bar tombolo A deposition landform such as a spit or bar which forms a narrow piece of land between an island or offshore rock and a mainland shore, or between two islands or offshore rocks. They usually form because the island causes wave refraction, depositing sand and shingle moved by longshore drift in each direction around the island where the waves meet. Eustatic sea level rise may also contribute to accretion as material is pushed up with rising sea levels. ENVO ENVO:00000420 EcoLexicon:tombolo SWEETRealm:Tombolo Wikipedia:Tombolo bar island