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To: Terry J. Crebs who wrote (357)3/19/1998 6:47:00 PM
From: Walt  Respond to of 463
 
Thanks Terry, its always good to get two or three view points on these questions.
Im always dubious of VLF anomalies for the reasons you stated. Shears and faults are always clouding things up. A good max-min survey gives one a much more accurate picture of what is really going on.
As you pointed out magnetics and other surveys can be a little tricky because one strong anomaly will affect other weak anomalies around it and one isnt necessisarily looking for the strongest or weakest anomaly.
I feel geophysical surveys should always be read in conjunction with the known geology. Unfortunately often the geologists and geophysists work seperately. This cqan lead to some costly mistakes.
regards Walt



To: Terry J. Crebs who wrote (357)3/19/1998 7:33:00 PM
From: 1king  Read Replies (1) | Respond to of 463
 
Terry,

The ovoid was not "missed" on the first 5 of 6 holes.

FACT:
After the discovery, a ground mag/vlf/HLEM survey was conducted from the main gossan area, east to line 13+00E, SHORT of the ovoid. A systematic drill program moved from west to east testing a dyke-like conductor. The drill results improved as the program moved east and the geophysical surveys were extended to the east (then and only then over the ovoid). VB94-02 intersected 33.20 meters of massive sulfides with nearly 7% combined Ni/Cu! A geophysical consultant from St. John's, Newfoundland was hired to interpreted the new data during the Christmas break 1994-95 (an example of the early workers trying to be prudent). He spotted holes 6 and 7 based on a dyke-interpretation of the HLEM data because of the earlier drilling. The broad anomaly could have been interpreted both ways, I guess (just being nice), but it looked more like a depth limited wide-body conductor. Hole 6 was spotted on the basis of this report, to intersect the "dykes" at depth, but came up empty (undercut the ovoid). So the contractor's report was trashed and a scissor hole (07) was spotted. The rest is history!

Although this period was just before my tenure I compiled all the geophysical data reports and interpretations during my initial work. I must say Terry, that statement and its implication show a lack of class and I would expect better from someone with your experience! You owe the early people on that project an apology!

Respectfully
M.S. King, P. Geo.
Chief Geophysicist
Voisey Bay Project
1995-96