 Astbury agrees that later writers have adopted Fowler's spelling though he still maintains that fenmen call such silted-up old river beds "rodhams".None of the different spelling variations of roddon is found in Robert Forby's "The Vocabulary of East Anglia".Carbon dating of bog oak found in the Fen Edge peat of Adventurers Fen near Wicken, almost from the nearest present-day coast at Kings Lynn, suggests the peat in this area was formed by a large marine incursion in about 2400 BC.