The Rockford Project is located within the highly prospective Fraser Range district of Western Australia, with tenure covering a total area of 2,993km2. Exploration is primarily focussed on magmatic nickel-copper-cobalt (Nova-Bollinger/Voisey’s Bay style), along with volcanogenic massive sulphide (VMS) style zinc-copper-silver and Tropicana style structurally controlled gold mineralisation.
The Rockford Project comprises 14 granted exploration licences with a detailed breakdown of ownership, area and manager given below:
- Legend (100%) 206km2;
- Legend (70%)/Creasy Group (30%) Three joint ventures (JV) covering 2,191km2 with Legend manager;
- IGO (60%)/Creasy Group (30%)/Legend (10% free carry) JV covering 634km2 with IGO manager;
- IGO (70%)/Legend (30% free carry) JV covering 24km2 with IGO manager
In 2015 Legend acquired an extensive exploration dataset over the entire Rockford Project, which is constantly being added to by Legend’s activities and reinterpreted/interrogated to identify specific areas for follow up exploration. These high-quality datasets include:
- Project wide high resolution aeromagnetic data at 50m line spacing
- Detailed gravity data over an 800m/400m x 100m grid, comprising 35,600 stations
- Aircore drilling with multi-element analysis of bottom-of-hole samples
- Detailed petrological descriptions of bottom-of-hole aircore samples
- Project wide soil and calcrete geochemical sampling over an 800m x 400m grid.
Exploration activities completed by Legend over the Rockford Project since the commencement of the JV on 23 September 2015 include:
- 6.5km2 3D seismic data acquisition, processing, and modelling
- Octagonal +24km2 3D seismic survey
- Project-wide geophysical data interpretation
- 3D inversion modelling of the aeromagnetic and gravity data
- Moving loop electromagnetic surveys selected target areas
- Fixed loop electromagnetic surveys over selected target areas
- Target ranking and evaluation
- Ongoing reconnaissance and infill Aircore drilling to generate and advance exploration targets
- RC and Diamond Drilling of geochemical and geophysical targets generated on prospect scale
- Mawson Ni-Cu-Co Discovery December 2019
- Mawson model Mineral Resource Estimate February 2023
Exploration results to date by Legend have highlighted seven priority prospects. These include magmatic nickel-copper sulphide style targets at Mawson, Octagonal, Magnus, Hurley, and Crean and VMS/VHMS style zinc-copper-silver targets at Shackleton and Worsley.
The initial and continued discovery of massive nickel-copper sulphide at Mawson confirms the prospectivity of not only the Mawson Prospect, but the 96km2 Mawson Intrusive Complex, and the greater >3000km2 of the Rockford Project area.
Legend achieved a watershed milestone in December 2019 at the Mawson prospect at its Fraser Range Rockford Project with the discovery of massive nickel-copper sulphides.
Subsequent diamond and RC drilling has identified extensions of nickel-copper sulphide mineralisation in all directions from the discovery hole RKDD007.
6.5km2 3D seismic data acquisition, processing and modelling.
Mineral Resource Estimate 2023
(See image gallery for results to date)
For further information, including latest assay results, please see the ASX Announcements.
Meanwhile the regional aircore, innovative moving loop EM surveys, and detailed gravity surveys will be ongoing throughout the project area to generate the next targets of the Rockford Project.
Legend is continuing a disciplined, systematic approach to the detection of identified mineralisation and evaluation of targets across the Rockford Project.
Ongoing and planned activities include:
- Aircore drilling – is completed across all generated targets at Rockford as a primary geochemical and lithological identification tool. Prospective targets are infilled with closer-spaced aircore drilling (in conjunction with ground EM) prior to commissioning of deeper RC and or diamond drilling
- EM Geophysics – MLTEM and FLTEM is undertaken across all identified targets across Rockford. DHTEM continues to play a key role in identifying potential extensions and new Ni-Cu mineralised zones at the mineralised prospects of Mawson and Octagonal. DHTEM is completed on all RC and diamond drillholes.
- Diamond Drilling – Used to target interpreted Ni-Cu mineralisation, DHTEM targets at depths below 300m, and structural and geological targets generated from previous RC and diamond drilling.
- RC Drilling – where applicable, RC drilling is a cost-effective tool designed to systematically evaluate aircore geochemical targets into primary rock, shallow MLTEM, FLTEM, and DHTEM targets, and geological targets generated
- Metallurgy – Preliminary metallurgical test work carried out at Mawson
- Seismic Survey – acquisition of 3D seismic data for advanced prospects for cost-effective drill target generation below 500m
- Environmental Studies – A Level 1 Flora & Fauna Survey has been completed at Mawson