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Gold/Mining/Energy : Gallery Resources (Alberta GYR) -- Ignore unavailable to you. Want to Upgrade?


To: Wesley Barbowski who wrote (1258)6/2/1998 8:40:00 PM
From: 1king  Respond to of 1829
 
Wesley,

This is my own professional opinion all others are welcome to disagree but the TC comment:

"BTW--Gallery is to be commended for acquiring MT before"

is not a ringing endorsement. I won't puts words in Terry's mouth but we have discussed the issue on several occasions.

Large loop soundings completed by LGL have detected conductors to 700m and have been used in basin analysis to km deep scales. The data is cheaper, more robust, easier to acquire, easier to interpret and yields less ambiguous results.

My point is using MT to detect an anomaly at 1000m deep puts you no further ahead. It could be sourced by a formational contact. Most are. or the source could be laterally displaced form where it appears. MT surveys ALWAYS RETURN ANOMALIES. This detracts from the method in general. The economics of a 1000m conductor are not very good, this point you can research and also come to your own conclusions.

EM soundings of this nature frequently generate shadow zones. That being a zone of "conductivity" extending to depth from a more shallow causative body. I believe this to be the case here. This may be explained by the presence of the shallow (17xxft) conductor.

I may be able to prove this more quantitatively with the raw data from all surveys (now I just use little jpegs) but then Gallery would have to waste there money on my services <gggggg>.

Anyways, "dollar for dollar, metre pe metre of drilling on them, this and virtually all MT surveys conducted in Labrador in the past couple of years are not worth a pinch of cow shit". Including those at Voisey. My opinion only but its a good one.

MT does have other applications, I am not against any method (except teck in 1997 = virtually no EM but that's another story) but they have limited application here at this stage in the game

1King

Please let me know if this helped



To: Wesley Barbowski who wrote (1258)6/2/1998 10:10:00 PM
From: 1king  Read Replies (1) | Respond to of 1829
 
Hello Again,

Just checked the PR. Its a PR with PR type hype. Just a positive promo type discussion. There are as many people at INCO who disagree on the "test" at Tril. MT is not a definition-type survey, period. Anyway to each their own, I advise my clients on the basis of efficient systematic exploration. MT is way down my list as a last ditch effort for deep pockets. I take back, it being useless, as all data is useful in one form or another. Usually formational information is generated.

1King



To: Wesley Barbowski who wrote (1258)6/3/1998 11:01:00 AM
From: Kent C.  Respond to of 1829
 
Hi Wesley,

After some discussion, Gallery decided to use Phoenix Geophysics Magnetotellurics (MT) Survey in 1997 to follow up on work done in 1996. Before Gallery used the MT, Gallery had already completed 30 km of Total Field Magnetics (TFM), Very-Low Frequency (VLF) and Horizontal Loop (HLEM). (This year we are doing 80 km of gridding) The TFM confirms and enhances the strength of the magnetic anomlay (discovered by Airborne Magnetic and Electromagnetic Surveys in June 1996).
The VLF and HLEM surveys do not yield corresponding electrical responses normally produced by concentrations of sulphide minerals. Analytical Modeling of magnetic data indicates a buried source, of a relatively simple geometry approximately 200 metres in diameter, at a depth possibly below the detection limits of VLF and HLEM electrical surveys.
It was because of this that Gallery decided to conduct an MT survey of a 30 km grid. Information published by Phoenix Geophysics in March 1997 states that the MT survey technique is capable of detecting conductive mineralization as deep as 2,000m or 6,500 ft.
MT Survey results based on reading from 48 sites allowed Phoenix to conclude that: 1) The Okak Bay survey imaged an anomalous layer of enhanced electrical conductivity at a depth of approximately 1 km (3,300 feet) centered on survey grid coordinate 300 east and 500 north 2) the zone of enhanced conductivity appears to be approximately 400 x 400 m in size which also hosts a much weaker conductive layer at a shallower depth of approximately 400 m 3) the zone of anomalous conductivity appears to be spatially coincident with an airborne magnetic anomaly previously identified by Gallery Resources Ltd.

The mineralized zone from Hole OK-M1 roughly coincides with the shallow, weak electrical conductor outlined during the MT Survey.

In November 1997, a borehole UTEM-3 electrical survey of Hole OK-M1 carried out by LaMontagne Geophysics, specialists in borehole surveys, identified a good quality off-hole anomaly. Their interpretation shows this anomaly may represent a good quality conductor 100 to 200 m from the hole with a size between 100 and 200 m. The size potential is moderate for a lens shaped conductor and could be greater for other shapes. The conductor is located at approximately the same depth of the mineralization intersected in drill core. This suggest that the in-hole disseminated mineralization could represent a halo around a body of more concentrated mineralization (semi-massive eg.) capable of producing the good quality off-hole anomaly.

In February 1998, Petrographic (microscope) examination of drill core reveals that the sulphide mineralization contains nickel rich (pentlandite and pyrrhotite) and copper rich (chalcopyrite) minerals which are the important sulphide minerals at Voisey's Bay. The core contains abundant biotite as does the host troctolite at Voisey's Bay.