Carbon 14 dating anthropology
The Mayan calendar used 3114 BC as their reference.
More recently is the radiocarbon date of 1950 AD or before present, BP.
For example, Christian time counts the birth of Christ as the beginning, AD 1 (Anno Domini); everything that occurred before Christ is counted backwards from AD as BC (Before Christ).
The Greeks consider the first Olympic Games as the beginning or 776 BC.
The Muslims count the Prophet’s departure from Mecca, or the Hegira, as their beginning at AD 662.
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.
Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: it is absorbed from the air by green plants and then passed on to animals through the food chain.