I've been trying to pin down the Tier formulas for some of the geo spells lately and with some of the data that Kumbai posted earlier in the thread, I believe I pinned down the equation for Refresh:
Floor(1+(Combined Skill/180)) + Geomancy Skill
Indi/Geo Refresh
Code:Skill Base Dunna Idris ----------------------------------------------- 0-179 1 6 11 180-359 2 7 12 360-539 3 8 13 540-719 4 9 14 720+ 5 10 15