Which process is responsible for changing the composition of rock?

Answer: The reason for changing the composition of rock is chemical weathering. Chemical weathering can be defined as the change in the chemical composition of the rock by the effect of oxidation, hydrolysis, solution.

Under the effect of these, the mineral in the rock changes. This process requires water, temperature and damp climate to take place.

Erosion, weathering, mechanical changes, chemical changes.

Really, any interaction can change the composition of a rock whether it be done by man or through nature.