Question

What is the difference betwee epeirogeny and orogeny?

Answer 1

Orogenic movements are Mountain building movements whereas Epeirogenic movements are Continent building movements. 3. In Orogenic movements crust moves in a tangential direction causing folding or faulting.    In the Orogenic process, the crust is severely deformed, whereas in the Epeirogenic process there may be a simple deformation.  

Answer 2

Epeirogeny ("EPP-ir-rod-geny") is strictly vertical movement of a continent rather than horizontal movement that compresses it to form mountains 
And Orogeny is a process in which a section of the earth's crust is folded and deformed by lateral compression to form a mountain range