The Tannheim Mountains are part of the Northern Limestone Alps, whose folding began during the Alpide orogeny in the Lower Cretaceous about 140 million years ago and has not quite finished even today. In the wake of this mountain folding various nappes (Decken) of sedimentary rock (parts of the earth's crust broken off from the subsurface and pushed over one another) were stacked up and reach the surface as the Lechtal Nappe (Lechtaler Decke) in the area of the Kellenspitze. The summit and northern mountainside consist of Wetterstein limestone, whilst the southern flank comprises soft marl of the so-called Partnach beds . The rock of the Kellenspitze is very crumbly in places and relatively unattractive to climbers as a result.