In such cases subjective element cannot be ruled out.But, for a single culture site the method is quite reliable.Clay tablets found in West Asia contain inscriptional evidence with regard to the occurrence of a solar eclipse.
The types and forms or shape of these pots and also the antiquities under go evolutionary changes in cource of time, It is further assumed that all living animals derive body material from the plant kingdom, and also exhibit the same proportion of C-14 material.
Therefore as soon as the organism dies no further radiocarbon is added.
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.
The quantity of the C-14 remaining is measured by counting the beta radiation emitted per minute per gram of material.
Modern C-14 emits about 15 counts per minute per gram, whereas Carbon-14 which is 5700 years old, emits about 7.5 counts per minute per gram.
This dating method is also known as Archaeological Dating or Historical Chronology. These methods were relied on especially prior to the introduction of scientific methods of dating.
But, even when the scientific methods of absolute dating are available, this method of dating has not lost its importance, as many a time we have to depend solely on relative dating.
Antiquities and potteries of Roman origin were found in association with the finds of Indian origin.
With the aid of these dated imports it was possible to date the associated Indian objects to the first two centuries A. Similarly NBP and PGW has helped in fixing the chronology of numerous sites. Sometimes dates are also obtained with the assistance of astronomy.
Quite convincing dates are sometimes arrived at by importing parallels from other contemporaneous cultures.