As interesting and illuminative as Q's response is, New2Quizzes is, how do you Brits say? Spot on... My well worn, dog-eared College level, Rocky Mountain Geology text book defines "dentelated beach" as a shoreline, ancient or modern, consisting of well worn, irregular indentations defined by crevassed shore lines. Much of the coastal erosion occurs along zones of weakness created by faults and fractures. Instead of a homogeneous retreat of the cliff/sea border line, one has erosion by dissection. As one of these zones of weakness is attacked by the waves, a surge channel begins to form. Over time, these channels deepen and widen. Eventually two or more channels will coalesce and an embayment will form. Finally the shore platform in front of a particular reach of cliff will be removed and an accelerated period of cliff erosion will commence. Additionally, rivers, streams and other sources of inland water-ways assist by erroding deepening channels from within the interior of the mainland... Authored by Dr. E.C. Knight, with whom I had the distinct pleasure of taking notes in well organized classes, majoring in Geology...