This method is primarily applied to projectile points and ceramic vessels.
These present many characteristics that are used for comparing them, such as morphology and raw materials in the case of stone tools, and decorative techniques and motifs in the case of ceramics.
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.
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.
For those researchers working in the field of human history, the chronology of events remains a major element of reflection.
Archaeologists have access to various techniques for dating archaeological sites or the objects found on those sites.
The amount of carbon 14 remaining in the material to date is compared to a reference standard (ratio 14C/total carbon, 12C and 13C) to calculate the time elapsed since its occurrence.
A sample requires 10 to 20 grams of matter and usually consists of charred organic material, mainly charcoal, but bones (zooarchaeology) and shells can also be dated using this technique.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.Moreover, stratigraphic dating is sometimes based on the objects that are found within the soil strata.This approach helps to order events chronologically but it does not provide the absolute age of an object expressed in years.Relative dating includes different techniques, but the most commonly used are soil stratigraphy analysis and typology.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.