Hi @Learner72
I can answer some of your question. Orebodies are classified in 3 categories, Measured, Indicated and Inferred. These categories have firm criteria , and are required for what is termed a JORC resource ( the Australasian Code for the reporting of exploration results)
Measured resources are the portion of the orebody that has the highest confidence, ie that has had both detailed and shallow , closely spaced drilling. Indicated is a little less certain, but still pretty confident. Inferred is considerably less confident and maybe based on just a few drill holes, widely spaced, or even on the geological structures being similar .
This is mostly just a matter of how many drilling dollars you have available, as drilling is expensive.
TIE have a total resource of 3.45 million ounces spread over the 3 categories. As they have finite resources, they have proved up only enough measured resources for the first 18 mths of production or so ( the 350 K oz you refer to). Don’t worry, there is much more gold than that.
As they generate more cash, they can do additional drilling that will ‘convert” Indicated tonnes to Measured, and Inferred tonnes to Indicated. This is why they do ‘infill’ drilling, to check that the gold is continuous between widely spaced holes.
As to your other question about short ? metres of gold, yes, it is common for the gold to be present in relatively narrow bands ( usually a different type of rock) which is sandwiched between other layers of waste rock. Think quartz veins running through a mine.
When the ore is mined, much of the material will be designated waste , and stockpiled untreated, whilst the ore ( rock with economic quantities of gold in it) will be mined and fed into the processing plant for treatment. This is called the strip ratio . How many tonnes of waste you have to remove to get 1 tonne of ore.
Apologies if this wasn’t what you wanted to know, and for being so long-winded about it.
(20min delay)