Fossils #6

Question 1

Whats the origin of prokaryotic life

Answer 1

3.5 billion years

Question 2

How long ago was the formation of earth

Answer 2

4.57 billion years ago

Question 3

How long ago was the Big Bang

Answer 3

13.7 billion years ago

Question 4

What do fossils show

Answer 4

• transformed body parts
• activity (‘trace fossils)- burrows or footprints
• preserved remains (‘sub fossils)- shells or remains in amber
• organic chemicals- any body part

Question 5

How are fossils formed

Answer 5

By a series of unlikely events
1. Soft parts are destroyed (eaten or degraded)
2. Remains must become buried in sediment at the bottom of a water column (only found in sedimentary rock)
3. Per mineralization- minerals fill tiny pores and spaces in an organisms remains turning them to stone
4. Exposure- must be found either by tectonic processes or lost forever

Question 6

What are igneous, sedimentary and metamorphic rock found in

Answer 6

Igneous- volcanoes
Sedimentary- under water
Metamorphic- under ground

Question 7

How can you date fossils

Answer 7

Radio carbon dating
Volcanic ash

Question 8

How do you date fossils through radio carbon dating

Answer 8

• 5730 years after death 1/2 the C14 —> N14
• can work out date of death by examining the ratio
• only fossils up to 40,000 years old

Question 9

How is volcanic ash used to date fossils

Answer 9

• many sediment contain volcanic ash (tephra)
• potassium and argon
• decay more slowly than C14 fossils older than 100,000