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04/11/17
08:48
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Originally posted by eastwest101
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The way I read the announcement was that J1 J2 and J3 were all modelled to strike roughly north south and dip steeply towards the west. These are modelled dip and strike from the ground EM that they used to design holes 5 and 6 (that's why holes 5 and 6 are drilled towards the east). Now that they drill holes through the conductors they can do their down-hole EM loop thing and this will be able to tell them more about the conductors "conductivity" and position, so the modelled dip and strike may "change" once they have done the down-hole EM survey, and is also useful to help the geophysics experts predict if there is something near the holes that may even be more conductive that the stuff they have in the drill holes. Any decent off-hole conductors may/should be followed up later by further drilling.
From the presentation the geology and geophysics all seem to say roughly north south trending stratigraphy with steep dips, although as you get closer in there is often more structural complexity possible such as faulting and maybe some folding, in my (non-gephysics qualification) experience the J1 conductor is OK, J2 is obviously really good (chalcopyrite conducts better than most other sulphides) and J3 was the least confident predicted conductor so it isn't surprising that maybe a thin lamellar Qtz-Pyrrhotite zone (or even a thin graphite rich band or graphitic fault) may explain J3.
Whatever the case - at the moment J3 look uneconomic in the one place where they do have a drill hole in it, but that's not to say that it may be more copper rich (Chalcopyrite) and less Iron rich (Pyrrhotite and Pyrite) along strike or up or even down dip. Its quite common to see uneconomic pyritic or pyrrhotitic zones adjacent to or at the margin of or along strike from higher grade copper/gold rich pods/lenses/orebodies in NW Qld Eastern Fold Belt. Each orebody is unique but I have seen a few orebodies that are zoned with different sulphide minerals associated with different gangue minerals in different parts of the mineralized system.
The MEP guys are now in a much better position than they were before holes 5 and 6 were drilled because they now know that the ground geophysics can find sulphide mineralization and some of this mineralization is possibly economic, now its just a case of using down hole EM and geology and then the drill to find more economic mineralization. Usually orebodies are discovered by "near-miss" holes that have enough sulphides, are conductive enough and enough anomalous elements to be followed up by further drilling. Usually after the near miss (but sometimes years later!) there is a spectacular "discovery hole" where the best widths are grades ever seen are obvious as the nose on your face, and then comes the boring follow up drilling on 50m and then 25m section spacing to totally drill out and understand all the intricacies and complexity of the orebody.
Sorry for the long boring post but that's my take on it - without looking at the rocks myself. The MEP guys would obviously know a bit more than this.
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@eastwest101
Thanks for that post (and others)
From some of the comments that you have made in your posts on MEP, I gather you have either work at or studied the Eloise deposit.
I was reading a few published articles on the Eloise deposit and came across this one below:
Unfortunately is states the following:
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Searching the article under the following or similar would probably bring it up.
EloiseQueensland , Australia
I found it very informative as to the geological setting of the region and immediate area around the Eloise Mine and was interested to know if you were either familiar with it, or had an opinion on its contents.
MI
PS Sorry for those that would have liked to have read it straight up but Copyright is copyright.