Detailed analysis of the recent exploration results from War Eagle's Mac Tantalum property...
I agree with Candykid, these geological press releases are all "geo", not much "logical" and are about as easy to read as hieroglyphics. That being the case, let's see if our tenuous command of the Queen's English might serve us well enough to pick this PR apart, to parse it perfectly and perhaps to depart with an appreciation of the property's potential.
We must look the first paragraph square in the face because the rest of the PR is meant to prove its premise. To quote the PR:
"The 2001 results have demonstrated the property's potential to host significant tantalum/tin mineralization over a strike length of at least 12 km and a width of 2.5 km. The program has outlined two specific areas in the northern and southern parts of the complex where more detailed work will be focused to establish tantalum/tin drill targets early in the 2002 exploration season."
These unequivocal statements are very simple: There's enough tantalum and tin in the samples to indicate that the site may have significant quantities of both minerals within a 12 km by 2.5 km area and that the north and south parts will be explored early in 2002 to determine the best drill targets. It's good news and the goals of this year's exploration plan were fully met. War Eagle's deal with Strategic Minerals Ltd is that War Eagle will spend $2,000,000 in exploration over the next 3 years and the announcement states that it's full speed ahead with the program. We're right on track.
After these rather important statements, the PR lapses into geo-speak and the outright mystical. We read of dikes, dike swarms and pegmatite while words such as bifurcate, Voodoo and Berlin Wall are used with seemingly wanton recklessness. Let's wrest control of the conversation from the geoscientists and place it back into our world.
Pegmatite is coarse granite occuring in the form of dikes or veins. A dike is a body of igneous rock (granite) formed when molten granite flows into a fissure. A dike swarm is a closely grouped bunch of dikes, some of which bifurcate (branch) into one another. The pegmatite is light to medium grey in colour, somewhat salt and pepper in appearance with quartz sparkling in it. The dikes are very visible in photographs, their light grey colour standing out from the surrounding mid to dark brown sedimentary rock. So picture a very rocky, hilly landscape with light grey pegmatite veins running in it, each half a metre to 10 metres in width, some parallel, some intersecting and you are beginning to picture Mac.
There are 7 dike swarms so far described at Mac. They each contain as many as 25 dikes which are each, in turn, 0.5 metre to 10 metres in width. The sum of the widths of the dikes within a swarm is greater than 25 metres with some being 50 metres in combined width. The Mac dike swarms stretch in a Northwest direction within a 12 km long and 2.5 km wide area. Each dike swarm ranges in width from 40 metres to 500 metres and is up to 5 km long.
Now, let's tackle verticle relief, down-dip thickening and the "walls". From one of the photographs taken from the top of a rocky, barren Mac hilltop, it can be seen that a large dike runs under one's feet, disappears over a cliff just metres away and emerges into view running up the hillside in the distance, on the other side of the valley. The view is very much like standing on the Great Wall of China and looking across the valley to a far hillside with the Great Wall snaking its way up and over the top. The dike in the photo (dike swarm actually) looks very much like this and has been named, appropriately enough, the Great Wall of China. With that precedent set, subsequent dike swarm discoveries have all been named after walls of one sort or another, Climbing Wall, Wall of Voodoo, Prison Wall, Hadrians Wall, Berlin Wall and Wall Mart.
So if a dike runs up a hill and down the other side into the valley below, it implies that the dike may run deep through the hill as well, all the way down inside to the hill's bottom and perhaps deeper. Verticle relief is really the height of the hill. The report mentions one hill has 300 metres of verticle relief and has a dike appearing to run completely through it. Only drilling can confirm that these hills have dikes running through their hearts, top to bottom, but the implication is there. The closer to a hill bottom that one views the dike, the wider the dike gets. This is down dip thickening. The report describes 7 dikes as having down dip thickening of 600% per 100 metres of verticle relief. Every 100 meteres down, the dikes are 7 times as thick as they were 100 metres above. This implies that what we see on the surface is only a fraction of what's below and is how these formations normally occur. Ah, no-brainer here, this is good. Pass me a drill.
Back to pegmatites. Pegmatites can have a bewildering array of compositions. The report speaks of 5 different general types at Mac. The middle area of the property consists mostly of the lithium bearing type, the SQF or spodumene type. However, the north and south portions of the property contain larger quantities of the QM type which contains far greater quantities of tantalum and tin. The 5 pegmatites are visually different from one another. However, within a type, there is no way to visually predict the amount of tantalum in the sample. "Channel samples" are collected by cutting a channel across the width of a dyke with a portable diamond circular saw and then removing the sample. "Specimens" are broken off of dikes where it is impractical to use the saw. "Chips" are loose pieces picked up by the geologist. Bear in mind that the Sons of Gwalia Greenbushes mine produces ore at an average of 226 grams/ton of Ta2O5.
It looks like a greater portion of the exploration took place in the central area than in the north or south. Of 209 channel samples, 161 channel samples were taken from the SQF pegmatite which is higher in lithium and lower in tantalum and occurs mostly in the central area. All "specimens" (34) average 441 g/t. The 7 QM "channel samples" show an average 234 g/t of Ta2O5 while the 16 QM "specimens" average 659 g/t. The press release indicates that an area of great interest was discovered in the south late in the season. It appears that some quick specimens and channel samples were obtained from the south but due to time constraints, adequate samples were not obtained from the most encouraging areas, both in the north and south. But what samples we have!
Since the central area is stated to be 4km by 1 km in area, this leaves 8km of total length in the north and south to be explored more fully. This year's activity has clearly indicated where further exploration must be concentrated. A final report on this year's exploration will come in February. It will tell us the lithium concentrations and will include the exploration and proposed drilling plans for the summer of 2002. The indications are that we have high concentrations of tantalum and that the volumes may indeed be on a scale of magnitude similar to that of Sons of Gwalia.
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