Cliff-top dune

Cliff-top dunes, also known as perched dunes, are dunes that occur on the tops of cliffs. They are uncommon in most parts of the world, because they only develop under unusual geomorphological conditions. Processes by which they may be formed include:

• a dune advances up a pre-existing slope, which is then eroded to form a cliff;
• a dune forms during a period of high sea level, then sea level drops, exposing a cliff face.

They are most often seen as coastal landforms, but can also occur along lakes and rivers, and in deserts. Places where they are relatively common include the west coat of Jutland, Denmark. They can also be found in certain places along the shores of the Great Lakes in Michigan, including the Grand Sable Dunes in Pictured Rocks National Lakeshore and in the Sleeping Bear Dunes National Lakeshore, most dramatically on South Manitou Island.

References

• Saye, Samantha E., Kenneth Pye and Lars B. Clemmensen (2006). "Development of a cliff-top dune indicated by particle size and geochemical characteristics: Rubjerg Knude, Denmark". Sedimentology 53: 1–21. Bibcode:2006Sedim..53....1S. doi:10.1111/j.1365-3091.2005.00749.x. 

v t e Coastal geography Landforms Anchialine pool Archipelago Atoll Avulsion Ayre Barrier island Bay Baymouth bar Bight Brackish marsh Cape Channel Cliff Cliff-top dune Cliffed coast Coast Coastal plain Coastal waterfall Continental margin Continental shelf Coral reef Cove Dune Estuary Firth Fjard Fjord Flat coast Freshwater marsh Fundus Gat Geo Graded shoreline Gulf Headland Inlet Intertidal wetland Island Islet Isthmus Lagoon Machair Marine terrace Mega delta Mouth bar Mudflat Natural arch Peninsula Raised shoreline Reef Regressive delta Ria River delta Rocky shore Salt marsh Shoal Shore Sound Stack Steep coast Strait Strand plain Submarine canyon Tidal island Tidal marsh Tide pool Tied island Tombolo Windwatt more ... Beaches Beach cusps Beach evolution Beach morphodynamics Beach ridge Beachrock Modern recession of beaches Pocket beach Raised beach Shingle beach Storm beach Wash margin Processes Blowhole Coastal biogeomorphology Coastal erosion Concordant coastline Current Cuspate foreland Discordant coastline Emergent coastline Feeder bluff Fetch Headlands and bays Large-scale coastal behaviour Longshore drift Marine regression Marine transgression Rip current Sea cave Sea foam Shoal Spit Submergent coastline Surf break Surf zone Surge channel Swash Volcanic arc Wave-cut platform Wave shoaling Wind wave Wrack zone Management Accretion Coastal management Integrated coastal zone management Submersion Related Bulkhead line Coastline length Intertidal zone Littoral zone Grain size boulder cobble clay granule pebble sand shingle silt Physical oceanography Region of freshwater influence more ...