Related Clues:

• A fissure in the earth's crust
• eg Vesuvius
• eg Mount Etna
• Accountant entering book number causes upheaval
• Performing on vocal my output is hot stuff
• A burning issue may arise from it
• Left in very old tin, old type of firework
• Mount Rainier, e.g
• Peru's El Misti, e.g
• Pyroclastic flow source
• Cool van travelling to hot mountain
• Coal, no scuttles? After five it's probably covered in ash
• Lava spewer
• Etna, for example
• One potentially explosive book half concealed by accountant, isn't it?