Fossils

Question 0

How are fossils created?

Answer 0

1. Animal dies
2. covered in sediments quickly after death
3. soft parts of animal decay, leaving only bones, teeth and shells. More sediments are laid down
4. the sediment slowly turns to rock, putting pressure on the animal and fossilising it.

Question 1

What is a fossil

Answer 1

Fossils are the preserved remains, impressions or traces of past life on Earth preserved in rock.

Question 2

Dating fossils (comparative and radioactive)

Answer 2

Comparative dating: is when geologists date fossils asked on the surrounding fossils in lower/higher bands of sediment. The further down the fossil is, the older it is.

Radioactive dating: is a more accurate measure of the age of a fossil. We do this by measuring the amount of radioactivity in the fossil by comparing the amounts of uranium and lead in it.

Question 3

Petrified fossils

Answer 3

The chemicals which make up bones and and other hard parts of ancient organisms are often replaced by minerals from the surrounding rock.

This process is called petrification and the organism is said to be petrified