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Mass Extinction Cretaceous–Paleogene extinction _K-T_

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Mass Extinction Cretaceous–Paleogene extinction _K-T_ Powered By Docstoc
					               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) 1980
2) Lahar, pyroclastic flow, flooding, ash
3) Slope, precipitation, human impact
      Mass Extinction
      Cretaceous–Paleogene
         extinction (K-T)




           What killed the dinosaurs?

(Formally called the Cretaceous-Tertiary extinction)
            Maps
Meteor impact 65.5 million years ago.
                    What is…
 A
Ø Meteor impact in Mexico 65.5 million years ago.
ØKilled 65-70% of all species on Earth.
Ø90% of everything ever alive is now extinct! Extinctions are
common.
   ØFive major extinctions in the past and many smaller ones.
             When…
ØEarth is 4.6 Billion Years old.
 Life
Ø on Earth began in the Paleozoic
(570 million years ago)
ØDinosaurs were present on Earth
around 245 million years ago and lived
for about 180 million years.
ØHumans have only been on Earth for
maybe 10,000 years!
                   Time line
ØVery controversial!
  ØSome say fast (few years) some say slow (millions
    of years)?!




ØThe fossil record is incomplete, so difficult to
  say something is present or not.
        What causes this event?
ØMeteor (widely accepted)
ØVolcanism (flood basalts)
   ØDeccan Traps (dark purple)

ØClimate Change
   ØAtmospheric changes from other
   causes.

 Sea
Ø level change
   ØSea level fell after 65 mya

ØMega-Tsunami
   ØDeposits of sea sediments in mountains of Mexico
                Who is affected?
ØMarine Invertebrates - 60% species extinct.
ØFish - 80% survived
ØTerrestrial Invertebrates – Not determined
ØPlants - 57% plants extinct
ØAmphibians – Most survived
ØMammals -
ØReptiles – Almost all species become extinct.
   ØTwo major survivors
       Øtestudines - turtles
       Ølepidosaurs – lizards and snakes.
                            Facts
 All
Ø current data and theories are based off of fossil evidence.
 The
Ø K-T boundary is identifiable in North America:
    By
   Ø lack of ferns before, but abundant after.
   ØHell creek, Montana                    Hells creek formation

   ØPollen levels in rocks and ice
                     What If...
Ø5 previous major mass extinctions


ØSome say we are in one now?
  ØClimate change

  ØSea level change

  ØLoss of resources

  ØOver population
                    Works Cited

Ø http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Pale
  ogene_extinction_event
Ø http://science.nationalgeographic.com/science/prehistori
  c-world/mass-extinction/
Ø http://www.msnbc.msn.com/id/35712419/ns/technology
  _and_science-science/t/rock-solid-case-asteroid-killed-
  dinosaurs/
Ø http://www.staff.science.uu.nl/~rutte101/stuff/manicoua
  gan/extinctions.png

				
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posted:2/19/2014
language:English
pages:15