Which geological process involves the wearing away of solid rock?

Erosion is the geological process that specifically involves the wearing away and removal of solid rock material. This process is driven by various natural forces, such as water, wind, ice, and gravity, which actively transport sediment away from its source. During erosion, pieces of rock and soil are dislodged and carried to other locations, leading to the alteration and sculpting of the landscape over time.

While all the options presented relate to geological processes, erosion is distinguished by its focus on the movement of material, contrasting with other terms. For instance, weathering refers to the breaking down of rocks into smaller particles but does not involve the movement of those materials. Metamorphism involves the transformation of existing rock types due to heat, pressure, or chemically active fluids, while deposition is the accumulation of sediment in a new location, which is a consequence of erosion rather than the process itself. Thus, the correct answer highlights the active removal and transport aspect inherent in the process of erosion.