The test is used mainly in association with the fluorine test and radiometric assay, as in the cases of Piltdown and Swanscombe Man. The basis of cross-dating is the occurrence of finds in association.The assumption is that a particular type of artifact, for example a type of sword, when found in an undated context will bear a similar date to one found in a dated context, thus enabling the whole of the undated context to be given a chronological value.Aspartic acid is the compound most often used because it has a of 15,000-20,000 years and allows dates from 5,000-100,000 years to be calculated.However, racemization is very much affected by environmental factors such as temperature change.Clay and rocks contain magnetic minerals and when heated above a certain temperature, the magnetism is destroyed.
and which give the result in calendar years before the present, or B. Most of these techniques produce results with a techniques do not.
The method is based on the assumption that typologies evolved at the same rate and in the same way over a wide area or alternatively on assumptions of diffusion.
Many of the chronologies constructed before the advent of showed some of the links established by cross-dating to be invalid, so the method has become somewhat discredited.
The technique is based on the principle that cations of certain elements are more soluble than others; they leach out of rock varnish more rapidly than the less soluble elements, and their concentration decreases with time.
A cation is an ion carrying a positive charge which moves toward the negative electrode/cathode during electrolysis.
Chronometry applies to electronic devices, while Horology refers to mechanical devices.