Information Technology Reference
In-Depth Information
Fig. 11.46
Pseudo-sections
of the transverse apparent
restivity
⊥
and impedance
phase
⊥
in a model with the
horst in the upper layer;
(
a
) the model cross-section,
(
b
) pseudo-section of
⊥
,
(
c
) pseudo-section of
⊥
a conductive basement,
2
- layer forms a
rectangular ledge imitating a horst. The pseudo-sections of the transverse apparent
resistivities,
3
=
1Ohm
·
m. The surface of the
⊥
, are oriented across the horst.
Both of these cross-sections demonstrate intensive anomalies reflecting the horst.
But anomaly of
⊥
, and transverse impedance phases,
⊥
has a false deep root in the lower part of the pseudo-section.
This root is caused by the static shift of the low-frequency branches of transverse
⊥
-curves (the
S
- effect). At the same time, the anomaly of
⊥
is closed within
the upper part of the pseudo-section related to the
1
- layer and does not violate
the horizontal layering of the underlying medium. So, comparing the amplitude and
phase pseudo-sections, we can get a good image of the horst and outline the area
with strong static distortions of the
⊥
- curves.
A prominent example of the pseudo-sections of the effective apparent resistivity
and impedance phase,
eff
and
eff
,
is given in (Ranganayaki, 1984). Figure 11.47
