Answer:
relative dating
Explanation:
The fossils' age can be determined by using two methods: Absolute Dating and Relative Dating.
The "Relative Dating" examines the relationship between rocks and fossils in order to date certain objects. The correlation between things are checked according to the order of events in history and not according the the event's numerical age. The fossil record here is known as "index fossils." It becomes the basis for knowing the geologic period.
