Once again, you missed the mark by a country mile. EastWest is crapping on about degrees of randomness in the sampling. Seems the ASX can’t grasp the concept either.
The accuracy or repeatability of the assay grades don’t matter when you’re up around the 10-12 oz/t range and it doesn’t matter what part of this beast you sample on the 10s – 100s of metres scale. This is broad, intrusion-scale mineralisation disseminated throughout the rock, probably formed in the magma melt.
Don’t believe that it’s intrusion scale mineralisation? Then how come we’re getting very similar grades of 12oz/t in a separate gabbro at Ema, kilometres from Tres Estados?
The reason grade and tonnage and all the other parameters pertaining to an orebody matter is because they are needed to decide if mining should proceed or not. We already know the answer to that question but we need a mining permit so we need to plug a few holes into the Tres and Ema gabbros and obtain a mining permit.
The grade matters most when you’re close to the cut-off grade, i.e. the grade boundary between ore and waste rock. The grades at Tres-Ema are so far off the scale it doesn’t matter. They are going to struggle to find waste rock in the mineralised zones of the gabbro. Of course there will be some zonation, but it’s broad scale zonation.
Here’s a good example of mining selectivity or grade control when you’ve got broad scale zonation. Note the scale. Those mining blocks are up to 1.5km long. They’re taking everything in those mining blocks and putting it through the mill. Good article by the way: https://www.geologyforinvestors.com/great-deposits-grasberg-part-3-mining-engineering/
