Ann: Significant Resource Upgrade at Twin Hills Project, page-9

A lot of gold producers and resource holders are using 0.4 g/t Au cut off.

At current A$2500/oz gold price 0.4 g/t Au is ~ $32/t rock, at 90% recovery - $29/t recovered value, still attractive with process costs of $12 to $15/t.

Lower grade ounces might be stockpiled to front load the grade through a plant.

At the end of the day it will come down to strip ratio, costs and recoveries.

Note the extra ounces were all above the >1050RL, so probably inside an existing pit. So already being mined.

The whole Drummond Strategy is to get a larger resource base to sustain lower unit costs – larger mining rates – lower costs, larger process plant throughput – lower costs.

Note that GBM’s Koala resource used 0.4 g/t Cut-off in 2019.

See below from Gold Road:

https://goldroad.com.au/ore-reserve-and-mineral-resources-statements/

AllOpen Pit Mineral Resources are evaluated using variable cut-off grades allowingfor processing costs, recovery and haulage to the Gruyere Mill, and reportedat: Gruyere and YAM14 – 0.4 g/t Au. Attila, Orleans, Argos, Montagne and Alaric– 0.5 g/t Au. Renegade, Gilmour, Smokebush and Warbler – 0.5 g/t Au

AllOpen Pit Mineral Resources are constrained within an A$2,000 per ounce (GruyereJV) or an A$2,200 per ounce (Gold Road 100%) optimised pit shell derived frommining.

Also see below from EVN

Evolution – Mungari Resource 0.5 g/t Au – ASIC 1800 to 1900