Astronomical data have been applied in the study of geological ice ages by calculating the curves for major fluctuation of solar radiation.
Consequently, the chronology worked out for the geological deposits helped in dating the prehistoric tools found in these deposits. There are certain antiquities and potteries which by themselves have acquired a dating value.
Once a type has been classified by the aid of its context further specimen of the same type, even when found in isolation, can be assigned their place in terms of dates.
Association in simplicity can be illustrated by an example, at the port of Arikamedu near Pondicherry.
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.
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.
According to him a period of hundred years may be granted for the accumulation of a deposit of one and a half feet.
At that time the radioactive disintegration takes over in an uncompensated manner. only half the C-14 will remain after the half-life period.
In the disintegration process the Carbon-14 returns to nitrogen emitting a beta particle in the process.
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.