Related Clues:

• Red river?
• Magma on the surface
• Source of pumice
• 58-Down output
• It forms igneous rock
• 9-Down output
• Volcanic threat
• Steamy flow
• Content of some cones
• Flowing rock
• Hawaiian figurine material
• Pinatubo output
• 4-Down output
• Volcano's output
• Volcanic stuff