However, relative methods are , which is that if there are layers of deposits, those laid down first will be on the bottom and those laid down last will be on the top. However, geological strata are not always found to be in a neat chronological order.
Wind and water erode strata and some areas are uplifted or even tilted.
can be used to tell us whether or not the animals they were from actually lived at about the same time.
This relative dating method is based on the fact that there are specific progressive chemical changes in skeletal remains that result from burial underground.
In other words, the biochemical clock that this method relies on runs at a different rate in different environments.