I thought I'd have a quick back of the envelope calculation of...

I thought I'd have a quick back of the envelope calculation of what sort of volumes/tonnes you could expect from the upcoming Maiden Resource at Antler. Was going to run a few figures of the "interpreted shoot" at different average ore thicknesses e.g 3m, 5m, 10m, 15m, 20m etc. NWC have helped out by giving a block scale (50 x 100m) and the SG (3.9) in their announcements. 100m x 50m x 20m x 3.9(SG) = 390,000 tonnes

I thought I'd start by seeing how thick the historic resource must have been to give the 4.7M tonne of ore @ 3.4 Cu eqv. It looks as though about 3 of the 100x50m blocks would fit in the indicated historic resource area, so have gone with that figure. Have used the following equation.

((Length(100m) x width(50m) x thickness(unknown)) x 3 (for three resource blocks) x Specific gravity (3.9) = 4.7M tonnes
((100 x 50 x T) x 3) x 3.9 = 4,700,000
Thickness = 80m

A thickness of 80m for the historic resource area seems too large by a factor of 10. My question is can anyone see where I went wrong in the calculations or how to get 4.7M tonne from the historic resource area?

Figure I used with overlay of blocks in red below.