AbstractThe application of sedimentological and other techniques in a detailed small‐scale study of Quaternary meltwater deposits around Pentraeth in Anglesey, North Wales has shown that interpretations based solely on surficial form are incorrect. Previous views held that the sediments were deposited sub‐glacially as eskers by meltwater flowing south‐west from decaying ice in Red Wharf Bay.The present work shows that in general the deposits form a coarsening upwards sequence with distinctive divisions corresponding to the lacustrine, deltaic and fluviatile phases of basin filling. The glacigenic sediments were transported by rivers flowing predominantly south‐eastward and deposited in a shallow lake o