Your SlideShare is downloading. ×
  • Like
Chapter 14.1: The Continental Drift Hypothesis
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.


Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Chapter 14.1: The Continental Drift Hypothesis


8th Grade Integrated Science Chapter 14 Lesson 1 on the Continental Drift Hypothesis. This is a short introduction to Alfred Weger and the current evidence used to support his theory. There is a short …

8th Grade Integrated Science Chapter 14 Lesson 1 on the Continental Drift Hypothesis. This is a short introduction to Alfred Weger and the current evidence used to support his theory. There is a short explanation of the fossil and rock evidence found.

Published in Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads


Total Views
On SlideShare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. The Continental Drift Hypothesis Chapter 14 Lesson 1 p494-500
  • 2. New Vocabulary • Pangaea (495) – The supercontinent that all continents today were once a part of • Continental Drift (495) – A hypothesis that suggests that continents are in constant motion on the surface of Earth
  • 3. Pangaea • Each year, North America moves a few centimeters farther away from Europe and closer to Asia. • Nearly 100 years ago Alfred Wegener began an important investigation to know whether Earth’s continents were fixed in their positions. – He proposed that all continents were once part of a supercontinent called Pangaea. – Over time Pangaea began breaking apart, and the continents slowly moved to their present positions. • Wegener proposed the hypothesis of continental drift, which suggested that continents are in constant motion on the surface of Earth.
  • 4. Evidence That Continents Move • The most obvious evidence for continental drift is that the continents appear to fit together like pieces of a puzzle. • However, scientists were skeptical, and Wegener needed additional evidence – 1. Apparent fit of the continents – 2. Fossil Correlation – 3. Rock and Mountain Correlation – 4. Past Climate Data
  • 5. Climate Clues • When Wegener pieced Pangaea together, he proposed that South America, Africa, India, and Australia were located closer to Antarctica 280 million years ago. • He suggested the climate of the Southern Hemisphere was much cooler at the time. – Glaciers covered most of these continents • Wegener studied the sediments deposited by glaciers in South America, Africa, India, and Australia. • He discovered glacial grooves, or deep scratches in rocks made as the glaciers moved across the land on neighboring continents today.
  • 6. Fossil Clues
  • 7. Fossil Clues • Animals and plants that lived on different continents can be unique to the continent alone. – Kangaroos are exclusive to Australia. Lions live in Africa but not S. America. – Because oceans separate continents, these animals cannot travel from one continent to another by natural means • However, fossils of similar organisms have been found on several continents separated by oceans.
  • 8. Fossil Clues • Fossils of a plant called Glossopteris have been discovered in rocks from South America, Africa, India, Australia, and Antarctica. • Evidence suggests these plants grew in a swampy environment. Therefore, the climate of this region, including Antarctica, was different than it is today – Antarctica had a warm and wet climate and changed drastically from 55 milllion years earlier when glaciers existed.
  • 9. Rock Clues • Wegener also observed that mountain ranges and rock formations on different continents had common origins. – Today geologists have determined that large- scale volcanic eruptions occurred on the western coast of Africa and the eastern coast of South America at about the same time hundreds of millions of years ago • These volcanic rocks are identical in both chemistry and age
  • 10. Rock Clues • The Caledonian mountain range in northern Europe and the Appalachian Mountains in eastern N. America are similar in age, structure, and composition. • If you place the continents together, these mountains would meet and form on long, continuous mountain belt.
  • 11. What is missing? • Wegener continued to support the continent drift hypothesis until his death in 1930 • His ideas were not widely accepted until nearly 4 decades later, because he could not explain how they moved • One reason scientists questioned continental drift was because it is a slow process • It was not possible for Wegener to measure how fast the continents moved – How could continents push their way through the solid rock of the sea floor? – However at that time, the world was only beginning to understand what the seafloor looked like. – It took many years after Wegener died before the evidence of plate tectonics hidden in the rifts on the seafloor to be discovered.