Models of Deep Faults - Models and Methods of Magnetotellurics - page 331

connect the conductive upper layer (sediments) with deep (crustal) conductive layers
localized within the side resistive blocks (Fig. 9.6a). The crustal layers, the faults
and the sediments form a closed conductive circuit. The transverse currents, which at
low frequencies are induced in the crustal conductive layers, are channeled through
the conductive faults and concentrate within sediments (Fig. 9.6b). This channeling
effect clearly manifests itself over the central segment. Here at low frequencies the
transverse electric field dramatically increases (Fig. 9.6c) and a descending branch
of the transverse apparent-resistivity

⊥

- curves lies far above the locally normal

apparent-resistivity n - curve (Fig. 9.6d).