Delta Lithium General Discussion, page-980

The typical density used in the lithium JORC calculations is 2.7. This means that to have a 10Mt JORC resource is approximately 3.7m cubic metres. A 100Mt JORC resource is approximately 37 million cubic metres. An Olympic sized swimming pool has a water area of around 2,500 cubic metres so these volumes are pretty large relative to more relatable everyday stuff.

Considering a perfectly vertical rectangular vertical pegmatite (because that's easiest for the maths), If it was 25m wide, 500m long and 300m deep it would be 3.75m cubic metres and therefore just over 10Mt. The bigger you can get one or two of these length, width and depth dimensions, the easier it is to get to a really big resource. There should also be a lower strip ratio when it comes to modelling mining it which helps on the operational economics. Things like 100m+ intercepts help to get a big resource but you can get a really big resource just through length and depth. Also if 100m+ intercepts are only over a small area, the resource may not be that large anyway. Reality is harder as pegmatites are rounded, they slope and they change shape over their length and depth. They can also included non-mineralised areas - particularly on the edges.

Several Delta slides/reports have talked about two pegmatites each having consistent mineralisation over 1.6km (but they don't note average depths or widths). Noting this calculation is on two not six main peg's drilled 2 x 1,600 length x 15 ave width x 300 average depth =14.4m cubic metres. 14.4*2.7 density = 38.9Mt. So if the average true width was 15m and on average 300m of depth a calculation around 40Mt is easy to arrive at. It could also be that I've over-stated the two main peg's but the other 4 make up this difference. Some of this may not be economic to mine (areas that are too thin/deep) so there's a loss when converting from resource to reserve. Bell Potter recently put out a revised 40Mt resource estimate and 30Mt potential reserve. I presume they have used mapping software for all reported intercepts so its a better guess than this back-of-envelope calculation. Note - I'd chosen some inputs that got a number similar to Bell Potter's. This is an estimate on known drilling. The huge wildcard is on yet to be reported drilling and on pegmatites that are yet to be drilled.