What geological feature is formed by the erosion of a sea cliff?

The geological feature that is formed by the erosion of a sea cliff is a wave cut platform. This feature occurs as waves continually crash against the cliff face, leading to the erosion of the rock. Over time, this process creates a gently sloping area at the base of the cliff, which is the wave cut platform.

As wave action continues, it removes material from the bottom of the cliff and may also undermine the cliff itself, causing it to eventually collapse. The platform is typically exposed at low tide and can be a significant feature along coastlines where sea cliffs are prevalent.

Caves and arches may also form as a result of erosion processes but typically involve more complex interactions with geological structures. Stalactites, on the other hand, are formed in caves through the deposition of minerals from dripping water and are not related to sea cliff erosion at all.