Draw raw molten rock to the surface and make it flow as though it has purpose. It deals 4d6 fire damage to each creature in a 25' line up to 50' that fails a Constitution save and half this on a success. Creatures that end their turn in this area reroll the save. This lava ignites all unattended objects, and plants in it's path. The line for the flow can increase to 300' if cast down a steep incline and may change course at the DM's discretion.
Nivis Casus Liquefacta Massa