Midtier mining group Gold One’s Tulo shear-hosted gold mineralisation exploration target, in the north-western part of Mozambique, 20 km south of Tanzania, will start an exploration diamond drilling programme in September.
Gold One investor relations VP Grant Stuart tells Mining Weekly that exploration drilling will start once assay results from completed surface and trench sampling have been received, reviewed and combined with geological mapping to define priority targets for the exploration drilling programme. The existing assay results are expected to be published during this month’s quarter.
A high-resolution helicopter-borne geophysical survey of Tulo, which was completed during 2012 by international airborne geophysical survey company Fugro Airborne Surveys, identified a 20.5 km magnetic lineament.
Two types of gold mineralisation are recognised on the property – primary gold mineralisation associated with steeply dipping shear-hosted quartz veins and alluvial gold. “While the alluvial gold has, historically, been mined on a small scale by artisanal miners, the economic mineral potential of the primary mineralisation has been largely unexplored on the property,” says Stuart.
Mapping, trenching and sampling of a prominent 2 km quartz vein outcrop, which forms the southern portion of the 20.5 km magnetic lineament, was carried out during September and December last year, and 47 trenches had been excavated by then.
Forty of these trenches exposed quartz veining, which was subsequently sampled and analysed by analytical services company Performance Labor- atories, a subsidiary of multidisciplinary mining company Time Mining, in South Africa.
“Initial sample results are being modelled and are undergoing final quality assurance and quality control reviews, including duplicate and round-robin analyses,” he adds.
Where deemed appropriate, Gold One is also considering ground magnetic surveys to refine the definition of structural discontinuities associated with potentially mineralised quartz veins.
Independent exploration drilling company Discovery Drilling Contractors will undertake the exploration drilling programme. The company assessed the exploration terrain and logistical parameters to determine the type of equipment required for the 2013 drilling programme in April last year.
Meanwhile, logistics company Malawi Lakeside Services has been contracted to transport drilling equipment across Lake Malawi to Tulo.
The exploration programme is largely results driven and, as drilling during the rainy season is unlikely, the weather will have some impact.
Phases 1 and 2 of the drilling programmes are scheduled for completion by mid-2015.
Gold One will focus drilling on three major targets, says Stuart.
“The exploration drilling programme will initially be focused in the TL1 target area, where most of the trenching and mapping information has already been obtained. “The programme will consider about 10 000 m of drilling, targeting a strike length of 3 km, which should be sufficient to undertake a scoping study to demonstrate that there is sufficient economic benefit to continue with the exploration programme,” he explains.
“Pending a successful Phase 1 outcome, a second drilling phase is expected to take place, considering a further 11 000 m. The aim of this drilling will be to increase both the size and confidence in the mineral resource,” Stuart adds.
This will also ensure that a prefeasibility economic study can be undertaken.
A third drilling phase, aimed at targeting the definition of a total resource target comprising more than one-million ounces, on which a feasibility study will be completed, is also envisaged.
Once sufficient mineralisation and ore reserve have been identified, Gold One aims to start with the establishment of mining infrastructure.
Owing to the lack of infrastructure in this area of Mozambique, transport for project personnel and equipment has remained a primary challenge for Gold One. “As a result, the company had to construct a 20 km drill rig access road on the concession area.
“The access road was severely damaged by tropical storms soon after its completion, which resulted in significant costs as a result of the construction of a new road and project delays.
Further, the project’s location which is close to the Tanzania border attracted illegal Tanzanian miners and continues to be a risk.
Despite this, Gold One has received strong support from regional and national levels of government and from local businesses, as well as noting an overall mining-friendly jurisdiction in which to work.
The company has achieved several milestones at the project to date, including the construction of the Savannah Bay exploration camp, the establishment of a fully functioning Metangula transit camp and the completion of the 21 km access road to the Tulo site.
Further, Gold One is pleased to have gained excellent results from the airborne geophysical survey conducted last year and from the 42 sampling trenches through its motivated exploration and supporting teams.
The company has also established friendly communication with government officials and good relations with local communities, which will aid the company in progressing the Tulo exploration project through each successive stage of the project’ life cycle.