In Swaledale, the Stockdale Fault is a major fault that is linked to other major fault systems and marks the northern boundary of the Askrigg Block and southern boundary of the Stainmore Trough. The Stockdale Fault can be seen at Low Bridge and catterby Scar denoted by a limestone escapement along the northern bank of the River Swale upstream of Wain Wath Force. The position of the River Swale has also been partially controlled by the fault as they are natural weakness in the crust, and nature, when eroding the crust, preferentially attacks these broken rocks. Ice and rivers have chosen to use this routeway down the valley as the faulted rocks are least resistant to erosion. The Stockdale fault is a long-lived fault that has been reactivated many times and during latest Carboniferous to earliest Permian times acted as one of the many conduits for hydrothermal fluids depositing the mineral wealth of the dales.