Answer:
Fossils
Step-by-step explanation:
Ancient plants and animal formed into rocks called fossils.
A fossil can be defined as the mineral impression or remains of living organisms such as plants and animals that are prehistoric in nature.
A geologic column can be defined as a collection of rock layers that are typically grouped based on their relative ages in a descending order i.e from oldest to the youngest.
Generally, the layers of the rock that are found in various parts of the world are known to be different because they all comprises of distinct Earth's geological history (fossils).