Related Clues:

• Rock on a roll?
• Volcano feature
• Molten rocks
• Volcanic discharge
• Soap containing volcanic pumice
• Rock that runs
• Source of basalt
• Ejected magma
• Magma, after surfacing
• Soap brand containing ground pumice
• Etna outflow
• Etna ejection
• 56-Across's output
• Red river?
• Magma on the surface