Download presentation
Presentation is loading. Please wait.
Published byMelvin Laurence Edwards Modified over 9 years ago
1
Quiz/Review Get out a small piece of paper and put your name on it. When the bell rings, the quiz will begin.
2
Question 1 When did the last major eruption of Mt. St. Helens occur?
3
Question 2 What killed most people in the major eruption of St Helens.
4
Question 3 What causes a major landslide?
5
Answers 1)1980 2)Lahar, pyroclastic flow, flooding, ash 3)Slope, precipitation, human impact
6
Mass Extinction Cretaceous–Paleogene extinction (K-T) What killed the dinosaurs? (Formally called the Cretaceous-Tertiary extinction)
7
Maps Meteor impact 65.5 million years ago.
8
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.
9
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!
10
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.
11
What causes this event? Meteor (widely accepted) Volcanism (flood basalts) Deccan Traps (dark purple) Climate Change Atmospheric changes from other causes. Sea level change Sea level fell after 65 mya Mega-Tsunami Deposits of sea sediments in mountains of Mexico
12
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.
13
Facts All 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
14
What If... 5 previous major mass extinctions Some say we are in one now? Climate change Sea level change Loss of resources Over population
15
Works Cited http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleo gene_extinction_event http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleo gene_extinction_event http://science.nationalgeographic.com/science/prehistori c-world/mass-extinction/ http://science.nationalgeographic.com/science/prehistori c-world/mass-extinction/ http://www.msnbc.msn.com/id/35712419/ns/technology _and_science-science/t/rock-solid-case-asteroid-killed- dinosaurs/ 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/manicouag an/extinctions.png http://www.staff.science.uu.nl/~rutte101/stuff/manicouag an/extinctions.png
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.