Ancient dating techniques
Stratigraphy is the oldest of the relative dating methods that archaeologists use to date things.
Stratigraphy is based on the law of superposition--like a layer cake, the lowest layers must have been formed first.
His research culminated in proving that tree ring width varies with annual rainfall.
Not only that, it varies regionally, such that all trees within a specific species and region will show the same relative growth during wet years and dry years.
Seriation is thought to be the first application of statistics in archaeology. The most famous seriation study was probably Deetz and Dethlefsen's study Death's Head, Cherub, Urn and Willow, on changing styles on gravestones in New England cemeteries.
The method is still a standard for cemetery studies.
Secondly, annual rainfall is a regional climatic event, and so tree ring dates for the southwest are of no use in other regions of the world.
The first and simplest method of absolute dating is using objects with dates inscribed on them, such as coins, or objects associated with historical events or documents.Archaeologists use many different techniques to determine the age of a particular artifact, site, or part of a site.