<P> The coastline of the island consists of a combination of long beaches , dunes , red sandstone cliffs , salt water marshes and numerous bays and harbours . The beaches , dunes and sandstone cliffs consist of sedimentary rock and other material with a high iron concentration which oxidizes upon exposure to the air . The geological properties of a white silica sand found at Basin Head are unique in the province ; the sand grains cause a scrubbing noise as they rub against each other when walked on . Large dune fields on the north shore can be found on barrier islands at the entrances to various bays and harbours . The magnificent sand dunes at Greenwich are of particular significance . The shifting , parabolic dune system is home to a variety of birds and rare plants and is also a site of significant archeological interest . </P>
why does prince edward island have red sand
sedimentary rock and other material with a high iron concentration which oxidizes upon exposure to the air