A Law describes what will happen. A theory explains why it happens. A Why can never become a What. A What might be seen as a Why.
Newton's theory of gravity explained that there was an attraction between mass similar to the attraction due to electro static forces.
It turns out Newton's theory was wrong or at least incomplete. The Theory of Relativity gave an alternative explanation that is now generally accepted as the reason for the attraction between masses.
Newton's Law of Gravity remains true at least at normal speeds and masses found in the universe.
The Theory of Relativity did not change the law of Gravity as formulated by Newton.
The law of superimposition in geology might be considered as a part of a theory. The law of superimposition says that the geological layer on top is always the youngest. This becomes part of the theory of uniformtarism that everything happens by slow uniform processes that can be observed in the present. The law supports the theory.