Characterisation of Fractures and Fracture Zones in a Carbonate Aquifer Using Electrical Resistivity Tomography and Pricking Probe Methodes

Position, width and fragmentation level of fracture zones and position, significance and characteristic
distance of fractures were aimed to determine in a carbonate aquifer. These are fundamental
parameters, e.g. in hydrogeological modelling of aquifers, due to their role in subsurface water
movements. The description of small scale fracture systems is however a challenging task. In the test
area (Kádárta, Bakony Mts, Hungary) two methods proved to be applicable to get reasonable
information about the fractures: Electrical Resistivity Tomography (ERT) and Pricking-Probe (PriP).
PriP is a simple mechanical tool which has been successfully applied in archaeological investigations.
ERT results demonstrated its applicability in this small scale fracture study. PriP proved to be a good
verification tool both for fracture zone mapping and detecting fractures, but in certain areas it
produced different results than the ERT. The applicability of this method has therefore to be tested
yet, although its problems most probably origin from human activity which reorganises the nearsurface
debris distribution. In the test site both methods displayed fracture zones including a very
characteristic one and a number of individual fractures and determined their characteristic distance
and significance. Both methods proved to be able to produce hydrogeologically important parameters
even individually, but their simultaneous application is recommended to decrease the possible
discrepancies.