geological organ

   A cylindrical or funnelshaped cavity in relatively soluble bedrock which typically has a vertical orientation and is partly or wholly filled with material similar to the overlying sediment cover. They are produced by solution of bedrock and concomitant subsidence of its sedimentary cover. Most have a diameter of 25 cm to 7 m and a depth of 2 to 30 m, but some may be much larger. A depth/diameter ratio of 5 to 20 may be considered representative. In actuality, geological organs are a type of subsidence doline that develops under a cover of younger rock or sediment [17].

   Synonyms: (French.) Orgue géologigue, poche de dissolution, puits naturel; (Belgian.) abannet, cavité de dissolution; (German.) geologische Orgel, Orgel, unterirdische Doline, Verwitterungssacke, naturlicher Schacht, Erdorgel, Erdpfeife, Riesentoph, Bodenkarren, ( British.) sand pipe, sand- gall, gravel- pipe, pipe, pocket deposit, gull; (Italian.) organo geologico; (Roumanian.) orgile geologice; (Czech.) geologické varhany; (Polish.) organy geologiczne; (Russian.) organ truba, kamin; (Serbo-Croatian.) geološke orgulje; (Slavic) geološke orglje, zapolvje jaški; (Dutch.) geologische orgelpijp, aardpijp.