The fault zone has been traced seaward in either direction from its landfalls west of Bideford in north Devon and Torbay on the county's southeast coast.
Two sedimentary basins have developed along the line of the fault; at Petrockstowe in mid Devon and Bovey Tracey on the eastern margin of Dartmoor.
During the Eocene and Oligocene epochs, around 600m thickness of sediment accumulated in the former and 1200m in the Bovey Basin.
Both are interpreted as pull-apart basins which opened as a result of dextral slip on the fault.
[1][2] The Stanley Bank Basin east of Lundy within the Bristol Channel and perhaps also the tiny Flimston Basin in southwest Pembrokeshire, lie on the northwesterly extension of the fault zone.