Start Methods of chronometric dating

Methods of chronometric dating

By cross-linking core samples from living and dead trees, a master sequence of annual tree-ring widths can be compiled.

Stratigraphic dating is based on the principle of depositional superposition of layers of sediments called strata.

This principle presumes that the oldest layer of a stratigraphic sequence will be on the bottom and the most recent, or youngest, will be on the top.

It does not, however, allow one to independently assign an accurate estimation of the age of an object as expressed in years.

Zircon and baddeleyite incorporate uranium atoms into their crystalline structure as substitutes for zirconium, but strongly reject lead.

However, the longer bristlecone pine sequence is of little value except for cross-checking the reliability of other dating techniques because logs of this species are rarely found in association with ancient humans.

It is based on the fact that amino acids (the building blocks of all proteins) exist in two mirror image forms, both of which otherwise have the same chemical structures.

The L-amino acid molecule form has an extension to the left, while the D-amino acid form has an extension to the right.