AD&D 2nd Edition

Range: 10 yards/level
Components: V, S, M
Duration: Special
Casting Time: 5
Area of Effect: 20 ft cube/level
Saving Throw: None 

This spell turns natural rock of any sort into an equal volume of mud. The depth of the mud can never exceed half its length or breadth. If it is cast upon a rock, for example, the rock affected collapses into mud. Creatures unable to levitate, fly, or otherwise free themselves from the mud sink at the rate of 10 feet per round and suffocate, except for lightweight creatures that could normally pass across such ground. Brush thrown atop the mud can support creatures able to climb on 5top of it, with the amount of brush required subject to the DM’s discretion. The mud remains until a dispel magic spell or a reverse of this spell, mud to rock, restores its substance-but not necessarily its form. Evaporation turn the mud to normal dirt, at the rate of 1d6 days per 10 cubic feet. The mud to rock reverse can harden normal mud into soft stone (sandstone or similar mineral) permanently unless magically changed. The material components for the spell are clay and water (or sand, lime, and water for the reverse).