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

• When did the last major eruption of Mt. St. Helens occur?

Question 2

• What killed most people in the major eruption of St Helens.

Question 3

• What causes a major landslide?

Answers

1) 19802) Lahar, pyroclastic flow, flooding, ash3) Slope, precipitation, human impact

Mass Extinction Cretaceous–Paleogene extinction (K-T)

What killed the dinosaurs?

(Formally called the Cretaceous-Tertiary extinction)

MapsMeteor impact 65.5 million years ago.

What is…A Meteor impact in Mexico 65.5 million years ago.

Killed 65-70% of all species on Earth.

90% of everything ever alive is now extinct! Extinctions are

common.

Five major extinctions in the past and many smaller ones.

When…

Earth is 4.6 Billion Years old.

Life on Earth began in the Paleozoic

(570 million years ago)

Dinosaurs were present on Earth

around 245 million years ago and lived

for about 180 million years.

Humans have only been on Earth for

maybe 10,000 years!

Time line

Very controversial!

Some say fast (few years) some say slow (millions

of years)?!

The fossil record is incomplete, so difficult to

say something is present or not.

What causes this event?

Meteor (widely accepted)

Volcanism (flood basalts)Deccan Traps (dark purple)

Climate ChangeAtmospheric changes from other

causes.

Sea level change Sea level fell after 65 mya

Mega-TsunamiDeposits of sea sediments in mountains of Mexico

Who is affected?Marine Invertebrates - 60% species extinct.

Fish - 80% survived

Terrestrial Invertebrates – Not determined

Plants - 57% plants extinct

Amphibians – Most survived

Mammals -

Reptiles – Almost all species become extinct.

Two major survivors

testudines - turtles

lepidosaurs – lizards and snakes.

FactsAll current data and theories are based off of fossil evidence.

The K-T boundary is identifiable in North America:

By lack of ferns before, but abundant after.

Hell creek, Montana

Pollen levels in rocks and ice

Hells creek formation

What If...5 previous major mass extinctions

Some say we are in one now?

Climate change

Sea level change

Loss of resources

Over population

Works Cited

http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event

http://science.nationalgeographic.com/science/prehistoric-world/mass-extinction/

http://www.msnbc.msn.com/id/35712419/ns/technology_and_science-science/t/rock-solid-case-asteroid-killed-dinosaurs/

http://www.staff.science.uu.nl/~rutte101/stuff/manicouagan/extinctions.png