Summary:
The Havieron deposit is hosted within two primary basement sedimentary units of the Puntapunta Formation; a thin planar biotite rich metasiltstone to meta-arenite, and a thickly bedded white to pale green calc silicate actinolite marble, both of which have been subject to low-grade regional metamorphism.
The deposit comprises an ovoid shaped zone with a series of nested vertically extensive breccia columns (the Breccia Pipe) that coalesce into a large volume of variable brecciation, alteration and sulphide mineralisation which trends northwest to southeast. Approximate dimensions of this pipe measure 650m in length by 350m in width and 1,400m in depth along a northwest orientation. The Breccia Pipe includes unmineralised to low-grade crackle breccia and a series of mineralised cemented breccias.
The breccia hosting the highest grade gold and copper mineralisation occurs on the southeast margins of the Breccia Pipe and is referred to as the South East Crescent (Crescent Zone). The Breccia Pipe also includes relatively small dioritic intrusions with brecciated contacts or wall rock clasts within the breccias. The Breccia Pipe is intruded by a 20–30m wide, north-northeast trending, steeply dipping post mineralisation dolerite dyke.
The Crescent Zone lies along the southeast margin of broader zone of hydrothermal carbonate-quartzsulphide-actinolite-biotite-cemented breccias, veins and replacements, defining an ovoid zone (800m x 500m) of calc-silicate alteration that is the footprint of Havieron.
The highest average grades of mineralisation is concentrated along the south-eastern edge of a complex of nested diorite intrusions emplaced into sedimentary host rocks. Higher grade zones are associated with increased sulphide concentrations, with sulphides including pyrrhotite, chalcopyrite and pyrite, commonly with quartz. Mineralisation has been observed to over 1,000m in vertical extent below the 420m of post mineralisation cover sequence.
Multiphase hydrothermal breccias at Havieron are classified on the dominant mineralogy of the breccia cement, based on variable proportions of actinolite, calcite and sulphide. A quartz-rich variant of the actinolite-cemented breccias also occurs. The hydrothermal breccias have a strong spatial association with the nested diorite intrusions.
Superior grades of gold (+2 g/t Au) and copper (+0.2% Cu) are typically associated with more rich sulphidebearing calcite-actinolite cemented breccia that in parts of the system transitions into the more massive sulphide mineralisation (i.e., the Crescent Zone). Still, higher gold grades (+5 g/t Au) can be found associated with the quartz-rich variant of the actinolite cemented breccia.
The Crescent Zone is a 5 - 40m wide zone of sulphide and quartz rich hydrothermal breccias and massive sulphide extending 700m in unfolded section from the basement contact and defined over 1,000m vertically, tapering to ~200m and open at that depth.
In 2023 drilling defined a new high-grade mineralised domain, referred to as the Link Zone. This zone is interpreted to encompass the high-grade core of what was previously referred to as the Eastern Breccia Zone. The Link Zone remains open at depth and to the north at depth (bounded by the Breccia Pipe).
Dimensions
Variable brecciation, alteration and sulphide mineralisation are observed with a footprint with dimensions of 650m x 350m trending in a north west orientation and over 1100m in vertical extent below ~420m of cover. The South East Crescent Zone Mineral Resource extents are ~550m in unfolded plan section, between 5-40m true width and 1200m in vertical extent, mineralisation remains open at depth.
The Link zone begins at approximately the 4000mRL (1250m below surface) and has been defined down to 3750mRL. The Link Zone is a moderately dipping approximately 30m wide by 200m long zone of mineralisation.
The Breccia Mineral Resource occurs as a 50-100m sleeve marginal to the South East Crescent Zone Mineral Resource and also with pockets within the greater breccia pipe. These pockets within the core of the breccia trend from the north west near the top of the system, downwards towards the north east in the lower levels of the system and potentially connect with the Eastern Breccia material.