Advantages and disadvantages of relative dating
Dating is a topic which can enrich the curricula of analytical chemistry.C to 1000 BC) whereas relative methods tell something about the age of an object or event in relation to another (for example the stratigraphy of a geological site allows distinguishing between younger, older or the same age).
Relative (or indirect or derivative) dating provides a time interval and organizes events or materials in time series without fixing a zero time of the calendar.This requires to have a clock, i.e., a suitable procedure for measuring time and to know the zero-setting.The zero setting, for instance the death of a living organism in radiocarbon dating, is the event defining the initiation of the time-counting process.By the same reasons, biological molecular clocks will be only briefly commented.Overall, physical and chemical methods of dating can be seen as analytical methods and hence submitted to the usual rules regarding the so-called analytical properties: accuracy and precision, sensitivity, selectivity, repeatability, reproducibility, robustness, security, traceability, etc. Of particular importance in the analytical process are the steps of sampling (representativity and integrity of the sample) as well as the operations of calibration and analysis of errors.In favorable cases, different methods of dating can be combined (for instance, radiocarbon dating of ancient papyrus and astronomical data contained in the same) to obtain chronological information.
Of course, the sources of information for dating can be diverse.
In general, the application of dating techniques involves a measurable time-dependent quantity and an event which determines the start of the time-counting.
It should be kept in mind that dating involves the introduction of a chronology into a given calendar, but not all the calendars are equivalent.
Constructing a sound chronology is an interdisciplinary task.
For instance, historical dating of Egyptian and Mesopotamian cultures based on astronomical records involves the knowledge of such diverse fields as astronomy, Semitic languages, Egyptian hieroglyphs, ceramics, and field archeology.
Here, the main physical and chemical methods will be presented following an operational criterion: their implementation as analytical methods directly addressed to date geological and/or archeological samples and related to analytical chemistry methodologies.