Summary:
The Gum Creek consists Swan OC/UG, Swift OC/UG, Heron South OP, Howards OP, Specimen Well OP, Shiraz OP, Wilsons UG, Omega and PSI, Kingston Town, Eagle deposits.
Swan Trend
Gold mineralisation in the Swan area is associated with conjugate quartz-carbonate-pyrite vein sets preferentially hosted within carbonate-sericite altered dolerite. Conjugate vein sets are shallow southeast dipping with lodes generally plunging to the south (i.e. Australia, East and Albania Lodes) and moderate to steeply northeast dipping with lodes plunging to the north (i.e. Monte Carlo, Sicily, Tunisia, Cascade and Premium). High-grade ore shoots are parallel to vertical fold hinges within the dolerite and formed at conjugate vein set intersections and at the intersection of vein sets with the Butcherbird Shear Zone to the east. The vein sets, associated tension gashes and high-grade ore shoots have been subjected to later fault/shearing events resulting in localised orebody complexities.
The Swan Mineral Resource area is a large mineralised system with a strike length of 1.4km. The area retains excellent scope for potentially defining further shallow open cut and underground Mineral Resources beyond the previously mined and current resource area, particularly along strike to the north and down plunge on many of the Swan underground lodes including Monte Carlo, Monaco, East, Sicily, Tunisia, Cascade and Premium Lodes.
Swift Trend
Gold mineralisation in the Swift area is also associated with conjugate quartz-carbonate-pyrite vein sets preferentially hosted within carbonate-sericite altered dolerite. Conjugate vein sets are shallow southeast dipping with lodes generally plunging to the south, and moderate to steeply northeast dipping with lodes plunging to the north. High-grade ore shoots are formed parallel to vertical fold hinges within the dolerite, at conjugate vein set intersections and at the intersection of vein sets with the Swift Shear which runs through the eastern edge of the Swift open cut mine.
The Swift Mineral Resource area currently has a strike length of 1.1km and retains excellent potential for defining further shallow open cut and underground resources beyond the previous mining and current resource area, especially along strike to the north of the Gannet open pit, where shallow RC drilling has been planned and down plunge on several deeper high-grade lodes where diamond drilling is currently being designed.
Howards
The Howards deposit is located in the southern portion of the Gum Creek Greenstone Belt, 28km southeast of the historic Gidgee mill. The current MRE for the Howards deposit is 6.0Mt @ 1.1g/t Au for 204,000. The majority of the Howards deposit occurs within a north-south striking, steep west dipping shear zone that remains open at depth. The deposit is currently 1km in length and up to 50m wide. Gold mineralisation is associated with quartz veining and shearing within a biotite-silica altered basalt, located along the eastern contact of the Montague granodiorite.
Wilsons
Gold mineralisation occurs in three lodes hosted by sheared, strongly silica-carbonate-biotite-pyritearsenopyrite altered metasedimentary rocks in the footwall to the Wilsons dolerite. The three lodes, named from north to south Wilsons 1, Wilsons 2 and Wilsons 3, occur within a 700m section of the Wilsons Shear Zone and have individual strike lengths of ~120m, 100m and 80m respectively. The deposits have been mined historically by three open cuts to a depth of ~60m. The mineralisation has been drilled to vertical depths, below surface of 570m (Wilsons 1), 470m (Wilsons 2), and 450m (Wilsons 3) with widths varying between 2 and 15m.
Gold mineralisation in all three lodes plunge to the west-northwest and are open down-plunge, providing significant potential to increase the size of the MRE with further drilling. The current interpretation indicates the possibility for lodes 1 and 2 to coalesce at depth providing potential to increase the strike of the lode mineralisation. Repetition of high grade (>8g/t Au) domains within the plunging shoot geometries will be a high priority target for future drilling. There is also potential for repetition of the lodes along strike to the north and south.
Omega and PSI
The Omega North, Omega South and PSI deposits are located 44km north of the historic Gidgee mill. Access from the Gidgee mill is excellent along established haul roads and well-maintained gravel roads. The deposits have been mined historically by three open cuts and one underground operation (Omega South) over a combined strike length of ~700m. These deposits are not in the current Mineral Resource Estimate.
Gold mineralisation is hosted by folded Banded Iron Formation (BIF) displaying steep south to southeast plunging fold axes and corresponding gold lodes at Omega South and PSI, and steep north plunging fold axes and gold lodes at Omega North. High-grade plunging gold lodes correspond to the orientation of BIF thickening in fold hinges, dilational jogs, and the intersection of north-south trending sinistral faults and breccia zones.
Specimen Well
The deposit is currently just over 170m long, 5 to 25m wide and has not been previously mined. Gold mineralisation occurs in quartz veined, talc-tremolite-chlorite schist and quartz feldspar porphyry on a sheared mafic/sediment contact. Mineralisation strikes north-northeast, is sub-vertical to steeply west dipping, displays a steep south plunge, and remains open to the north and down plunge to the south.
Kingston Town
The Kingston Town deposit is located 20km south-southeast of the historic Gidgee mill and has been mined historically by open cut methods. The main mineralised lode is currently over 300m long, strikes north-south, dips steeply to the east and plunges to the south within the main Kingston Town Shear Zone. Gold mineralisation is associated with quartz-carbonate sulphide veining within a fine-medium grained quartz dolerite. This deposit is not in the Mineral Resource Estimate.
Heron South
The Heron South deposit is currently over 600m long and hosted by a north-south striking, steep easterly dipping shear zone within basalt and minor interflow sediments. Gold mineralisation is associated with quartz-carbonate-pyrite-arsenopyrite-pyrrhotite veining within strongly silica-sericitecarbonate altered basalt. High grade lodes display shallow to moderate north and shallow south plunges. The mineralisation remains open along strike to the north and south and at depth down dip and down plunge.
Eagle
The Eagle deposit is located in the main historic mining area just 1.4km south of the Gidgee mill. This deposit is not in the Mineral Resource Estimate. Gold mineralisation has a strike length of ~350m and is hosted within carbonate-sericite-pyrite altered dolerite in the hanging wall of the steeply west dipping Gidgee Shear Zone. Steep southerly plunging high-grade ore shoots that extend beneath the partially mined supergene mineralisation are interpreted to be controlled by an oblique dolerite/amygdaloidal basalt contact zone. The deposit retains excellent potential for defining shallow open cut and underground resources beyond the current open pit, particularly along strike to the north, south and down plunge to the south.