A Guide to the Unconformity follows writer and campaigner Horatio Morpurgo as he reads one small corner of the English Channel against the grain of empire, extraction and environmental crisis. Taking Lyme Bay and the Jurassic Coast as his laboratory, he weaves together deep geological time, fisheries and quarrying, archival discoveries and the recent struggle for marine protected areas. The book offers a model for connecting coastal geology with politics and economics, and shows how small alliances of divers, fishers, scientists and citizens can win real gains.