The 402 km long feature is a normal fault situated near the equator and running perpendicular to it. Rousillon Rupes has only few crater superimposed on it, which also implies its young age. The scarp was first imaged by Voyager 2 spacecraft in January 1986. (wikipedia entry)
A rupes is a scarp. On Titania they are named after female Shakespearean characters, places.
Sorry, there hasn't been a good map made for this world yet :(