What features suggest wheather erosion or deposition created a landform?

Not quite sure what you're asking, but erosion and deposition do create land forms. For example: erosion along the coastline may result in the formations of arches, stacks, stumps, wave cut platforms, caves, etc. Deposition, different amount of it and in certain areas, under the influence of either destructive or constructive waves, will form beaches - ones with a lot of beach, through a lot of deposition, or slopes beaches where destructive waves have crashed upon the beach. Hope this is what you're looking for.