Hi,Here are some additional thoughts about what might be...

Hi,

Here are some additional thoughts about what might be contained in the upcoming assays.

In my humble opinion, if there’s going to be high grade copper in the form of chalcocite and/or bornite, it’s more likely to be a lot higher in the Vulcan breccia complex. Possibly as much as 300m-400m higher. VUD018 has probably passed through part of the barren core, sub-vertically, and then out of it at fairly considerable depth (as the hole progressively headed more in a sub horizontal direction rather than sub vertical), and almost straight into the lower chalcopyrite zone. The first section on the way out of the barren core might contain some decent gold and silver grades, along with some copper and possibly uranium.

Re the mafic lithologies, dykes, etc.: IOCG deposits are highly complex and variable i.e. just about anything is possible.

In VUD018 TAS said there were only minor intervals of altered quartzo-felspathic gneiss in the massive hematite zones. Nevertheless, the presence of felsic and mafic extrusives or intrusives (ie. of magmatic origin) is generally very good, and this is all part of the many formation processes required to create these complex and highly variable deposits.

In VUD019, IMVHO, most of the mineralisation will likely be in the 321m interval they mentioned from 1302m to 1623m down hole. The remaining 244m of the hole sounds like it passed through (sub-horizontally), and then largely out of the lower/outer margins of the Vulcan breccia complex. The presence of mafic dykes is also quite OK, and these are also fairly widespread at Olympic Dam (including in the barren core). The presence of quartz is also quite OK, as this is also fairly widespread in certain sections at OD.

Re the colloform massive hematite breccia in the 1 drill core pic that was released, this sort of material is mentioned as being present (possibly in the early formation/alteration stages) at Oak Dam East, where it has probably been altered and mostly replaced in the massive hematite zones.

Although I am optimistic about the results of the upcoming assays, TAS just haven’t provided us with anywhere near enough information to interpret things in any sort of meaningful way. Publishing one lone picture from the vast amount of drill core that were available is bordering on the ridiculous when it comes to getting any sort of true overall picture of the rocks and minerals and alterations that FMG have encountered in these two holes.

For further information about the geology, mineralisation etc. of Olympic Dam, which will be similar to what FMG have just encountered at Vulcan North, please take a look at the following article:

http://www.portergeo.com.au/tours/iocg05/iocg05deposits.asp

In this article, there are two references to the "barren core", which IMVHO are very important, as they are highly likely to also relate to what FMG has just encountered in their first two holes at Vulcan North:

The better mineralisation and strongest alteration outside of the barren core corresponds to the best-developed hematite-granite breccias. The concentric, moderate to steeply inward dipping breccia zones of the ODBC are cut by a convoluted, but overall roughly horizontal, ~50 m thick layer characterised by chalcocite and bornite, ~100 to 200 m below the unconformity with the overlying Neoproterozoic cover sequence. Both the upper and lower margins of this zone are mappable. Above the upper margin, sulphides are rare and little copper mineralisation is found in the same hematitic breccias. The lower margin marks a rapid transition to chalcopyrite, which decreases in copper grade downwards, corresponding to an increase in the pyrite:chalcopyrite ratio. While this zone is largely horizontal, as it approaches the central barren core it steepens markedly, but is still evident at depths of >1 km below the Neoproterozoic unconformity (Reeve et al., 1990; Reynolds, 2000; Ehrig, 2010). The geometry of this mineral zonation, strongly suggest interaction between upwelling and downward percolating fluids. For all fluids related to hematite alteration, fluid inclusion homogenisation temperatures are mostly between 150 and 300°C and salinities range from ~1 to ~23% NaCl equiv. (Knutson et al., 1992; Oreskes and Einaudi, 1992; Bastrakov et al., 2007).

In addition, in order to highlight the difficulties that were encountered in trying to find the mineralisation "hot spots" at Olympic Dam, the following statement from this article tells me an awful lot:

The higher grade underground resource occurs as up to 150 separate bodies distributed within an annular zone up to 4 km in diameter surrounding the central barren hematite-quartz breccia. These bodies correspond to the overlap of the flat-lying chalcocite-bornite layer and the steeper, inwardly dipping ring of hematite-granite breccias.

Wishing you all a profitable week.