Limitations for using carbon 14 dating
Scientists attempt to check the accuracy of carbon dating by comparing carbon dating data to data from other dating methods.Other methods scientists use include counting rock layers and tree rings.However, there are a number of other factors that can affect the amount of carbon present in a sample and how that information is interpreted by archaeologists.
Radiocarbon dating was the first chronometric technique widely available to archaeologists and was especially useful because it allowed researchers to directly date the panoply of organic remains often found in archaeological sites including artifacts made from bone, shell, wood, and other carbon based materials.
For example, rootlet intrusion, soil type (e.g., limestone carbonates), and handling of the specimens in the field or lab (e.g., accidental introduction of tobacco ash, hair, or fibers) can all potentially affect the age of a sample.
Bioturbation by crabs, rodents, and other animals can also cause samples to move between strata leading to age reversals.
This process of decay occurs at a regular rate and can be measured.
By comparing the amount of carbon 14 remaining in a sample with a modern standard, we can determine when the organism died, as for example, when a shellfish was collected or a tree cut down.This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers.