Keywords: Åva ring.jpg en Åva ring structure in Brändö Åland It is a ring shaped structure caused by a 1 billion years old magma chamber that has failed to erupt as a vulcano nl Åva ring in Brändö Åland own Erik Wannee 2012-04-30 Cc-zero Maps of Åland Geological maps of Finland Brändö Magma chambers Structural geology maps |