This power grants you access to a range of earth spells. Each rank gives you +10 range, +2 Ascendancy and +1 Power to each earth spell, and also increases the duration and stat bonuses of earth spell affects.
A single rank in this power will give you the Barkskin spell. At rank 4 you learn Summon Stone Maul. At rank 5 you learn Giant Growth. At rank 10 you learn Stoneskin.