Lava#.CA.BBA.CA.BB.C4.81

Aa- lava or Brockenlava (sometimes: Zackenlava ) is of the different lava types zähflüssigste the form. The name comes from the Hawaiian language, and was introduced by Clarence Dutton in the geological jargon. It means burning, fiery, rocky.

During solidification and partial crystallization of the melt flow breaks the crust, leaving a surface that is interspersed with sharp-edged, irregularly shaped, jagged lumps and clods.

Compared to pahoehoe lava AA lava flows more slowly and is cooler; often it is in the lower part of low-viscosity lava flows because of outgassing and cooling increases the toughness. At the end of the stream, it forms a steep front.