Quiz/Review• Get out a small piece of paper and put your

name on it. • When the bell rings,

the quiz will begin.

Question 1

• What are mass movements?

Question 2

• Name 2 types of mass movements.

Question 3

• What is one major cause of a landslide?

Answers

1) Large area of earth moved by gravity down a slope.

2) Slump, Slide, Fall or Flow3) Increase in water or slope

Mass Extinctions

Geologic Time Scale

• Earth was formed 4.6 BYA (billion Years Ago)

• How do we know this? • How old is the oldest rock

on Earth?– (look at your ESRT!)

Geologic timeline

Mass Extinctions

• These are events where most or a lot of living things on Earth were killed.

• To go Extinct means to have a whole species die and nothing is left living from that species.

Causes of mass extinctions

• Meteor impacts• Global Warming• Oxygen levels• Sea level change• Storms• Volcanic eruptions• Possible many more things… can you think of

something?

5 Major mass extinctions• Cretaceous (65mya) – 62% loss of species caused by impact and flood basalts

• Triassic (210mya) – 65% loss of species caused by impact and flood basalt.

• Permian (250mya)– 90% loss of species caused by impact, flood basalts, & global

warming.• Devonian (365mya)– 72% loss of species caused by impact.

• Ordovician (445mya)– 65% loss of species caused by ice age and sea level fall (still

debated)

Historic Mass Extinctions• One famous one is the K-T extinction.– Cretaceous and Tertiary periods– Where the dinosaurs died.

• Now?? Humans?– Global Warming– Sea level rise– Changing CO2 level– Loss of resources