A systematic study has been carried out concerning ground water in faults and fractures in a granite rock and the results are compared with those of uniaxial testing of granite specimens in rock mechanic laboratories. Dikes of diabase intersect the granite and indicate the plane of deformation syntectonic to the dikes. A collection of the tectonic data from the granite is statistically treated and the tectonic picture of the area fits very well into the deformation plane, indicated by the intrusion (Jotnian).
The faults and fractures of the granite are, according to their position in relation to the plane of deformation, hypothetically interpreted as tension and shear faults. The faults in shear position are supposed to be tight and have very little ground water. The tension faults, on the other hand, are supposed to be open and to be capable of a high yield of ground water. This hypothesis is tested by core-drillings, percussion drillings and test pumping.