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.
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.
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.