This is the only type of techniques that can help clarifying the actual age of an object.
Absolute dating methods mainly include radiocarbon dating, dendrochronology and thermoluminescence.
On the other hand, absolute dating includes all methods that provide figures about the real estimated age of archaeological objects or occupations.
These methods usually analyze physicochemical transformation phenomena whose rate are known or can be estimated relatively well.
Several sets of rings from different trees are matched to build an average sequence.
Subsequently, overlapping series of average sequences from trees that died at different times and come from various sources (ie, the wood of historic buildings, archaeological and fossil woods) are used to build a chronological sequence covering several hundred years which becomes a reference.
The results of radiocarbon dating are expressed in years and include a time range (eg, 630± 60 BP).Stratigraphy Inspired by geology, stratigraphy uses the principle of the superposition of strata which suggests that, in a succession of undisturbed SOILS, the upper horizons are newer than the lower ones.Generally, each stratum is isolated in a separate chronological unit that incorporates artifacts.Finally, absolute dating is obtained by synchronizing the average sequences with series of live (and thus datable) trees and thus anchors the tree-ring chronology in time.Dendrochronology mainly uses softwood species that are sensitive to changes in growth conditions, while hardwoods show rather little variation in ring width.Stratigraphic dating remains very reliable when it comes to dating objects or events in undisturbed stratigraphic levels.