Orinoco Gold (ASX: OGX) has achieved more bonanza gold grades including a whopping 300 grams per tonne gold after assaying ore from the Cuca zone at Cascavel in Brazil.
This second batch of 38 panel samples averaged 48.3g/t gold with better results including 222g/t gold, 212g/t gold and 184.5g/t gold.
The first batch comprised 35 samples and assayed, on average, at 31.7g/t gold with peak gold grades of 212g/t.
Both batches were taken from historic workings at the Cuca deposit and were analysed at an external certified laboratory, with a combined the median gold grade of 40.9g/t.
According to Orinoco, gold mineralisation in Cuca is similar to the Cascavel and Mestre deposits within the projects and visible gold had been identified in exposed veins and samples.
“The Cuca panel samples results further increase our confidence that the Cuca-Cascavel-Mestre system represents a potentially very high-grade mineralised system, which is open in all directions and characterised by several high-grade mineralised veins,” Orinoco chief geologist Dr Marcelo J de Carvalho said.
He added the project’s geology suggested the gold mineralisation is extensive and supports the company’s expansion plans.
A drilling program has been scheduled for next month to test the mineralisation along strike and at depth.
Orinoco is looking at Cuca to become a near-term producer as part of its overall Cascavel operation.
In late February, Orinoco noted if this second assay batch was positive, it would look at beginning trial mining at the end of March, with a decision on whether or not to proceed made soon after.
Cascavel hammer mill operation
After a rocky start where the Cascavel operation failed to produce economic gold, Orinoco reviewed its project and applied a “back to basics” approach.
The review found the initial gravity circuit was unsuited to processing Cascavel ore and a hammer mill was trialled.
Since the hammer mill pilot program began late last year, Orinoco has reported numerous high-grade gold recoveries with each processing campaign, including today’s announcement.
Because of the finer-style gold mineralisation, the hammer mill has been able to crush the ore into smaller particles and achieved much larger gold recoveries.
Hammer mill four was due to be commissioned this month and has a 50 tonne per hour capacity to complement existing operations including the 25tph hammer mill three, which was installed in January.
Orinoco’s share price soared 9% in early morning trade to A$0.12.