Hi
@m0ngy, I dont want to get in some massive flame war over this. As a reply however I've taken some excerpts from GN31, which explains the requirements of Chapter 5 of the listing rules. It is my unfortunate experience that many Competent Persons (CP's) are not even aware that these exist, especially on the Geology side.
There's a lot more that can be read about this but that's the bones of it.
And a couple from JORC 2012;
You will find that almost all Scoping Studies that are published tend to contain a fair bit of Inferred material. From memory - I couldnt find a direct reference - the ASX gatekeepers usually dont like it to be more than about 40%, but it is allowed to be up to 100%. If you want direct examples I can point you at some but I'd have to read through a few I've archived away over the years, from memory if you look up Triton 2017 or Mt Morgans 2015 you can get examples. There are no doubt hundreds of others out there.
I'll concede that the Listing rules and GN31 imply that Modifying Factors are expected to have been "considered" for an MRE, and in theory Table 1 should include details of any that have been considered in the past, but it is only the RPEEE requirements that specify it in JORC itself and RPEEE is rarely complied with or enforced in the majority of MRE's that you see being published. You almost never see any mention of minimum mining unit, gold price assumptions, geotechnical assumptions or similar things mentioned in an MRE.
RPEEE enforcement is something that is coming and is starting to be implemented by some of the major mining houses but it is not yet common, even though it has been in JORC since at least the 1999 edition.
Again, from JORC2012;
Which is identical wording to JORC 1999 and 2004. Of course there was also always the requirement that Ore Reserves be derived following a full PFS or FS but this was rarely if ever done until JORC 2012 made it clear that it would be enforced. The amount of work required to do an OR since then has tripled or more. RPEEE enforcement will both increase the work required and seriously reduce the size of many MRE's that are out there.
In practice, for most MRE's, and it appears to also be the case if you look closely at the latest announcement, everything over a cut-off grade that is not already mined is reported - without consideration of things like excluding tiny little resources or stranded resources that are not worth chasing or resources that do not fit inside a Whittle shell generated using reasonable assumptions (for surface mining) or able to be mined by MSO shapes that are constrained by reasonable mining assumptions (for Underground). You will find mention in the Table 1 of the expected mining methods but nothing about MMU's. Like I say, it is coming but it has not historically been enforced and a lot of CP's are not even aware of it. Sad but true.
Regarding your other points; a 60% res/res conversion rate is the rule of thumb figure I was first given more than 25 years ago. I've had many many others mention the same figure over that time. It only applies until you have a reserve of course but it is an industry accepted number.
I stand by my 30% figure - there is still a long long long way to go. And it's a gold mine, of course it's patchy. The Deeps just dont look patchy because they dont have enough holes in them yet. Look at the upper parts of the mine and that is what you can expect once you get more holes in it. It is not by any definition "high confidence". Just read the Table 1's and you'll see all sorts of qualifying statements.
Actually, I'm a little surprised this one made it past the ASX gatekeepers. Or even to the gatekeepers. I mean just look at page 2, reporting Inferred tonnes to 4 significant figures (combined totals to 5 figures) and grades to 3 significant figures. I mean that's CP 101. I'm amazed that two CP's signed off on that "in the form and context in which it appears", let alone whoever wrote the ann or whoever authorised it to be sent out. Not exactly confidence inspiring.
(20min delay)