There are 3methods to determine age of fossils stratigraphy,biostratigraphi,radiomentry
Answers
stratigraphy-
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has two related subfields: lithostratigraphy (lithologic stratigraphy) and biostratigraphy (biologic stratigraphy).
Stratigraphy:
The earth underground is divided into several layers based on the zoological time.The layer that is found above was a recently formed one and the layer that is found much below was formed long back . The age of the Fossil obtained during excavation is determined by the stratified layer in which it was present i.e. the depth in which the fossil was found.
Radiometry:
However the most used technique is radiometry where radioactive isotopes are used.Every radioactive element undergoes decaying process.The time taken for a radio active element to decay into half of its original amount is termed as half life.
The value of half life is fixed for any particular element.By measuring the amount of radioactive decay of the element in the fossil one can determine the age of the fossil.
Several techniques are used:
- C14
- Lead and Uranium
- Argon and Potassium
- Rubidium and Strontium (to date oldest fossils)