Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Type of rock is limestone.
Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". Type of rock is marble.
Igneous rock is formed through the cooling and solidification of magma or lava. Type of rock is Obsidian.
Stratification:the formation of layers (strata) in which objects are found.
You can know because thge thinkness of the rock, because the thicker it is the younger it is because after a while the rock will wear down from the weather after time.
My hypothesis is that, the only way that an older rock end up on a younger rock is is you flip it upside down because, theirs no possible way for a older rock to grow on top of a younger rock or just simply being on top of the younger rock.
After time rocks have living things like moss that form on them. There is a way that living organisms can grow on them by simply being on the ground, after being on the ground moss and other organism can grow all over them because they need sunlight.