INCO AEM DIGITIZING Breathing New Life Into Old Data Brian Bengert
INCO AEM DIGITIZING Breathing New Life Into Old Data Brian Bengert
INCO AEM DIGITIZING Breathing New Life Into Old Data Brian Bengert
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<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Breathing</strong> <strong>New</strong> <strong>Life</strong> <strong>Into</strong> <strong>Old</strong> <strong>Data</strong><br />
<strong>Brian</strong> <strong>Bengert</strong>
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Introduction<br />
• Over 1 000 000 line miles flown from 1950 to 1984<br />
• A simple, and unique system designed to collect frequency<br />
domain EM data with a large transmitter receiver<br />
separation<br />
• The system packages included up to 18 channels of Alt,<br />
EM, Mag, and Spec data<br />
• 80% of anomalies have yet to be ground evaluated<br />
• Approximately 100 000 line miles digitized to date
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Airborne <strong>Data</strong>base Coverage<br />
Yellowknife<br />
Nain<br />
Goose Bay<br />
Edmonton<br />
Thompson<br />
St John’s<br />
Charlottetown<br />
Regina Winnipeg<br />
Toronto<br />
Quebec<br />
Halifax<br />
Airborne Survey Coverage<br />
0 500<br />
km<br />
Sudbury<br />
Fredericton
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Value of <strong>Data</strong> - Historically<br />
• Deposits discovered with the Inco <strong>AEM</strong> system:<br />
u<br />
u<br />
u<br />
Thompson Manitoba<br />
150 million tons<br />
3% Ni<br />
Heath Steele<br />
20.7 million tons<br />
4.79% Zn, 1.75% Pb, 1% Cu, 65 g/ton Ag<br />
Casa Berardi<br />
10.5 million tons<br />
8.2 g/ton Au
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Thompson Manitoba<br />
8<br />
A.E.M. Signal<br />
4<br />
0<br />
Parts Per<br />
Hundred<br />
Overburden<br />
0<br />
400<br />
ft<br />
Ore Zone<br />
Iron Formation<br />
Peridotite<br />
Granite Gniess<br />
Sediments
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Value of <strong>Data</strong> Today<br />
• Why are these data valuable today?<br />
u<br />
u<br />
u<br />
u<br />
Scope and pace of programs meant that not all EM<br />
anomalies were followed up.<br />
Standard anomaly classification system de-emphasized<br />
some important kinds of responses.<br />
Contoured Magnetic data have never been seen.<br />
On-time data with greater depth of search than modern<br />
helicopter systems.
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Inco <strong>AEM</strong> vs. Modern Airborne Systems<br />
EM System<br />
Tx-Rx<br />
Separation<br />
Receiver<br />
Altitude<br />
(metres)<br />
(metres)<br />
Helicopter<br />
EM<br />
Frequency<br />
Domain<br />
10<br />
30<br />
Modern Fixed<br />
Wing EM<br />
Time<br />
Domain<br />
130<br />
80<br />
Inco <strong>AEM</strong><br />
Frequency<br />
130<br />
53<br />
Domain
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Original Hardcopy Products
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Original Flight Record<br />
Altimeter<br />
Coaxial & Coplanar<br />
Mag<br />
EM Phases<br />
EM<br />
Signal Ch.
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Digitizing The Flight Roll - Magnetics<br />
Coarse Mag<br />
Fine Mag is coloured by degree of over-scale
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Digitizing The Flight Roll<br />
Coplanar<br />
and<br />
Coaxial<br />
Phases<br />
Signal<br />
Channel
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Original Compilation Map<br />
Magnetic<br />
Trend<br />
0 1<br />
km<br />
<strong>AEM</strong> Conductors
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Digitizing the Compilation Map<br />
0 1<br />
km
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Triangulation<br />
Inco <strong>AEM</strong> Worksheet<br />
Modern NTS Sheet
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Total Field Magnetics<br />
<strong>INCO</strong> Survey <strong>Data</strong> vs. Government Survey <strong>Data</strong><br />
OGS Erlis Mag<br />
Inco’s Mag<br />
0 5<br />
km
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>AEM</strong> System Configuration<br />
Transmitter<br />
(Aircraft)<br />
Co-Planar<br />
Field<br />
Co-Axial<br />
Field<br />
Receiver<br />
(Towed Bird)<br />
Co-Axial Coil<br />
Co-Planar Coil<br />
Co-Axial Coil<br />
Co-Planar Coil
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Induced Current Patterns<br />
Schematic<br />
Coaxial<br />
Vertical Coplanar<br />
Tx<br />
Tx<br />
Conductive body
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
EM Channels<br />
Coaxial Coils<br />
Coplanar Coils<br />
Signal Channel<br />
0 0.5<br />
km
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Difference in Flight Directions<br />
Flight Direction<br />
Flight Direction
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Original Interpretation Scheme<br />
Width of response on flight record<br />
+1- +2- +3-<br />
Example of plotted response<br />
Amplitude of response on flight record<br />
Highest<br />
A<br />
B<br />
C<br />
D<br />
1<br />
1<br />
1,2,3<br />
1,2,3<br />
1,2,3<br />
2 or 3<br />
3,4 or 5<br />
4 or 5<br />
3 or 4<br />
3,4 or 5<br />
1<br />
A1+<br />
E<br />
3 or 4<br />
4 or 5<br />
Lowest
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Re-interpretation of the Signal Channel<br />
Original Interpretation<br />
Plate Model Fitting
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Interpretation Schemes<br />
2<br />
C 2<br />
1<br />
A1-<br />
1<br />
1<br />
A2-<br />
1<br />
2<br />
A2+<br />
C2<br />
3<br />
1<br />
E2-<br />
1<br />
1<br />
1<br />
Original Interpretation<br />
<strong>New</strong> Interpretation
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Scale Modeling<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0<br />
-420 -320 -220 -120 -0.2 -20 80 180 280<br />
-0.4<br />
-0.6<br />
-0.8<br />
-1<br />
COP<br />
CAX<br />
SIG<br />
Tx<br />
Rx<br />
Conductor
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Interpretation Software<br />
Priority 1<br />
Priority 2<br />
Priority 3<br />
Priority 4
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Depth of Penetration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Data</strong> Integration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Data</strong> Integration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Data</strong> Integration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Data</strong> Integration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
<strong>Data</strong> Integration
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Conclusions<br />
• Over 1 million line miles of data exist including nearly every<br />
greenstone belt in North America.<br />
• The contoured magnetic data have never been seen.<br />
• Original EM interpretation favoured short wavelength<br />
features.<br />
• Approximately 20% of identified responses were followed<br />
up.<br />
• <strong>New</strong> interpretation tools can permit us to better prioritize<br />
targets.<br />
• Modern data integration software can help put this<br />
exploration resource into better geological perspective.
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Acknowledgements<br />
• <strong>Brian</strong> Booth, Steve Balch and Alan King who initiated this<br />
process<br />
• Ray Whitton and the rest of IGI for all of their outstanding<br />
work<br />
• Ray Parisotto, Ben Polzer, Barry Satchelle, Dave Walsh,<br />
Carl Laamanen, and Wim Vanderklift, for their technical<br />
and/or historical input.<br />
• Aurora Platinum is gratefully acknowledged for allowing us<br />
to present data.
<strong>INCO</strong> <strong>AEM</strong> <strong>DIGITIZING</strong><br />
Acknowledgements<br />
• Finally I would like to thank the Inco <strong>AEM</strong> crews who<br />
designed and flew these systems, for leaving a well<br />
documented data set with such enduring quality and value.