 m
Hole SDDSC077B
404.4 m @ 5.1 g/t Au (uncut) from 374.0 m
Hole SDDSC082
331.5 m @ 6.8 g/t Au (uncut) from 413.6 m
Hole SDDSC091
20.0 m @ 62.7 g/t Au from 430.0 m
The main historic workings at the Sunday Creek Project have been drill tested with encouraging results and remain open at depth and along strike.
Location diagram for 100 % Southern Cross Gold owned Sunday Creek project including the granted exploration permits and retention licence RL 6040. WGS84 map projection.
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.
Mineralisation 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 SXG. Broader vein-hosted and cataclastic mineralisation grading less than 15 g/t gold appears untouched by the historic miners.
To 31 May 2024, a total of 120 drillholes for 52,435 m have been reported at the main Sunday Creek area along the 1,200 m strike between Golden Dyke and Apollo and regionally at the Leviathan, Tontal 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 mineralised vein sets are the rungs that extend from surface to depth. At Apollo and Rising Sun these individual ‘rungs’ have been defined over 350 m depth extent from surface to 550 m below surface, are 10 m to 20 m wide, 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 1,350 m 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 62 ‘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 mineralised system.
To 31 May 2024, there are 47 individual intersections exceeding 50 AuEq g/t x m (“AuEq g/t x width in m”) and 38 individual intersections exceeding 100 AuEq g/t x m which are globally leading hit rates.
Assays from all completed holes have been released and can be found through our announcements here and below is a summary of the 10 best intersections reported so far.
Intersections are reported with a lower cut of 1.0 g/t AuEq cutoff over a maximum of 2.0 m with higher grades reported with a 5 g/t AuEq cut over a maximum of 1.0 m. The equation used for AuEq is AuEq=Au+Sb/1.58 and is based on forecast long term USD prices of Sb $8,500/tonne and Au$1,700/oz.
Sunday Creek longitudinal section across A-B in the plane of the dyke breccia/altered sediment host looking towards the north (striking 236 degrees) showing mineralised vein sets.
Sunday Creek plan view showing a selection of drillholes for results reported to 31 May 2024.
Trenching work has been performed for 200 m east of the drilled area at the Apollo prospect. Trench 1 intersected 14.0 m at 11.5 g/t gold and 0.3% antimony including 8.0 m @ 19.6 g/t gold and 0.4% antimony; Trench 2 intersected 2 m @ 4.9 g/t gold and 0.2% antimony.
In October 2023, 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 2,367m.
Mineralisation at each location is the style same as the Sunday Creek main zone with disseminated arsenopyrite and pyrite mineralisation 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 LiDAR, soil sampling, structural framework, regional historic epizonal gold mining areas and broad regional areas (Tonstal, Consols and Leviathan).
In January 2024 SXG released an Exploration Target to demonstrate the scale and high-grade gold-antimony potential of the Sunday Creek Project as a first step in the pathway to a resource.
The Exploration Target for the Sunday Creek project covers only 620 m or about 50% of the known strike of the main drill area and encompasses the Rising Sun and Apollo areas. This target area represents <10%of the 11 km strike of the dyke host across the project.
The estimated range of potential mineralisation for the Exploration Target is:
4.4 - 5.1 million tonnes grading at 7.2g/t AuEq to 9.7 g/t AuEq for 1.0Moz AuEq to 1.6Moz AuEq
The potential quantity and grade of the Exploration Target is conceptual in nature and therefore is an approximation. There has been insufficient exploration to estimate a Mineral Resource and itis uncertain if further exploration will result in the estimation of a Mineral Resource. The Exploration Target has been prepared and reported in accordance with the 2012 edition of the JORC Code.
Sunday Creek Exploration Target for Apollo and Rising Sun at the Sunday Creek Project
The Exploration Target is the first early opportunity to demonstrate the scale and high-grade potential as suggested by the successful drilling program undertaken at Sunday Creek. It was constrained to the drill footprint at Apollo and Rising Sun as they contained sufficient drilling to determine continuity and infer grade ranges. It represents approximately half the strike of the main drill area and significant potential exists to increase the size of the exploration target with high grade drill results beyond the Exploration Target area.
Click here for a detailed description of the Exploration Target
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:
A total of 42 mineralised vein set shapes were created for Sunday Creek. The mineralised vein sets are typically between 5-30 m wide, 20-100 m in strike and are defined vertically down to 1 km depth and up to 570m in depth extent on an individual vein set basis.
Coefficient of variation
The coefficient of variation (“CV”) is the ratio of the standard deviation to the average of the assay results. The lower the CV, the less variable and erratic the distribution of the mineralisation is, and therefore it is easier to model.
At Apollo, where sufficient drill density and drill spacing is present, geostatistical assessment provides validity of the geological shapes. Within Apollo, the average of all the vein sets has a CV below 1.5 when applied to 1 m composite data and an average CV of less than 2 for raw assays. Rising Sun requires further drilling before similar calculations can be made. The CV at Apollo implies both a strong understanding of the geological controls on mineralisation, correct sub-domaining of high tenor material and the predictability of high-grade mineralisation within these shapes.
Qualitative description of the range of the Coefficient of Variation (“CV”) within mineral systems. The lower the CV, the less variable and erratic the distribution of the mineralisation is, and therefore it is easier to model.
Click here for a detailed description of the continuity of vein sets and grades.
In January 2024, SXG released the results of its successful initial metallurgical test program conducted on two drill holes from Sunday Creek.
The initial program was successful in outlining a robust flow sheet for Sunday Creek. The proposed flow sheet consists of gravity separation of gold, followed by bulk or sequential flotation of gold and sulphides, that resulted in high recoveries of both gold and antimony into products that are anticipated to be readily saleable, with high returns for both gold and antimony values. The test work also highlighted the nonrefractory nature of native gold at Sunday Creek.
Recovery by gravity separation and flotation resulted in high recoveries of antimony and gold into two separate gold-sulphide concentrates that are anticipated to be readily saleable, with high returns for both gold and antimony values.
Samples selected for metallurgical test work.
Click here for a detailed description of the initial metallurgical test program at Sunday Creek.
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. We 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. We believe owning the freehold land better secures future surface access. 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 ASX announcements and presentations.