What is the state of matter when Ocean waves and sand erode a sea cave in a solid rock cliff?

The state of matter involved in the erosion of a sea cave in a solid rock cliff primarily includes solid and liquid. The solid state refers to the rock cliff itself, while the liquid state is represented by ocean water, which exerts force on the rock through waves. This interaction leads to physical weathering, where the solid rock is gradually worn away by the movement of the liquid water and the abrasive action of sand.