FACT
If the rocks
surrounding a fossil
are distorted and
squeezed by
geological forces, it
will result in
distortion of the
fossils within them.
- The mineral-rich water enters the hollow, and crystallises to create a natural cast of the
original organism. Otherwise the minerals slowly seep into the skeleton, changing its
chemical composition and making it capable of surviving for a long time. - Over many millions of years, rock that was once buried rises again to the surface and
is eroded away, exposing the fossils.
Fossilisation is very rare and only happens when a plant or animal dies in exactly the right
circumstances. Usually, animal corpses are eaten by other animals or decomposed by bac-
teria before fossilisation can occur. Even hard parts like bones and shells are eventually
destroyed through erosion and corrosion.Methods of dating fossils DUMMY
We have learnt how fossils are formed over geologic timescales. In this section we will learn
how we determine the age of a fossil in order to understand the various periods of life’s
history. There are two methods of dating fossils:320 11.2. Representations of life’s history