ASX-listed base metals and gold play, Si6 Metals, has taken the plunge at its flagship Maibele North nickel-copper project in Botswana with a diamond drill hole boring day and night on an exploration voyage down to more than 500m depth in the hunt for nickel sulphide mineralisation.
The Maibele North project spans about 1,500 square kilometres of ground holdings made up of seven leases kissing the venerated Limpopo Mobile Belt and Zimbabwean Craton in eastern Botswana and is located about 400km north-east of the country’s capital city, Gaborone.
Perth-based Si6 says the project area takes in more than 20km of strike and Maibele North nickel sulphide mineralisation relates to ultramafic intrusions within mobile belt rocks. The company surmises Maibele North may be broadly similar in style to other ultramafic intrusion-related mobile belt nickel discoveries such as Nova-Bollinger and Julimar in WA.
The Maibele North diamond hole has so far tunnelled about one-third of the way down to the planned depth to test a deep electromagnetic target that geophysical surveying identified beneath the existing Maibele North resource. Si6 hopes to reach the end point before Christmas.
Drilling has been absent from Maibele North for approximately five years. However, historic drilling by Si6’s previous incarnation, Botswana Metals, led to a mineral resource estimate over Maibele North of 2.38 million tonnes ore going 0.72 per cent nickel and 0.21 per cent copper.
Pre-2015 drilling intersected nickel mineralisation below and along strike of the current resource. The company’s diamond drilling journey to a depth of 500m-plus is designed to intersect mineralisation associated with the strong electromagnetic conductor along an interpreted northern plunge of the Maibele North resource.
According to Si6, the early stages of the deep drilling have been encouraging, with disseminated sulphides including pyrrhotite and pyrite within ultramafic rocks intersected. Pyrrhotite is the dominant sulphide mineral occurring in the nickel-copper-cobalt-PGE ore zone at Maibele North and the main target of the hole.
Si6 Metals Chairman, Patrick Holywell said: “Whilst the drilling (at Maibele North) has been subjected to a slow start due to some rough weather experienced in Botswana, we are thrilled to report our drilling operators have doubled their efforts by expanding to 24-hour, double-shift drilling.”
At the same time, Si6 has almost finished an induced polarisation geophysical survey across the nearby Airstrip and Dibete copper-silver prospects. It is testing for deep, massive to semi-massive sulphide deposits the company says might be feeding the high-grade mineralisation seen close to surface.
Once the IP results have been finalised and interpreted, Si6 says it will look to mobilise an RC rig to site to drill into any intriguing deeper cupriferous anomalies.
Si6 suggests the copper and silver mineralisation at Airstrip and Dibete appears similar in style and geology to the historically significant Messina copper deposits about 230 kilometres to the south-east in South Africa.
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