3D ZTEM Inversion Results
International Montoro Resources Inc.
Serpent River Property
Elliot Lake, Ontario, Canada
245 Industrial Parkway North
Aurora, Ont., CANADA, L4G 4C4
• ZTEM_MT3Dinv program was used to perform the inversion with topography and bird
altitude effects considered.
• One block was used during inversion. The cell size in the core area is 100m x 100m x 20m,
with vertical cell size geometrically increasing at depth below minimum topo. XIP, XQD, YIP,
and YQD components at 3 frequencies of 90, 180, and 360 Hz were used for the inversion.
• The initial model was a 5000 ohm-m homogeneous half-space. The inversion resistivity
range was [1-100000] ohm-m.
• A relative error of 50% was applied to the data. A tipper noise floor of 1% (absolute value)
was assumed. The inversion converged after the 9 iterations.
• Slides 3 shows flight-path over PLM image. The thick-paths indicate where the tipper data
were affected by powerline noise and were not used in the 3D inversion.
• Slides 4 & 5 show IP 180 Hz DT and analytic signal images with location of inversion lines.
• Slide 6 shows a map with Mesh and SRTM data used for 3D ZTEM inversion. The block dot
indicates the location of the Base Station.
• Slides 7 to 10 show 3D views of the inversion results.
• Slides 11 to 32 show resistivity sections for each line.
• Slides 33 to 49 show resistivity depth slices in the first 1500m on an interval of 100 m.
• Slides 50 to 62 show tipper maps of field data and model responses for different frequency
• Slide 63 shows convergence curve for 3D inversion results.
• Slide 64 shows the conclusions
• Slide 65 shows references for 3D ZTEM inversion
3D ZTEM inversion was successfully performed on the
Tipper Transfer functions acquired over the Serpent River
Property, Elliot Lake, Ontario, Canada. The 3D Inversion
results are presented as 3D voxel model, Resistivity depth
slices from 0 to 1500 m at 100m depth interval and
Resistivity cross section along all flight lines.
1. Holtham, E. and Douglas W. Oldenburg, 2010, Three-dimensional
inversion of ZTEM data, Geophys. J. Int. (2010) 182, 168–182
2. Oldenburg D. W. and Y. Li, Inversion for Applied geophysics: A
3. Holtham E. and Douglas W. Oldenburg, 2012, Large-scale inversion
of ZTEM data, GEOPHYSICS, VOL. 77, P. WB37–WB45