Summary:
The Katanning Gold Project (KGP) gold mineralisation is localised along its eastern boundary by a regionally significant NNWstriking thrust fault bounded block, which extends over at least 17km of strike length. Thrust faults also define the eastern and western boundaries of the KGP internally, and these thrust-bounded blocks localise gold mineralisation zones as defined by laterally continuous mineralised lodes within the Central and Southern Zones. These mineralised lodes, from east to west are named Jinkas, White Dam and Jackson–Dingo.
Within the Central Zone the Jinkas and White Dam lodes are folded around a quartz monzonite sill, with Jinkas located in the hanging wall of the sill and White Dam in the footwall. The Jinkas and White Dam lodes are the most significant lodes in terms of contained ounces at the KGP. The quartz monzonite forms the core of a major tight NNW-plunging synform, extending over a 5,000m strike length of the Central Zone. Jackson is located proximal to the footwall granite, west of the JinkasWhite Dam lodes.
Within the Southern Zone, the Dingo lode is the primary lode, situated proximal to a footwall granite, and is interpreted to be the southern continuation of the Jackson lode in the Central Lode.
Within the Northern Zone, the Datatine lodes are differentiated from the lodes of the Central and Southern Zones as they are ENE-striking, due to being re-oriented along a major ENE-striking thrust fault. Datatine lodes are proximal to a footwall granite, located to the NNW.
Across the entirety of the KGP, high-grade zones are focussed within fold hinge zones of tightly folded and metamorphosed rocks. These high-grade zones plunge broadly NNW in the Central Zone, SSE in the Southern Zone, and to the ENE at Datatine in the Northern Zone.
All mineralised lodes at the KGP are parallel to the primary gneissic foliation and display exceptional continuity along strike and down-dip. Confidence in the geological interpretation is high, with mineralisation being correlated between drill holes and between drill sections. Ausgold geologists interpreted 0.3g/t Au mineralisation on cross-sections, which guided the creation of a wireframe model. Ausgold geologists have also modelled the quartz monzonite, post mineralisation dykes (solid waste domains) and significant weathering horizons.
Gold mineralisation is hosted by medium- to coarse-grained mafic gneisses that dip at approximately 30° to 45° towards the northeast in the Southern Zone and Central Zone and approximately 40° to 50° towards the south-southeast in the Northern Zone. These units represent Archaean greenstones metamorphosed to granulite facies.
The mineralised gneissic units are interlayered with barren quartz-monzonite sills up to approximately 120 m thick and are cross-cut by several Proterozoic dolerite dykes that post-date mineralisation and granulite metamorphism.
Gold predominantly occurs as free gold associated with disseminated pyrrhotite and magnetite, lesser pyrite and chalcopyrite and traces of molybdenite.
Below is a detailed description of mineralised lodes at the KGP.
Jinkas-White Dam: The Jinkas and White Dam lodes are folded around a quartz monzonite sill.
Jinkas and White Dam collectively have 44 defined sub-parallel lodes, striking towards the NNW and dipping at approximately 35 to the ENE. The lodes consist of a defined strike length of approximately 3,000m, dip extents ranging from 50 to 560m and an average lode thickness of between 3 and 5m. The lodes have been interpreted to the surface and to a depth of up to 370m vertically. The modelling connects the Jinkas lodes to the White Dam footwall lodes through the thickened synformal fold hinge position referred to as Jinkas South, which extends over a strike length of approximately 2,300m.
Olympia: The Olympia lodes represent the northern-most continuation of the Jinkas lode, in a location where grade increases near-surface. Olympia comprises of 25 mineralised lodes, striking towards the NNW dipping at approximately 35" to the ENE. The lodes consist of a defined strike length of approximately 2,200m, dip extents ranging from 50 to 440m and average between 2 and 3m thickness. The lodes have been interpreted to the surface and to a depth of up to 210m vertically. Olympia mineralisation remains open along strike to the north and down-dip.
Jackson: Jackson comprises of 43 sub-parallel lodes striking towards the NNW and dipping at approximately 30" to the ENE. The lodes consist of a defined strike length of approximately 5,200m, dip extents ranging from 50 to 800m and an average lode thickness of 3m. The lodes have been interpreted to the surface and to a depth of up to 415m vertically.
Dingo: Dingo comprises of 35 sub-parallel lodes striking towards the NNW and dipping at approximately 35" to the ENE. The lodes consist of a defined strike length of approximately 2,900m, dip extents ranging from 50 to 420m and average lode thickness of between 2 and 3m. The lodes have been interpreted to the surface and to a depth of up to 270m vertically. Dingo mineralisation remains open along strike to the north and down-dip.
Datatine: The Datatine deposit estimates were first reported in the 2018 Resource upgrade and remain unchanged until this estimate. Datatine comprises of 14 sub-parallel lodes striking towards the ENE and dipping at between 40-50° to the SSE. The lodes consist of a defined strike length of approximately 550m, dip extents ranging from 100 to 290m and an average lode thickness of between 3 and 5m. The lodes have been interpreted to the surface and to a depth of up to 400m vertically. Datatine mineralisation remains open along strike to the ENE and down-dip.