Surface Geophysics For Mapping Faults, Shear Zones And Karstification

The main ground water occurrences in crystalline rock terrains are<br>generally limited to fracture zones and alluvial pockets. This is particularly<br>true-for glaciated areas where weathering layers have been removed. However,<br>the importance of fracture and shear zones in controlling ground water yield and<br>quality is not confined to crystalline rock. In, for example, the Permian Basin<br>in West Texas, brine may move along fractures and influence water quality in<br>tertiary aquifers. In the limestone aquifers of the southeast, karstification<br>generally is controlled'by shear zones which often are important aquifers.