RE: Ditau Hole i827 Jun 2022 03:05
On 1st June, I posted:
" I have previously speculated here about three possibilities -
* that the I10 'intriguing' core is similar to one I have seen that contained Carlin-type finely disseminated gold in the pyrite.
* that the coincident magnetic and gravity anomalies at I10 are similar to those at the GRS - perhaps another smaller IOCG, this one haematite, rather than magnetite, based.
* a little more speculative is that the apparent layering of mafic & ultramafic rocks may be similar to that seen in the Bushveld Complex, which is the world's largest source of Platinum."
Gold & PGEs don't show up reliably on hand held XRF, mostly due to the likely very low concentrations and fine dissemination. The main value of XRF when looking for precious metals is to identify elements that commonly occur together with gold - the 'pathfinder' metals. As Metalhead has noted, maybe they have seen a Carlin-type pathfinder metal on the XRF, these include not just arsenic, but barium, mercury & antimony. There are different groups of pathfinder metals for different gold deposit styles.
A while back I had some brief correspondence with Ben on the likelihood of this being Carlin-type, clearly the KAV geos are aware of this possibility, equally clear is that he is unable to go into details at this stage. I should point out that most Carlin-type deposits are overprinted on to carbonates, whereas to me the I10 'intriguing core' looks like metamorphosed BIF (banded iron formation), brecciated, then overprinted with silica and pyrite in two different stages.
fyi, the original Carlin trend in Nevada is believed to contain over 500M oz of Au - I don't want to be accused of ramping, so I won't point out that the Carlin in-ground value is over a $Trillion.
From the latest geophysics, I8 does look like a classic carbonatite, the first hole must be at the increased target depth by now, so we will find out soon what the structure is, and if there is likely to be any REE mineralisation.