Element and Axis
Dirtamancy is Stuffamancy, the magic of Matter. It is aligned to the axis of Erf. So, Dirtamancy is concerned with Stuff on Erf; specifically, rock, dirt, and crap. Commander I. Heartly Noah June 3 2009
The page mentions that a bonus to mineral golems led by a dirtamancer is "unusual"... but for all we know any caster that can create units (like a dollamancer) also gives them a bonus. We know that this is true for croakamancers and uncroaked.