Methods dating artefacts
The half-life of C is approximately 5730 years, which is too short for this method to be used to date material millions of years old.
The isotope of Potassium-40, which has a half-life of 1.25 Billion years, can be used for such long measurements.
The deposit thus occurring forms layers depending on the nature of the material brought in by the people inhabiting the area.
According to this method, the upper deposits are younger and the lower deposits are older.
Basing on this principle, the cultural assemblages found in different layers can be assigned a chronological personality. In practice it is found that the mounds are disturbed9 by all sorts of pits and dumps.
For example, if the cultural contents of the lower deposit are Mauryan in character, appropriately this deposit may be assigned a date between 400-200 B. Similarly, if the cultural equipment of the upper deposit are of the Sunga period, this deposit has to placed between 200-73 B. Quite often, the archaeologist decided the change of stratum on the basis of the feed of the deposit.
This usually requires what is commonly known as a "dating method".
b) Absolute These methods are based on calculating the date of artefacts in a more precise way using different attributes of materials.
This method includes carbon dating and thermoluminescence.
Several dating methods exist, depending on different criteria and techniques, and some very well known examples of disciplines using such techniques are, for example, history, archaeology, geology, paleontology, astronomy and even forensic science, since in the latter it is sometimes necessary to investigate the moment in the past in which the death of a cadaver occurred.
Relative dating methods are unable to determine the absolute age of an object or event, but can determine the impossibility of a particular event happening before or after another event of which the absolute date is well known.
In this relative dating method, Latin terms ante quem and post quem are usually used to indicate both the oldest and the most recent possible moments when an event occurred or an artifact was left in a stratum.