Archaeological dating isotopes
Plankton absorbs, Carbon-14 from the ocean much like terrestrial plants absorb Carbon-14 from the air.Since plankton is the foundation of the marine food chain, Carbon-14 is spread throughout aquatic life.
One good example would be the elevated levels of Carbon-14 in our atmosphere since WWII as a result of atomic bombs testing.Looking at the graph, 100% of radiocarbon in a sample will be reduced to 50% after 5730 years.In 11,460 years, half of the 50% will remain, or 25%, and so on.In a stratigraphical context objects closer to the surface are more recent in time relative to items deeper in the ground.Although relative dating can work well in certain areas, several problems arise.
Search for archaeological dating isotopes:
Long tree-ring sequences have been developed throughout the world and can be used to check and calibrate radiocarbon dates.