Complex sentence: The main massif of Tohil Mons has ridges and grooves, which indicate the presence of materials that have been tectonically displaced, including younger mottled crustal materials that were displaced during mass wasting processes.
Split into simpler sentences: The main massif of Tohil Mons is characterized by ridges and grooves, which indicate materials are present which have been tectonically displaced. This includes younger mottled crustal materials that were also displaced during mass wasting processes.