uncommon earth transmutation 

Cast [>>] somatic, verbal

Range 60 feet; Targets 1 creature

Saving Throw Reflex; Duration 1 round

You tear open the ground then slam it shut. The target creature takes 2d6 bludgeoning damage with a Reflex save.

Critical Success The target is unaffected.Success The target takes half damage.Failure The target takes full damage, is flat-footed, and takes a –10-foot circumstance penalty to Speed.Critical Failure The target takes double damage and is flat-footed and immobilized. It can attempt to Escape against your spell DC. If it doesn't Escape, the target takes an additional 2d6 bludgeoning damage when the spell ends.

Heightened (+1) Increase the initial damage and additional damage by 2d6.

Secrets of Magic, page 200.