Science Common Sense

1556 - Why can fossils be used as auxiliary tools for relative geological age comparison of strata?

Fossils can be used to compare the ages of rocks (strata) because they contain the remains of ancient plants and animals that lived during specific time periods.

Here's how it works:

1. Fossils of the same type are found in different rocks in different places.
2. We know that the same type of fossil can only exist during a certain time period, like a specific type of dinosaur.
3. If the same type of fossil is found in two different rocks, it means those rocks were formed during the same time period.
4. By looking at the fossils found in different rocks, we can compare the ages of the rocks and say which one is older or younger.

This is like finding a picture of a dinosaur in two different books. If the dinosaur is the same, it's likely that the two books were printed around the same time. Similarly, if the fossils are the same, the rocks were formed around the same time.