Sedimentary rocks are rocks that are formed by the deposition of material at the Earth's surface and within bodies of water (e.g. sandstone.) Metamorphic rocks are denoting rock that has undergone transformation by heat, pressure, or other natural agencies (e.g. marble.) Igneous rocks are rocks that are formed through the cooling and solidification of magma or lava (e.g. obsidian.) Stratification is the layering of rocks on earth.
The age of some landformscan be determined by counting the layers of the rock because over time the rock receives layers and using fossils, scientist can determine when that dinosaur was alive and compare it to where the fossil was found inside of the rocks layers.
Usually, younger rock layers will be on top of older layers but if an older layer of rock is deposited on top of a younger layer of rock that would not be true. Living organisms can shape landforms by mining, building, blowing up rocks, and clearing other earth made features.