| Abstrakt: |
A magnetic fabric study involving rock samples from above and below the ground was conducted in the mining region of Bleiberg-Kreuth, in Carinthia, Austria. Detailed magnetic fabric and fracture analyses show that the fractures and shear planes are related to the tectonically-produced magnetic fabric. Using this relationship, it is possible to delineate a time dependent tectonic evolution of the study region: the Bleiberg-Kreuth area underwent at least two phases of major compression with a period of relaxation in between. The shear angle, α, and the angle of internal friction, φ, in rocks are important parameters for predicting fracture failure. It is shown here how “in-situ” evaluation of these parameters can be made using the magnetic susceptibility anisotropy; a value of α= 33° and φ= 24° was obtained for the dolomitic rocks of the Bleiberg-Kreuth mines. Determination of the degree of deformation within different rock types and directions of movement along shear planes also are demonstrated. |
