Since the gold grades are so high, and Siren Gold has this flexibility, what do you think the total ounce target could rise to, to if Brian and Paul decided to reduce the grade by 1grams per tonne to 4-5g/t?
Basically, what do you think is the elasticity of the gold grade to total gold resource target?
Could they add 100,000Oz ($A253million), 200,000Oz($A506million), 300,000Oz($A700million) to the current 250,000Oz-500,000Oz target at Alexander River, with this change?Good questions
@Goldhunter122.
My short answer is:
The highly probable upside for Resource expansion for Siren Gold is in mapping existing and new Ore Bodies along strike and at depth [as setout in the prospectus].
I am invested in Siren Gold because I consider that the upside potential for resource expansion is in excess of 10 times the suggested maiden resource i.e 5 million ounce plus.
It should be noted that once the mining operation goes underground, reserve/resource replenishment will become cheaper and can occur simultaneously with mine development and ore extraction.
My long answer is:
4 g/t cut-off grade may well be viable at near surface mining panels which would provide expansion of reported resources established at 6 g/t.
More significant, is the probability that the reported resource will expand significantly by exploration/mineral classification along strike and at depth.
It is known that Blackwater mine produced gold at a depth of 750m and Federation Mining are investing significantly by developing twin underground access roadways to undertake exploration and potentially continue mining activities from the 750m level [see image below]. It is highly probable that the Siren Gold Orebodies will also continue and contain consistent grade at depth.
I recommend using cost per ounce, not gold ore grading, to evaluate a gold mine viability. The reason being is that a "low cost" operation provides protection against the volatility in Gold price. A low cost operation will continue to be profitable at lower Gold prices and can sustain cashflow servicing commitments. There are many examples of marginal mining companies becoming insolvent during commodity price downturns.
Cut-off grades are used to define potentially economic underground mining panels, taking into consideration direct mining and processing costs, commodity prices and other parameters. The economic viability of future mining panels is tested by determining whether the margin, after applying the appropriate cut-off grade, is sufficient to cover the required capital development and mining costs.
Underground mining methods are largely determined by the geometry of the mineralised zones and evaluation may involve review of more than one method. Mine planning is based on 3D block models of in situ mineralisation, with allowances made for minimum mining widths, dilution and ore loss in line with the mining method being considered.
Sensitivities around cut-off grades will be published in any PFS/DFS released by Siren.
Blackwater Mine - Analogue for Siren Gold (Reefton Tenements) Ore Bodies.
(20min delay)