Question

How r fossil formed? describe in brief two methods of determining the age of fossils?

Answer 1

Fossils were formed million of years ago when the dead bodies of plants and animals were buried inside the wetty soil. Over time it became fossil.

Age of fossils can be determined by :
(i) Carbon- dating- The number of CARBON 14 atoms are calculated which gives fossil's age.

(ii) Distance from the top layer of soil - Its distance from the earth crust can be used to determine its age as the oldest fossil will be buried at the deepest.

Hope it helps!

Answer 2

Fossils may be defined as the remains of the organisms which have been preserved in the form of molds or cast in rocks etc. since prehistoric ages.

When a plant or an animals dies, their remains falls on the ground. Over a period of time their body gets covered by sediments brought by rivers, winds etc. These sediments keeps on getting accumulated for over hundred of years and when that land gets eroded, the fossils can be seen clearly. Thus, the process of accumulation of dead remains of plants and animals for over hundreds of years results in the formation of fossils.

There are two components to this estimation of age of fossils.

Relative- If we dig into the earth and start finding fossils, it is reasonable to suppose that the fossils we find closer to the surface are more recent than the fossils we find in deeper layers.

Dating fossils- detecting the ratios of different isotopes of the same element in the fossil material.