Dalradian Resources announces that a sensitivity study estimation performed on two of the major veins in the Curraghinalt gold deposit (T17 and V75 veins) resulted in a 37% increase in grade and a 10% increase in ounces. In the new study, the geology wireframes were re-modelled using assays with a heavier emphasis on logged geology. This approach yields 24% narrower veins accompanied by a 20% decrease in tonnage. (See Tables 1 and 2 below.) Composite length was adjusted from 0.5 to 0.3 metres to reflect the narrower domains, but all other parameters remain unchanged with the aim to isolate the impact of re-wireframing.
Dalradian assessed the impact of the revised modelling methodology on potentially mineable material for the two veins by applying the same parameters as those used in the December 2016 feasibility study (FS). It was found that the revised vein block models resulted in a higher potentially mineable tonnage of 34% and a corresponding increase in mineable ounces of 32% at the expense of a marginal decrease in grade (1.5%). (See Tables 3 and 4 below.)
This change in modelling sequence, where wireframing is carried out on geology and assays, followed by compositing within these wireframes, can in part explain the positive reconciliation between mill and resource (42% more ounces) resulting from the test stopes completed in 2016. (See news releases of September 14 and December 8.)
Patrick F.N. Anderson, President and CEO said, “We are pleased with the results of this exercise, which uses the same drill data to compare the impact of wireframing prior to compositing, in estimating the mineral resources and resulting mineral reserves at Curraghinalt. The new method is the culmination of a great amount of hard work and reflects our better understanding of the deposit. The resulting shapes for the T17 and V75 veins are more heavily influenced by geology as opposed to previous models which were largely grade driven. This has resulted in smoother, higher grade veins that are only slightly narrower than in the previous model. The implications are that we can use longhole mining methods more extensively and bring new ounces into the mine plan which had previously been below the cut-off grade.