Dr. Jim Mungall – AGM

I’m just going to say a few words about the geological model that we’re using to guide our exploration program in the lowlands, and really, it’s a fairly simple conceptual model. It’s the assimilation of iron formation by komatiite. So, komatiite is a magma type which doesn’t form on the earth anymore, but they were relatively common in the Archean , 3 billion years ago. They’re extremely hot magmas which came up out of the mantle, much hotter than magmas that you see in the earth today. Hot enough so that you can take just about any type of crustal rock and chuck it in there, and it’ll melt and dissolve, and it’s the assimilation of other crustal rocks which causes the formation of the ore deposits that we’re interested in.

Iron formations were a fairly common type of sedimentary rock in the Archean, they’re sediments which are unusually rich in iron, either as magnetite or sulphide minerals, or even as silicate minerals. And depending on the flavour of the iron formation that goes into the komatiite, you get different types of deposits. The form of deposit like Eagle 1, which is a magmatic massive sulphide deposit, it’s necessary for the komatiitic magma to dissolve iron formation which is rich in iron sulphide minerals. And when that occurs, an immiscible sulphide melt forms. That means that that sulphide liquid is like a separate magma which doesn’t actually dissolve in the silicate in the ultramafic magma but they’re like oil and water. And the droplets of sulphide melt scavenge the nickel, copper, platinum, palladium, gold and so on from the magma and concentrate it, the same way as a fire assay concentrates those metals in the laboratory. And because the sulphide melt is dense, and it’s immiscible, it forms a separate pool on the lowest point of whatever intrusion you happen to be dealing with.

But we looked for accumulations of dense sulphide minerals at the bottoms of (ultra?)mafic intrusions which represent what’s left of these komatiitic magmas.

In the case of chromite deposits, we’re still looking at the same magma type and in fact we can form both kinds of deposits in the same intrusion but in this case it seems that the key process which precipitates chromite, is the assimilation of silica and magnetite, which are also components of these iron formations. So when you add silica and magnetite to the komatiite, it becomes over-saturated in this mineral chromite, Mg or Fe Cr2O4 . Chromite is a dense mineral and like the sulphides, it wants to go to the bottom, but unlike sulphide, it’s a solid, it’s not a liquid so it can’t trickle down and collect at the very bottom. Instead, it falls to the bottom of wherever the melt reacts (sic?) with the other crystals are forming, to form layers. So we’re looking for layers of chromite on the bottom of flat-lying intrusions, and we’re looking for pools of sulphide liquid at the very lowest points of the intrusions that we’re dealing with.

And the way that we can use this kind of model with the geophysical data which is available to us is to consider how these different types of ore deposits respond to geophysical methods. So the sulphides are very magnetic, the mineral pyrrhotite and magnetite are both magnetic, so we can use magnetometers to detect them but what’s more useful for the sulphides is they’re very good conductors. They’re like electric wire buried in the ground, so if you fly over them with a transmitter receiver arrangement, like an AeroTem system or VTEM system, you can actually detect the presence of these conductive bodies deeply buried beneath overburden. So that’s the third way of exploring for the sulphide deposits.

The ultramafic rocks that host the deposits are also very magnetic, they contain a lot of magnetite and so we can detect large intrusions which may be the host of ore bodies of magmatic sulphides just by looking for big blobs of highly magnetic rock. So we can use magnetometer surveys for that as well.

And the chromite deposits don’t have those same kinds of geophysical responses, they’re not magnetic, and they’re not conductive but what they are is dense. We’re looking at rocks which are 50, 60, 70 percent chromite and chromite is a dense mineral so we can use gravity surveys to detect large concentrations of chromite. And we’ve had some success with that, and that’s our preferred method going forward to find more chromite.

So, in 2007, when the first hole was drilled at Eagle 1, this is what was known about the geology in the area of interest here.

This is a geological map, I’ve perhaps oversimplified a bit but the little tiny black dots are outcrops, and they’re all essentially granite. So, as of 2007, this whole area was thought to be underlain by granites and it wasn’t very interesting. But the discovery of the VMS deposits off to the east here in 2003 aroused a lot of attention, and made people realize that maybe there was more under this swamp than people realized.

Using the existing magnetometer survey results that had been compiled by people looking for diamonds, people like Renforth who came in and staked these little isolated mag highs, other people came in chasing VMS deposits. Noront picked up a big piece of ground in here ( gesturing). This is just a portion of the Ring of Fire, this is the portion I’m concentrating on because that’s where the discoveries have been. But other people like Freewest and Probe are in here as well. So we picked up a lot of the very highly magnetic rocks which are either iron formations, which are good hosts, or the ultramafic intrusions, which are, of course, the immediate hosts to the deposits.

Airborne surveys were flown to try to find conductors, and AeroTem and VTEM , these are both electro-magnetic methods I’ve briefly described before, and what we get back from these surveys are pics of places which are thought to be underlain by conductive bedrock.

The AeroTem conductors are yellow on this map, and the VTEM ones are red but basically they’re saying the same thing: if you drill there you should encounter something which is conductive, which may be a magmatic sulphide deposit.

So drilling is what we’ve done, Noront’s been drilling here at Eagle 1 and at Eagle 2 and Blackbird, up here at AT12, and Freewest and others have been drilling in the middle.

And we’ve compiled all this information together, the mag fabric, the occurrence of conductive bedrock, inferred from airborne surveys, and by looking at the drill results of the drill program we have an idea what the actual rocks are, so now we can draw on that.

So here’s the geological map as it stands now, it’s still going to be revised as more information comes along but we have a fairly good idea now what we’re looking at. The brown here is the oldest rock in the area, this rocks are probably about 2.8 billion years old. And when they were perhaps a hundred million years old, they were eroded off flat and they were covered by a thin sheet of iron formation , which is now here ( pointing to where?) and then that was then overlain by more iron formation and volcanic rocks, basalts and so on, including the VMS deposits over here.

After some time, and we’re not exactly sure how long, that stack of sediments and volcanic rocks was inflated by granitic intrusions, the pink rocks that you see on maps of the Canadian Shield, and it just sort of inflated the whole stack, and subsequently to that, the purple intrusion came in. This is the ultramafic intrusion that’s the focus of all the excitement. So this intrusion along here was a flat lying body which we call a sill, and that’s where we’re finding chromite, and projecting down off of it, downward at that time is up on this map, are these spiky things which were dykes. These were cracks in the earth, filled with ultramafic magma, into which sulphide liquid could drain.

So what we’ve got now at the tip of each one of these cracks is a sulphide deposit. AT12 is here ( pointing) , that one’s still being explored. Eagle 1 is here in one of these little cracks. It looks little here but it’s several hundred meters long and goes down forever.( repeats here, perhaps at the request of a listener) Eagle 1, little crack here, it’s actually a few hundred meters long and goes down, we don’t know how far, but it’s open to depth, AT12 is here, this one is still being explored. All of these dykes are actually projecting downward off of this sill, and subsequent to the formation of the intrusion and the end of the all the action the whole system was folded so that this structure was turned on it’s side. Down is that way, up is that way ( gesturing).

The chromite deposits formed along the flat part of the intrusion where they could just settle, and form, if you want to think of them as being like sandbars on the bottom of this intrusion as the magma was flowing through, piling up the chromite into sheets.

Blackbird 1 over here ( pointing) is sitting directly underneath the Eagle 2 sulphide deposit. We went over here to Blackbird 2 and found more chromite, and we’ve been stepping back through and so far what you’ve seen in the latest visuals from the press releases is that we continue to find chromite in between.

Freewest has chromite here ( pointing), Freewest, Spider, KWG I should say. Freewest has chromite here and here ( pointing) . Everywhere that this intrusion has been drilled, there’s massive chromite. So, we can infer if we want to be blue-skies, optimistic that the entire belt may contain massive chromite , all the way from here ( pointing) all the way around this completely untested mag anomaly and up to the northeast.

So Noront has tens of kilometers of untested potential for chromite as well as some other ultramafic dykes which haven’t been completely tested, and all the down-depth, down-plunge potential underneath Eagle 1 and AT12 and Blackbird 2.

So, just to sum up, when Eagle 1 was drilled in August 2007, this was basically what we knew about the area.

In one year, we’ve learned a tremendous amount, and among the things that we’ve learned the last 15 months is that we have two very interesting nickel deposits, at least two chromite deposits, tremendous untapped potential here, and we still have something like 300,000 acres left to explore.