How are fossils formed? Flashcards
Why do most plants and animals leave no remains when they die?
Soft parts like skin, hair, and organs are either eaten or decompose.
What happens to the hard parts such as shells or bones?
They get crushed, scattered, blown away or moved by water.
How long does it take for a fossil to form?
Millions of years.
To transfer to a fossil the seed, plant or animal needs to be buried very quickly. Where is this most likely to take place?
The river delta. A place where the river flows into the sea.
To transfer to a fossil the seed, plant or animal needs to be buried very quickly. Where is this most likely to take place?
The river delta. A place where the river flows into the sea.
Why is the river delta the most likely place?
Because sand and clay flow from the river into the sea. The creature or plants gets entombed in the clay which makes an imprint of the organism.
Where else can fossils sometimes be found and why?
The desert… as dead animals are buried quickly in the event of a sandstorm.
What is sediment?
Sediment is a layer of sand and clay particles and broken shells.
Describe how sediment eventually pushes fossils upward for us to find.
- Dead animals sink to the bottom of the sea.
- The animal is covered by sediment.
- New layers of sediment are added every year.
- The sediment with the animal remains petrifies.
- Hot rock folds the soil pushing it up.
- The earth erodes and fossils rise up.
What is petrified?
When pressure and heat make soil layers as hard as stone.
What is erosion?
The process by which wind and water gradually wear away a piece of earth.
