Deadly Lahar

(Complete Mage)

Conjuration [Earth, Fire]
Level: Druid 8, Sorcerer 8, Wizard 8, Wu Jen 8 (earth and fire),
Components: V, S,
Casting Time: 1 standard action
Range: 60 ft.
Area: Cone-shaped spread
Duration: Instantaneous
Saving Throw: Reflex partial
Spell Resistance: No

A rushing torrent of liquid rock bursts from the ground, washing over your foes.
You create a liquid landslide of molten-hot volcanic material.
All creatures in the area of the spell take 10d6 points of fire damage.
Additionally, those creatures are coated in a thick layer of the viscous substance, slowing them (as the slow spell) for the next 3 rounds and dealing an additional 5d6 points of fire damage per round.
A successful Reflex save reduces the initial damage by half and prevents the slow effect and the additional damage.