Aa
This is an old revision of this page, as edited by Aziraphale (talk | contribs) at 20:02, July 13, 2007. It may differ significantly from current revision.
Aa (pronounced "ah-ah" - a Hawaiian term), is lava that has a rough, jagged, spiny, and generally clinkery surface. In thick aa flows, the rubbly surface of loose clinkers and blocks hides a massive, relatively dense interior. (Tilling, Heliker, and Wright, 1987) [1]