Pahoehoe Lava

Pahoehoe lava flows are characterized by ropy, billowy, bulbous textures, whether on the surface or on the floor of a cave. It is a Hawaiian word that literally means “smooth.” It is the type of flow most likely to produce lava tubes. Lava tubes are usually floored with pahoehoe, but that pahoehoe often grades into a more frothy, cauliflower a’a  floor.

The first three photos are classic examples of ropy pahoehoe on a lava tube floor. The fourth photo shows an unusual variant found in some tubes that this author calls dendritic pahoehoe. It’s not clear what the mechanism for its formation is.

Note that red is by no means a typical color for pahohoe in caves…the darker swirls of the third photo are more typical, though in this photo there are some white minerals crystallized on top of it. All these images are from caves in Hawaii.