R: Touch D: [sum] x rounds

You sing the old song of speleologic life, and all crystals, stalagtites, stalagmites and other calcite formations within earshot start to dance. All creatures can move through them without penalty, pushing them aside as if they were tall grass. You can end the spell at any moment, and all creatures crossing the formations will be trapped.

crystal + gap

From Coins and Scrolls’s Speleomage