Hi guys,This sort of talk need not be on the AXT thread. We all...

Hi guys,

This sort of talk need not be on the AXT thread. We all hold stock as we have faith that it will come thru with the goods but i think that a few things need be put forward before any sort of constructive discussion.

1. The "gravity anomaly" that the company drilled the edge of is a computer generated enveloped which is made by taking the data from the gravity points taken at surface and thru processing attempts to differentiate the rock as function of density i.e. the grater the density the higher the gravity peak or high.

The implication of this is that if we take the idealised case of a homogeneous volume of rock which has a density of about 2.7 tons to the meter cubed then filling that volume of rock is with 3 percent copper using the most common copper mineral chalcopyrite which has a density of 4.1 - 4.3 g/cm3 and a copper content of approximately 26 % we find that the volume of rocks weight increases to approximately 3 tons to the meter cubed which is a density which can be achieved by simply having a denser rock in the area.

This is by no means anomalous but does not mean that the density shell is not mineralised.

2. The drill hole which intersected grade went trough a wide section of magnetite alteration.

Before I go into the details of the implications of this I will explain the concept of hydrothermal alteration.

When a metallic deposit is formed a large amount of hydrothermal fluid (carrying dissolved metals as soluble compounds) interacts with the surrounding rock and there is a chemical loss and gain. In a IOCG or Olympic Dam- Prominent Hill type deposit there are 2 alteration types that are relevant to the discrimination of gravity shells.

Hematite and Magnetite alteration increases the density of the rock due to a gain of iron trough the input of these 2 species of iron oxides (IO in IOCG).

In relation to this area of the world the mechanism for the precipitation of the metals out of the fluids is that of a change in oxygen fugacity i.e. the concentration of oxygen in the fluid. This translates into the observation that the grade copper, gold and in one case so far uranium is found where the less oxidised iron species (magnetite which creates a magnetic anomaly) translates into the more oxidised hematite species.

If these 2 anomalies are on top of each other then we get coincident magnetic and gravity anomalies (Olympic Dam) or if the system is turned on its side the anomalies are adjacent (Prominent Hill). Images of the OD and PH anomalies can be found on most IOCG explorer?s presentations as investors tend to warm to these comparisons.

3. The hole intersected grade copper.
Drill a hole down in any direction 300 km of Olympic Dam you will intersect the fingerprint (alteration)of a IOCG system and these carry variable zones of grade. So this can but doesn?t have to mean a lot.

4. The density shell is found at the intersection of 2 large structures.
This means that the shell is found where 2 faults intersect. This I feel to be the factor that impressed me the most but once more there are no guarantees. The intersecting faults create a zone of low pressure where fluids will preferentially flow thru. More fluid= more metal to potentially get deposited.

So IMHO the important factors appear to be there.

IOCG alteration

Adjacent grav and mag anomalies

Presence of copper (although low echelon copper species)

Intersection of 2 crustal scale structures

As to the the silver and copper in the upper sediments. These are not something i particulary care for. These are horizontal orebodies that require room and pillar mining which at these depths is a pain.

I invested in Argo because of these reasons. The low number of shares and the Xtrata partnership made it sweater.

There is no need for claims of bonanza grades of copper or whatever. The facts are there. They look good. But keep in mind geology and mineral systems are enigmatic. And there is no ground to suggest that grades or iuntersects will get better towards the center of the gravity shell (i hope they will).


If I was to write about all of the other rock type?s processes and circumstances that could cause these anomalies this post would be about 50 times longer.

If anyone else is keen to learn a bit more about IOCG?s post your emails and ill send you some reading.

Cheers