Science definition for relative dating
Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation.
Index fossils are fossils that are known to only occur within a very specific age range.
In other words, we can say that in relative dating the archaeologist determines that which of the two fossil or the artifacts are older.
Contrary to this, absolute dating is the technique, using which the exact age of the artifacts, fossils, or sites are ascertained.
Using relative dating the fossil is compared to something for which an age is already known.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
In the field of Geology, dating is an important term as it is a technique through which evaluation regarding the age and period about the fossil, remains, the archaeologists do valuables and artifacts.
At first, there were not many methods of dating were available, but now with advancement in the technology, we mainly have two types of techniques to ascertain ages of ancient belongings.
If the fossil you are trying to date occurs alongside one of these index fossils, then the fossil you are dating must fall into the age range of the index fossil. In a hypothetical example, a rock formation contains fossils of a type of brachiopod known to occur between 410 and 420 million years.
Potassium-40 on the other hand has a half like of 1.25 billion years and is common in rocks and minerals.
This makes it ideal for dating much older rocks and fossils.
The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?