地球内部过程 Geologic Tectonics Faults Only very small faults have a simple, clean-cut plane of movement. The majority are zones of shearing, usually a few metres across, but major faults may be more than 1 km wide. Within the fault zone there may be a number of planes of movement displacing the strata by distributive slicing, or the rock may be completely fragmented to form a fault breccia where competent rocks are affected, or clay gouge where incompetent rocks have been smeared out by shearing ( Gouge often acts as a seal to make the fault zone locally impervious to groundwater circulation. At the walls of the fault the strata may show terminal drag in the direction of relative movement 环境迪顶学 minoucntalocelogu ,率地球内部过程 Geologic Tectonics • Faults Only very small faults have a simple, clean-cut plane of movement. The majority are zones of shearing, usually a few metres across, but major faults may be more than 1 km wide. Within the fault zone there may be a number of planes of movement displacing the strata by distributive slicing, or the rock may be completely fragmented to form a fault breccia where competent rocks are affected, or clay gouge where incompetent rocks have been smeared out by shearing. (Gouge often acts as a seal to make the fault zone locally impervious to groundwater circulation.) At the walls of the fault the strata may show terminal drag in the direction of relative movement