Specifications

University of Pretoria etd – Combrinck, M (2006)
200 m, 250 m, 300 m
h
Layer
= 20 m
can be mistaken for two
layer earth.
Conductive layer in
half space (varying
host rock cond.)
σ
HS
= 0.0002 S/m,
0.005 S/m, 0.0067
S/m, 0.01 S/m, 0.02
S/m, 0.04 S/m and
0.1 S/m.
σ
Layer
= 0.2 S/m
d
Layer
= 150 m
h
Layer
= 20 m
Host rock conductivities
< 0.01S/m results in the
depths decreasing with
time of cumulative
conductance plots,
although the extent of
this reversal is less than
for the same contrast in
a more conductive host
rock.
Depth of investigation
determined by host rock
conductivity or shallower-
than-first-channel-depth
conductive layer.
Higher host rock
conductivities cause more
severe “non-late-time”
distortions in early
channels.
Conductive
horizontal plate in
half space (varying
hor. dimensions)
σ
HS
= 0.02 S/m
σ
Plate
= 0.2 S/m
l
Plate
= 100 m, 200 m,
300 m, 400 m
d
Plate
= 150 m
h
Plate
= 20 m
Smoothly increasing
with depth.
100m too small to
resolve with current
parameters.
Depths are slightly
underestimated proportional
to side length of plates;
underestimation of
conductivities just below
plates.
Low contrast.
Conductive
horizontal plate in
half space (varying
hor. dimensions)
σ
HS
= 0.02 S/m
σ
Plate
= 2 S/m
l
Plate
= 100 m, 200 m,
300 m, 400 m
d
Plate
= 150 m
h
Plate
= 20 m
300m and larger side
lengths produce
decreasing depths with
increasing times.
100m too small to
resolve.
100m and 200m side lengths
give negative conductivities
below plates.
High contrast. Second
instance when negative
conductivities can be
calculated.
Conductive prism
in half space
(varying
dimensions)
σ
HS
= 0.02 S/m
Smoothly increasing
with depth.
100m too small to
resolve.
Depth to top and
conductivity values resolved
better than thin plates.
Low contrast.
300m and larger
dimensions resemble
infinite layer apart from
underestimation of
98