Thermo Luminescence (TL) Dating This method is based on the phenomenon of natural ionizing radiation inducing free electrons in a mineral that can be trapped in defects of the mineral’s crystal lattice structure.When trapped electrons escape as TL and are heated to a temperature below incandescence, the TL of a mineral such as quartz, can be recorded.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.It is clear then that absolute dating is based upon physical and chemical properties of artifacts that provide a clue regarding the true age.This is possible because properties of rock formations are closely associated with the age of the artifacts found trapped within them.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.
Counting and correlation of varves have been used to measure the age of Pleistocene glacial deposits.
This type of dating employs many dating techniques like atomic clocks, carbon dating, annual cycle methods, and trapped electron method.
Dendrochronology is another of the popular method of finding the exact age through growth and patterns of thick and thin ring formation in fossil trees.
Dendochronologists can use this index to date accurately events and climatic conditions of the past 3000-4000 years.
Varve Analysis This technique was developed by Swedish scientists in the early 20th century.
However, archeologists still require further information to find out the items that are oldest and those that are youngest in the order.