Legend Mining Ltd (ASX:LEG) has made broad progress across its Rockford Project in the nickel-copper rich Fraser Range of Western Australia with a comprehensive regional exploration program.
The program involves diamond drilling at the Crean, Hurley and Northerly prospects, Moving Loop Transient Electromagnetic Surveying (MLTEM) at Northerly and 12,168 metres of regional aircore drilling across the entire Rockford Project.
Early Northerly success
"Our field team has done an exceptional job to execute these programs with the industry-wide labour difficulties being experienced under the current border travel restrictions,” Legend managing director Mark Wilson said.
“The early success from the new Northerly prospect is particularly pleasing with anomalous geochemistry indications from aircore, sulphides in intrusive host rocks observed in diamond drill core and a large shallow conductor from the MLTEM survey.
“The significance of all of these programs will be better understood once all assays and analysis of the results are collated.”
Technical discussion
The regional exploration program targeted the E28/1718, E28/1727 and E28/2404 tenements, housing the Crean, Northerly and Hurley prospects respectively. All three have been identified by Legend as favourable nickel-copper-cobalt targets through systemic exploration using aircore drilling and MLTEM surveys.
Crean and Hurley prospects lie within the same NE-SW trending structural corridor which hosts the Silver Knight and Nova Bollinger nickel-copper deposits to the south.
Completed diamond drilling has confirmed that Crean, Hurley, and Northerly are prospective orthomagmatic (crystallised mineralisation) nickel-copper intrusive hosts, akin to the known deposit hosts of Nova-Bollinger and Silver Knight in the Albany-Fraser Belt.
Additionally, data indicate large mafic and ultramafic (low silica formation) intrusions in all three tenements, with intersections of drill core containing variable amounts of disseminated and blebby pyrrhotite and chalcopyrite with fine graphite and magnetite also noted, suggesting contaminated intrusions.
These intrusions are interpreted to be prospective hosts for nickel-copper mineralisation.
Focused aircore drilling continues to develop the prospect pipeline across over 3,000 square kilometres at Rockford, with the aim of defining prospective mafic and ultramafic intrusive bodies which are likely to host economic nickel-copper mineralisation.
A total of 213 aircore holes for 12,168 metres have been drilled over ranked targets across the Rockford Project. Assay results for completed aircore drilling are pending, with current laboratory timeframe on receipt of results expected at seven to nine weeks.
MLTEM survey
A MLTEM survey across the greater Northerly prospect identified a large, shallow conductive feature west of the Northerly aircore target. The north-northwest orientation of the conductor is offset to the regional north-northeast geological strike, suggesting this is not a stratigraphic feature that was formed layer by layer over time from above.
The conductor also lies on the western margin of a gravity high. Additional MLTEM and Fixed Loop Transient Electromagnetic Surveying (FLTEM) is planned to close off or extend the current feature before initial aircore drill testing.
Future programs
Future work programs at Crean, Hurley and Northerly will include assessment of geological, geochemical, geophysical and structural results from completed diamond drilling, followed by planning of extensive aircore drilling, innovative MLTEM/FLTEM, and targeted diamond drilling.
These programs will be designed to define the target intrusion geometry at each prospect, as well as to identify and target mineralisation through systematic exploration, with the aim to discover multiple economic nickel-copper sulphide accumulations.
About the company
Legend Mining is an exploration company with a mission to make value-adding mineral discoveries and utilise all available asset bases to maximise shareholder benefit.
The company’s exploration focus is on its nickel-copper Rockford Project in the Fraser Range, Western Australia, with its joint venture partners and major shareholders Creasy Group and IGO Ltd.