Tridimensional geometry of the limestone-quaternary cover interface

Electrical tomographies are the ideal tool for differentiating resistant units to more conductive ones. The resistivity contrast between resistant limestones and conductive clayey lacustrine sediments is particularly suitable for this method. A regular grid of electrodes covering 8,000m2 allowed to make a real 3D ERT acquisition.

3D inversion procedures adapted to this type of dataset allows the possible restitution of underground resistivities as a three-dimensional block. Advanced visualization tools bring advanced analysis and interpretation of these results.

Advanced visualization tools increase the accuracy of 3D interpretation

The final 3D volume allows us to clearly highlight the limestone top interface (between 0 and 8 meters below ground level).

This 3D acquisition involved the setup of 8 parallel electrodes line
Location Switzerland
Instrument Syscal Pro
Geometry 96 electrodes, 10m grid
Positioning DGPS
Sequence Pole-dipole
Length 8,000 m2
Personnel 5 people
Duration 0.5 days