Question

How are fossils formed? Describe In brief, two methods determining the age of fossils?

Answer 1

The dead organisms like animals or plants have remained in the earth and they get preserved are called fossils, the dead remain not decomposed by the microbes. They are formed due to burying, continuously and not properly decomposed over a time.

Complete answer:
Fossils are the preserved remains of those plants or animal organisms that once existed in the remote past now they have gone extinct and they are found in the crust of the earth. The researcher used to study those fossils to know about past animals and their lives. Extinct prehistoric organisms buried or trapped under resin of the tree, the lava of the volcanoes etc.

The two methods are used to determine the age of fossils:-
1. Relative dating:- In which, if fossils are found in sedimentary rock by the accumulation of a layer of deposits, if fossils are closer to the earth surface in the crust it is said to be a younger fossil as compared to those which are found deeper in the earth crust.
2. Radiometric dating:- in this, the age of fossils is distinguished by the presence of radioactive isotopes and examine it chemically. The carbon dating method is used, carbon-14 is checked and used for radiometric dating.
Fossils are used to study the animal and plants lineage and linkage to know the evolutionary relationship. It also helps to know about the prehistoric animal habitat or environment.

Note: The completely dead organism may form fossil fuel which we use as fuel today in the production of electricity, in automobiles and thermal power plants and many more places. Fossils fuel comes in the form of coal, petrol and gases, which act as an energy source.