There are two main types of basaltic lava flows. They are:
Pahoehoe (pronounced ‘paw-hoey-hoey”): Pahoehoe lava is characterized by a smooth, billowy, or ropy surface.Pahoehoe flows tend to be relatively thin, from a few inches to a few feet thick.
A’a (pronounced “ah-ah”):A’a is characterized by a rough, jagged, spinose, and generally clinkery surface. Aa lava flows tend to be relatively thick compared to pahoehoe flows.