Absolute or radiometric dating
any method of determining the age of earth materials or objects of organic origin based on measurement of either short-lived radioactive elements or the amount of a long-lived radioactive element plus its decay product.
A method for determining the age of an object based on the concentration of a particular radioactive isotope contained within it.
In 1979, Desmond Clark said of the method “we would still be foundering in a sea of imprecisions sometime bred of inspired guesswork but more often of imaginative speculation” (3).
Radiocarbon dating may only be used on organic materials.
Today, the radiocarbon-14 dating method is used extensively in environmental sciences and in human sciences such as archaeology and anthropology.
It also has some applications in geology; its importance in dating organic materials cannot be underestimated enough.
For inorganic matter and for older materials, isotopes of other elements, such as potassium, uranium, and strontium, are used.Dendochronology This method of dating is based on the number, width, and density of annual growth rings of long-lived trees.A master tree-ring index has been constructed in the southwestern United States for the Douglas fir and bristlecone pine.Although development of radiometric methods led to the first breakthroughs in establishing an absolute time scale, other absolute methods have limited applications.Chief among these are dendochronology, varve analysis, hydration dating, and TL dating.