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.
" Serianne Worden (Columbia University) beams over a piece of pottery in the fill of an obsolete tank in the "Soap Factory." Nearly all of the industrial tanks we have excavated are adjacent to the threshold, in close proximity to the path of curious tourists. When possible, fractured pieces are rejoined in their original configuration, as was this platter held by Louise Ford (University of Bradford).
A crater in the city wall behind marks the point of impact one such ball may have made in 89 B. Burns is currently a doctoral student at University College London, where he is writing a dissertation on Roman warfare. All ceramic samples are carefully sorted, catalogued, illustrated, and studied by pottery specialists.
These methods usually analyze physicochemical transformation phenomena whose rate are known or can be estimated relatively well.
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.
Absolute dating is usually based on the physical or chemical properties of the materials of artifacts, buildings, or other items that have been modified by humans.
Absolute dates do not necessarily tell us when a particular cultural event happened, but when taken as part of the overall archaeological record they are invaluable in constructing a more specific sequence of events.