GEOLOGY

Detailed explanation-1: -After the organism has been buried, more sediment, volcanic ash or lava can build up over the top of the buried organism and eventually all the layers harden into rock (they become ‘lithified’).

Detailed explanation-2: -Unfortunately, since the fossilization process takes at least ten thousand years, it is not particularly easy to study.

Detailed explanation-3: -David says, ‘It can take millions of years, but gradually fossils become exposed at the surface where we can find them. ‘Because of how they form, fossils occur in sedimentary rocks. So if you’re going fossil hunting, that’s where you should look.

Detailed explanation-4: -The process of petrification happens underground, when wood is buried by sediment and deprived of oxygen, thereby preserving it. Then, water containing minerals flows through the sediment, depositing minerals in the cells. As the cells the decay, the remaining minerals form a mold made of stone.