Methods of dating archaeological finds
Aluminum containers with screw caps are safe, but it is still best to consult the radiocarbon laboratory for the best containers of carbon dating samples. It is known that may minerals and natural glasses obsidian, tektites contain very small quantities of uranium. Handling with bare hands may add oil, grease, etc to the sample. This data help in obtaining and objective interpretation of dates.
Most trees produce a ring of new wood each year, visible as circles when looking at the cross section of a piece of wood. For earlier periods there are several problems. Labels attached to the packaging materials must not fade or rub off easily.
Relative techniques can determine the sequence of events but not the precise date of an event, making these methods unreliable. The mechanical strains produced as a result throughout the hydrated layer can be recognized under polarized light.
Charcoal is best material specially if derived from short live plants. These tracks disappear when the glass is heated above a critical temperature and fresh tracks formed in course of time.
The dating of obsidian artifacts is based on the fact that a freshly made surface of obsidian will absorb water from its surroundings to form a measurable hydration layer. Historians can tell what cultures thrived in different regions and when they disintegrated.
While collecting samples for radio carbon dating we should take utmost care, and should observe the following principles and methods. This method is based on the fact that the magnetic field of the earth is changing constantly in direction and proporationate intensity, and that these changes lead to measurable records. The magnetism present in the clay is nullified once the pottery, bricks or klins are heated above degree centigrade. This method of dating depends upon the measurements of detectable damage called tracks in the structure of glasses caused by the fission.
In either of the cases, it is still worthwhile to carefully consider why the radiocarbon dating results were deemed unacceptable. Timescale Radiocarbon dating takes time, and laboratories often have waiting lists so this factor must be considered. Therefore, it is better to collect samples with clean and dry stainless steel sclapels or squeezers. Therefore sampling should be done with such material only.
The first method was based on radioactive elements whose property of decay occurs at a constant rate, known as the half-life of the isotope. We have to fill the data sheets, which should be done at the time of sampling and should be submitted along with the sample to the dating laboratory. The sample-context relationship is not always straightforward. These water molecules then slowly diffuses into the body of the obsidian. The formation of rings is affected by drought and prosperous seasons.