Good to have an education thread Grub (btw I can't open your attachments?).
OK no discovery hole yet and some might Pooh hoo the honey pot theory based on hole 7 assays but the theory is very much intact imo.
Disclaimer, altho I'm no geo, here's my crash course why I believe hole 7 assays confirms we're in a massive hem-mag system which majors will be interested in. Warning below is a bit of a thesis, so grab a coffee and I hope this Queen's holiday reading is helpful.
First, check out the Far East ASTER and note the massive Hematite area in pink...
Why is hematite important? Hematite is non-magnetic iron and magnetite is magnetic iron, when it's combined in a 500m interval, as in hole 7, that's a good thing as it suggests a redox zone is being cooked up with chalco, pyrite-pyrrhotite at its core (hence IO - CG) and this occurs in faults creating hydrothermal fluid pathways as 7 Ann suggests...
Again, notice the elements in Hematite rich IOCGs, we have ALL the right stuff elevated and ALL the way thru the entire 1km core (see 1st sentence above)... and note Bi and Zn are high in Hem dominated, not Mag dominated, IOCGs which we have (see Ann assays appendix table).
AND while the graph above shows elevated REEs (Te, Th, U) associated with Hem rich IOCGs, the graph below uses these elements to help 'discriminate' the oxidised hematite redox zones. (Also, note G for the magnetic susceptibility reading ie from Hem to Mag which I'll further explain later) ...
BTW we've got heaps of Thorium in the Far East which is a good sign also (yes, I will stop with REEs, see other thread)....
OK Poet, that's all good and well, but how do we know that we're in a big system (apart from the mountain of world class geophys done on the area) AND why do these Inca Anns always quote monster equivalents (Mt Isa, OD etc)? Surely they're just pulling our leg and why would majors be interested anyway?
Good question. This is where massive sulphides and induced polarisation (IP) come into play.
Remember hole 9 (I think it was) had 800m of massive sulphides? Well, massive sulphides are associated with chargeability (IP)...
Data analyses show that bulk sulphide concentration is the first order factor that explains variation in the IP effect, even for the case of magnetite-related IOCG mineralisation.https://www.tandfonline.com/doi/abs/10.1071/EG15077And why is IP so important? Go back up to the magnetic susceptibility reading G on the above chart. See how it goes from nothing to high readings, well that suggests moving from Hem to Mag... indeed, some geos use IP as the first indicator of an IOCG as it should look like a pin cushion with all the induction arrows facing outwards (from non-mag core to metal halo).
I first noticed these IP pin cushions on a geo video re OD (unfortunately the link no longer works) and I checked it out with Ross to see if I was imagining things when I compared it to the East Tennant IP... Here's some of my email correspondence with Ross that I posted on HC BEFORE Inca's social media embargo:
Enough said. Be encouraged and enjoy the break!
