| Abstract: | Evidence from 1,450 boreholes and coastal seismic profiles adds further precision to the form of the sub-drift channels of South Lancashire and North Cheshire. These channels resemble sub-aerial valleys, but commonly have ungraded profiles locally reaching at least 289 ft (87 m) below O.D. In some places they are still below present sea level, 40 miles (64 km) inland. It is suggested that previous views of origin can be reconciled by considering them to be river valley Systems, partly rejuvenated by low Pleistocene sea levels, and locally modified by sub-glacial meltwater. |
