How are fossils formed? Describe, in brief, two methods of determining the age of fossils…
Fossil Formation: When organisms die, their bodies will decompose by action of microorganisms in oxygen and moisture. Sometimes in the lack of oxygen, moisture, their body does not decompose completely and is preserved as fossil with passage of time in the rocks. In several cases, soft parts of organism get decomposed and hard part as bones become fossil. Sometimes even the soft parts such as leaf remain preserved as fossils in form of their impressions inside rocks.
Methods to determine age of fossils :
There are two Methods as:
- Relative Method : Fossils which occur in layers closer to surface of earth are more recent. Fossils which are found in deeper layers are older ones.
- Carbon Dating : Fossils were once living objects and all living objects contain some carbon-14 atoms that are radio-active. When a living object dies and forms fossil, its carbon-14 radioactivity goes an decreasing gradually. Age of a fossil is found by comparing carbon-14 radioactivity left in fossil with carbon-14 radioactivity found in living objects today.