Rose Hill Drilling Results Confirm Open Pit Potential
- Reserve conversion infill drilling completed at the Rose Hill gold project in Coolgardie, 35km west of Kalgoorlie-Boulder in the Western Australian goldfields
- Drilling to date comprises 29 reverse circulation holes for 899m to a maximum depth of 65m
- Current Rose Hill Mineral Resource estimate to 300m depth stands at:
o 1.2Mt @ 2.49g/t Au for 95,000oz at a 0.7g/t lower cut-off grade
- Significant shallow high grade intercepts received include:
o 6m @ 2.73g/t Au from 0m (RHRC20039) and 7m @ 2.34g/t Au from 15m (RHRC20044)
o 5m @ 4.79g/t Au from 4m and 2m @ 3.12g/t Au from 24m (RHRC20031)
o 2m @ 1.93g/t Au from 11m and 15m @ 1.66g/t Au from 18m (RHRC20037)
o 7m @ 1.15g/t Au from 0m and 3m @ 6.63g/t Au from 10m (RHRC20013)
o 7m @ 2.36g/t Au from 2m (RHRC20020) and 10m @ 1.94g/t Au from 10m (RHRC20040)
- Results improved geological confidence within the mineralised envelope which will facilitate an updated resource model with improved JORC classification and maiden Ore Reserve
- Initial scoping work indicates the potential for an open pit development followed by decline development to access the higher grade underground lodes at depth
- Metallurgical test work completed with excellent overall gold recoveries of 92% - 96% with a high gravity recoverable gold component
- Updated resource model for Rose Hill expected in the current December Quarter 2020 with open pit and underground reserve studies underway as part of the Feasibility Study
Commenting on the Rose Hill results, Horizon Managing Director Mr Jon Price said:
"Rose Hill continues to demonstrate significant open cut and underground potential and we look forward to completion of the updated resource models and reserve generation studies in coming quarters as drilling continues with four rigs across a number of core project areas."
"The Company's aim is to generate additional high grade open pit and underground reserves supplementing the large scale baseload Boorara project in Kalgoorlie to underpin a longer term production pipeline and a standalone processing facility at Boorara."
Rose Hill is one of four core satellite gold projects being advanced to complement the baseload Boorara gold project as part of the consolidated Feasibility Study to deliver an initial five year mine plan and underpin the establishment of a stand-alone processing facility at the Boorara mine site. Trial mining at Boorara is complete and toll milling campaigns will continue through to January 2021. The aim is to have all core project resources updated in the December 2020 and March quarter 2021 enabling reserve generation in the June Quarter 2021.
During the September Quarter, the Company completed 29 infill RC holes at Rose Hill to a maximum depth of 65m. The aim of the drilling was to improve geological confidence near surface enabling improved JORC classification to the Measured and Indicated Category for reserve conversion.
Rose Hill Project Geology
Rose Hill is located 0.5km southeast of Coolgardie and lies on the western margin of the Archean Norseman-Menzies Greenstone Belt. Mineralisation is hosted within the main Rose Hill diorite (porphyry), adjacent to the hanging wall ultramafic and an eastern porphyry unit alongside the Greenmount Sill (Figure 2*). It is part of the same mafic-ultramafic package that includes Brilliant, Tindals and Dreadnought to the south and Queen of Sheba immediately to the north.
Rose Hill Drilling Summary
Gold mineralisation is found within a steep dipping, bleached dioritic porphyry host rock and is associated with thin stock work quartz veining and sulphides. Visible gold was observed in some of the drill core. There are variable abundances of biotite and garnet within the diorite that are typically associated with lower grades. Pyrite, pyrrhotite and arsenopyrite are the dominant sulphides.
The main purpose of the 29 hole program was to focus on the shallower and open pittable areas with a view to upgrade the Inferred and Indicated ore to the Measured and Indicated Categories. Many of the historic holes had composited data which was deemed to be inappropriate for mine planning purposes. Single meter assays provide a more standard approach in assisting the definition of Measured Resources.
The assays and grades were all within expectations and significant mineralisation was encountered at increased drill density. The bulk of the Rose Hill high grade (>4g/t Au) ore, indicated by Horizon's previous drill programs, occurs at depth (Figure 3-6*). Several holes were targeted close to the footwall contact to test for additional ore as returned in historic drilling, however most of these holes recorded low grade mineralisation. A list of significant assays is shown in the link below.
Brilliant North Update
The Brilliant North project lies 80m south of Rose Hill and is located on M15/1204. Horizon retains the mineral rights to the top 30m of this tenure. The Brilliant North orebody is believed to represent the southern extension of the Rose Hill deposit. Horizon feels there is considerable encouragement at Brilliant North given some of the historical intercepts as shown below.
- 16m @ 2.00g/t from the surface (1SBRC006) (Wamex Report A66135)
- 11m @ 2.44g/t Au from 21m (SB5) (Wamex Report A62255)
Horizon has delayed the planned resource drilling in 2020 at Brilliant North in order to focus on the emerging Coote prospect at Binduli. Drilling at Brilliant North is now planned in early 2021.
Further drilling is planned at Rose Hill and includes several RC and geotechnical diamond holes for optimal open pit design, portal location and underground development studies. Confirmatory metallurgical and processing testwork of the existing core will also be completed.
The updated Mineral Resources at Rose Hill and Brilliant North will form part of the consolidated Feasibility Study with the aim of generating a minimum five year mine plan underpinning the construction of a stand-alone processing plant at the Boorara mine site, 10km east of Kalgoorlie-Boulder.
Consistent with Horizon's Coolgardie strategy, the Company will undertake a more detailed assessment of the nearby Gunga leases (Figure 1) which contain several advanced prospects including the 60koz Gunga West deposit and Silverstar.
Core advanced projects under evaluation for reserve generation and the initial production profile includes the 507,000 ounce base load Boorara project where trial mining has commenced, the Binduli gold project area including the 74,000 ounce Crake discovery, the 289,000 ounce Teal gold camp, the Rose Hill and Brilliant North open cut and underground gold projects and the newly acquired Kalpini gold project where drilling is planned in the current December Quarter 2020.
*To view tables and figures, please visit:
About Horizon Minerals Limited
Horizon Minerals Limited (ASX:HRZ) is a gold exploration and mining company focussed on the Kalgoorlie and Menzies areas of Western Australia which are host to some of Australia's richest gold deposits. The Company is developing a mining pipeline of projects to generate cash and self-fund aggressive exploration, mine developments and further acquisitions. The Teal gold mine has been recently completed.
Horizon is aiming to significantly grow its JORC-Compliant Mineral Resources, complete definitive feasibility studies on core high grade open cut and underground projects and build a sustainable development pipeline.
Horizon has a number of joint ventures in place across multiple commodities and regions of Australia providing exposure to Vanadium, Copper, PGE's, Gold and Nickel/Cobalt. Our quality joint venture partners are earning in to our project areas by spending over $20 million over 5 years enabling focus on the gold business while maintaining upside leverage.
Horizon Minerals Limited