However, the assumption of contemporaneity may not always be correct.
This is due to the fact that one or both of the objects may have been moved or redeposited into a different location.
Consider a lake that dries out or somehow contains older sediments that are washed into it.
Prior to the availability of radiocarbon dates (and when there is no material suitable for a radiocarbon date) scientists used a system of relative dating.Based on the information presented in the lecture, students should be able to rank the images of island and volcanic processes from youngest to oldest.Their performance in this task is the assessable product.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.
For instance, if we find a fossil bone below the strata 3 rock level shown above, we assume that the animal most likely lived at a time before that layer was formed.