Bone dating methods
Stratigraphic dating remains very reliable when it comes to dating objects or events in undisturbed stratigraphic levels.
For example, the oldest human remains known to date in Canada, found at Gore Creek, have been dated using soil stratification.
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.
Typology Typology is a method that compares reference objects in order to classify them according to their similarity or dissimilarity and link them to a specific context or period.
This technique is frequently used when it is impossible to make use of absolute dating methods; it generally allows archaeologists to identify the period to which a cultural site or object belongs, without specifying the date of occupation.
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.
These methods usually analyze physicochemical transformation phenomena whose rate are known or can be estimated relatively well.
Radiocarbon Dating Radiocarbon dating is the most widely used dating technique in archaeology.
It relies on a natural phenomenon that is the foundation of life on earth.
Subsequently, the calibration of that date provides a time interval where the event or object being dated can be situated (eg, 1275-1425 AD).
Radiocarbon dating, however, can only be used for dating objects that are less than 50 000 years.