Abstract The sequence and nature of Quaternary events have been determined principally from evidence in coastal sections, cave sequences and extensive spreads of unconsolidated sediments in the Somerset and Avon lowlands. Correlation is hampered by their isolated nature and scarcity of samples for dating. It is generally agreed that Southwest England was not overrun by Pleistocene ice sheets. Fragmentary evidence for the encroachment of an ice sheet along the present north coast, from the Isles of Scilly to north Devon, is, however, widely recorded. It takes the form of giant erratics on shore platforms (e.g. Saunton), possible glacigenic gravels (Isles of Scilly, Trebetherick and Lundy Island) and glacial deposits (Fremington) (Stephens 1973). This has led to the notion that the most extensive of the Pleistocene ice sheets reached its southernmost limit at or near the north Devon and Cornish coasts.