The surface feature of the Earth most likely formed by the process of erosion is a canyon.

Here's why:

* Erosion: The process of wearing away and transporting rock and soil by natural forces like water, wind, or ice.

* Canyons: Deep, narrow valleys with steep sides, often carved by rivers over long periods of time.

While other features like beaches, sand dunes, and deltas can also be formed by erosion, canyons are the most direct and dramatic result of erosive forces.

Let me know if you'd like to explore more about different types of erosion and the landforms they create!