phoehoe
Phoehoe lava is thinner than a'a, and flows more readily. Its surface looks more wrinkly and smooth. Phoehoe lava flows in a series of lobes that form strange twisted shapes and natural rock sculptures Figure below . Phoehoe lava can form lava tubes. The outer layer of the lava flow cools and solidifies. The inner part of the flow remains fluid. The fluid lava flows through and leaves behind a tube Figure below .