Omega / PSI Prospects
The Omega North, Omega South and Psi deposits are located 44km north of the historic Gidgee mill. Access from the Gidgee mill is along an established haul road. The deposits have been mined historically by three open cuts and one underground operation (Omega South) over a combined strike length of ~700m.
The current MRE for the Psi deposit is 326,000t @ 1.81 g/t Au for 19,000oz. (refer to Horizon Gold Ltd ASX announcement dated 25 July 2022) (Figure 1).The Omega North and Omega South mineralisation is not in the current Gum Creek Mineral Resource Estimate.
Figure 1: Psi 3D view looking down to the north-west showing drill holes and OK block model coloured by Au (g/t)
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 (Figures 1 to 3). 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.
The crown pillar region just beneath the historic open pit at Omega South contains a number of significant shallow intercepts (>60 Au gram x metres) including:
- 12m @ 21.8g/t Au from 67.0m (GWRC088)
- 15m @ 5.7g/t Au from 58.0m (GWRC233)
- 23m @ 2.7g/t Au from 57.0m (GWRC274)
Significant intersections (>80 Au gram x metres) from the deeper parts of the Omega South deposit, that remain open down plunge of the underground stopes include:
- 30m @ 21.1g/t Au from 57.0m (OUD162)
- 13m @ 10.8g/t Au from 122.0m (OUD218)
- 24m @ 6.1g/t Au from 50.0m (OUD184)
- 10m @ 10.4g/t Au from 127.0m (OUD215)
- 14m @ 7.1g/t Au from 112.0m (OUD213)
- 22m @ 3.7g/t Au from 76.0m (OUD163)
Significant intercepts (>20 Au gram x metres) from immediately below the Omega North open pit include:
- 14.6m @ 3.3g/t Au from 80.5m (GWRC271)
- 15m @ 2.6g/t Au from 61.0m (GWRC031)
- 14m @ 2.0g/t Au from 46.0m (GWRC213)
- 6m @ 3.7g/t Au from 72.0m (GWRC271)
Significant intersections (>40 Au gram x metres) from immediately below the base of the PSI open pit include:
- 5m @ 13.8g/t Au from 53.0m (GWRC408)
- 11m @ 6.1g/t Au from 34.0m (GWRC400)
- 13m @ 4.4g/t Au from 27.0m (PS698910)
- 16m @ 3.6g/t Au from 96.0m (GWRC504)
- 12m @ 4.1g/t Au from 38.0m (GWRC397)
- 12m @ 3.8g/t Au from 20.0m (GWRC376)
Refer to Horizon Gold Ltd ASX announcement dated 15 February 2021, “Gum Creek Geological Review”. CPs L.Ryan, M.Gunther, D.Archer.
Exploration drilling will focus on the target areas down-plunge of the better intercepts at Omega North and PSI with the aim of adding resources to the Gum Creek Gold Project MRE.
Figure 2: Omega – PSI long section showing gold intercept gram x metre pierce points, historic open pits, underground infrastructure, and interpreted high-grade ore shoots.
Figure 4: PSI Deposit cross section showing mineralised envelope, significant intercepts, and historic open pit.
Figure 5: Omega South, Omega North and PSI pits looking north.