Figure F16. Characteristic structures of rubbly pahoehoe flow. A. Photograph of a rubbly pahoehoe lava with smooth flow base and rubbly flow top consisting of slabs of pahoehoe crust and a'a-like clinker (partly covered by moss [light gray]). The person is shown for scale. B. Sketch showing the main structural components of a rubbly pahoehoe lava flow in a vertical section.