Relative chemical dating
Two broad categories of dating or chronometric techniques that archaeologists use are called relative and absolute dating.
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.
A geologic map or report typically is only a summary of investigations that frequently involve the collecting and processing of hundreds of rock samples, followed by the evaluation and interpretation of data from a variety of analytical techniques.
A relative age is the age of a fossil organism, rock, or geologic feature or event defined relative to other organisms, rocks, or features or events rather than in terms of years.
In such cases subjective element cannot be ruled out.
But, for a single culture site the method is quite reliable.
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.