Deep Magic Volume 2 (p.174)
Earth Glide
3-level Transmutation
Casting Time: 1 action
Range/Area: 30 ft.
Components: Verbal, Somatic, Material
Materials: a piece of a creature that has teh Earth Glide trait
Duration: 1 hour
Damage/Effect: Movement
This spell grants up to ten willing creatures you can see within range the ability burrow through nonmagical, unworked earth and stone for the duration. Each target gains a burrowing speed equal to half its walking speed. While burrowing, an affected target doesn’t disturb the material through which it moves. If the duration ends with an affected target within unworked earth or stone, the spell carries the target to the surface at a rate of 60 feet per round.
Available for: Druid, Ranger, Sorcerer, Wizard