Use of carbon dating in archaeology
Several sets of rings from different trees are matched to build an average sequence.
Subsequently, overlapping series of average sequences from trees that died at different times and come from various sources (ie, the wood of historic buildings, archaeological and fossil woods) are used to build a chronological sequence covering several hundred years which becomes a reference.
On the other hand, absolute dating includes all methods that provide figures about the real estimated age of archaeological objects or occupations.
These methods usually analyze physicochemical transformation phenomena whose rate are known or can be estimated relatively well.
The bones were buried under (and are therefore older) a layer of ash that resulted from a volcanic eruption dating back to 7000 years BP (Before Present; "present" indicates c. Subsequently, radiocarbon dating, an absolute dating technique, was used to date the bones directly and provided a date of 8250 BP, showing how useful the combined used of relative and absolute dating can be.
In this case, even if the foundation of the building is found in the same stratigraphic level as the previous occupation, the two events are not contemporary.An initial reading dates the specimen which is then calibrated by considering this date and its correspondence with the measurable level of carbon 14 stored over time in the growth rings of certain tree species, including redwood and pine bristol.The results of radiocarbon dating are expressed in years and include a time range (eg, 630± 60 BP).Indeed, some items whose exact or approximate age is known are called "diagnostic artifacts." Examples of such objects include very specific stone tools, different pottery styles, objects that belong to a specific period (eg, the historic period or the French regime), coins with a production date, or other items bearing a trademark and whose history can be traced in historical records.Their presence on archaeological sites is used to date the soil layers and the objects and events they are associated with and thus contributes to refine the chronology of sites.
Search for use of carbon dating in archaeology:
Indeed, carbon 14 (14C) is formed from the reaction caused by cosmic rays that convert nitrogen into carbon 14 and then carbon dioxide by combining with carbon 12 (12C) and carbon 13 (13C ), which are stable carbon isotopes.