Process of absolute dating
Very often historical evidence is found in layers and older layers are further down that the top layers.
For example: If an archaeologist is studying past civilizations, the archaeologist may be able to say that in a particular location the ruins of one civilization were found to have been built on another and so the layers unearthed in an excavation convey the sequence of historical occupations without revealing the actual dates.
Specialists in the field of astronomical research placed this solar eclipse as on 15 June 763 B. The Almanac belonging to Maya culture of Central America helped in dating several important sites accurately on the basis of astronomy.
Clay tablets found in West Asia contain inscriptional evidence with regard to the occurrence of a solar eclipse.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.In such cases subjective element cannot be ruled out.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.