Legend Mining Limited (ASX:LEG) has started regional exploration over the northwest part of the Rockford Project in Western Australia’s Fraser Range.
This work will comprise a combination of focused diamond drilling at Magnus and Octagonal prospects along with regional aircore drilling.
The new exploration program begins with diamond drilling at Magnus prospects with Octagonal to follow soon.
An aircore drilling program has also commenced over western regional targets testing aeromagnetic, gravity and geochemical targets.
“An exciting milestone”
Legend managing director Mark Wilson said: “The commencement of the regional program for this year is an exciting milestone for the Rockford Project.
“The diamond drilling at Magnus will be the first-ever into the Magnus intrusion and will be the first diamond drilling by Legend at Octagonal.
“Octagonal is one of only four publicly disclosed massive nickel-copper sulphide occurrences in the Fraser Range.
“One of the diamond rigs at Mawson has been redeployed to this regional program, due to logistical issues around rig and staff availability.
“It is planned that this rig will move onto the Crean and Hurley prospects once Magnus and Octagonal drilling is completed.”
Diamond drilling is expected to take 4-6 weeks while aircore drilling is likely to take 5-6 weeks with results reported as they come to hand.
Regional exploration
The company has started regional exploration over tenements, E28/1716 and E28/1717, which contain the advanced Magnus and Octagonal prospects, both characterised by ‘eye’ shaped aeromagnetic features and the presence of highly favourable mafic/ultramafic intrusive host rocks.
Both prospects lie within the same NE-SW trending structural corridor that hosts the Silver Knight and Nova nickel-copper deposits some 110 kilometres and 150 kilometres to the southwest respectively.
After extensively reviewing previous geological, geophysical and drilling data over Magnus and Octagonal, the company has designed diamond drill holes to test a combination of geological and geophysical targets.
Legend also plans to drill more than 100 aircore holes for approximately 7,500 metres to test several aeromagnetic and gravity features interpreted to be mafic/ultramafic intrusives.
Magnus prospect
Magnus was originally targeted due to its distinctive ‘eye’ (4.5 kilometres x 1.2 kilometres) aeromagnetic character.
The diamond drilling marks the first drilling of the Magnus intrusion and two diamond holes totalling 800 metres have been designed to test elevated nickel-copper aircore results coincident with gravity highs over a known intrusion within the central part of the Magnus Intrusive Complex.
The second hole will be contingent on the visual results of the first diamond drill hole.
Aircore drilling will be undertaken over four areas targeting previous anomalous nickel-copper aircore results and a combination of aeromagnetic and gravity features.
Octagonal prospect
Like Magnus, Octagonal was also targeted due to its distinctive ‘eye’ (4 kilometres x 2 kilometres) aeromagnetic character, with initial soil sampling and aircore drilling returning anomalous nickel-copper values.
Aircore drilling over the aeromagnetic feature defined the Octagonal intrusive complex comprising highly favourable nickel-copper host rocks including olivine gabbronorite, troctolite, peridotite, gabbronorite and norite.
The mineralisation identified so far is discontinuous and sub-economic, however, demonstrates all the characteristics of a fertile magmatic nickel-copper sulphide system.
The company has designed two diamond drill holes totalling 1,000 metres on the eastern margin of the intrusive complex.
Aircore drilling will also be carried out over four areas targeting previous anomalous nickel-copper aircore results and a combination of aeromagnetic and gravity features.
Future programs
The company plans to undertake downhole electromagnetic (DHTEM) on all completed diamond drill holes at Magnus and Octagonal.
Following the completion of diamond drilling at Magnus and Octagonal, the rig will move south to test EM conductors at the Crean and Hurley prospects.
Legend will also move aircore rig south to test aeromagnetic and gravity targets.