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Alfred Wegener and Pangaea
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Alfred Wegener and the Continental Drift Theory
Introduction
You guys are probably thoroughly confused, right?
Earth is a complex, and immense field of study, and by analyzing the theories and works of geologist Alfred Wegener after this crash course, we hope you will develop a new understanding of Geologic history, and the change our planet undergoes.
Introduction
Fun Activity
Alfred Wegener
Who Am I?
Contributions and Life
His Contributions
Alfred Wegener was born on November 1, 1880, in Berlin Germany. He died in November 1930, in Greenland. He was a meteorologist and geophysicist. He went to the University of Berlin and got PHD in astronomy. While he was studying at the college, he found an interest in paleoclimatology. His first interests with Pangaea came when he noticed that Africa and South America had similar border lines, ones that could almost link up. He began looking into this idea, that all of the continents once created a “super-continent”
Continental Drift
This is a theory set forth in 1912 by Alfred Wegener, to explain how continents shift positions on Earth’s surface, and explained the similarities between rock formations and animal remains found of different portions of the Earth. It was a precursor to the modern day explanation of plate tectonics, which incorporates these ideas. Continental drift is the large scale, horizontal movement of continents during geologic time. When Wegener first proposed this theory, most of the geologist were "contractionist"; they thought rock formations were caused by Earth’s cooling and shrinking processes. However, his inability to come up with a reasonable mechanism made other scientists denounce the theory.
Fossils and Factual Evidence
From geologic formations at very specific parts of the world, and fossils of similar species found on different continents, much of the world's curiosities have been reaffirmed through the theory of Continental Drifting and Plate Tectonics.
Evidence
Analyze this Map; Why do you think the mountain ranges are located where they are located?
Mesosaurus Fossil/ Other Remains
The reptile Mesosaurus was a swimming reptile but could only swim in freshwater. However, it's remains were mostly found in South Africa and Eastern South America, giving support towards the Pangaea super continents and Continental Drift theory proposed by Wegener.
Other Fossil Evidence
Cynognathus and Lystrosaurus were land reptiles and were unable to swim. Cynognathus fossils are found only in South Africa and South America. While Lystrosaurus are only found in Antarctica, India, and South Africa.
Geologic Evidence
Grooves and rock deposits left by ancient glaciers are found today on different continents very close to the equator.
Geological Evidence
Pangaea
Scientist believe that about 245 million years ago, the continents were joined in a single large landmass known as Pangaea. Through the collision of the continents, mountains were formed, and there was a single large ocean called Panthalassa that surrounded the mega-continent. Therefore, Pangaea is not the continental drift, but instead just evidence for it.
Plate tectonics state that Earth’s lithosphere consists of large ridge plates that move apart, subduct or slip past one another. The pattern of the seafloor spreading postulates that super-continents and drifting has occurred several times in geologic history.
Pangaea Timeline
A large rift formed and Pangaea than began to break into two continents; Laurasia and Gondwana. Then the movement of Laurasia began to drift north and rotate and a new rift formed. At the same time, Gondwana also broke into two separate Continents. Pangaea is actually a quite recent formation of an enormous super continent due to continental drift.
Timeline of Pangaea
Pangaea: One Big Puzzle
Puzzling Pangaea
If we analyze a Map, we can see places where it seems that the continents could connect, as if they were connected before, but broke off.
Plate Tectonics
A more modernized concept, with the incorporation of Wegener’s theory of Continental Drift; however this theory incorporates a mechanism. Earth’s surface is covered by a series of of crustal plates, and the ocean floor is continually moving, regenerating, contracting and subducting. Underneath there is a mechanism of convection currents, which which move the plates in different directions. There are seven major plates on the lithosphere, Earth’s outermost area: the African, North American, South American, Australian, Eurasian, Antarctic and Pacific plates. The boundaries of the plates are divided into three types: crashing boundaries are known as the Convergent, pulling apart Divergent, and side sweeping Transform Boundaries.
Modern Day Theories
Three Types of Tectonic Boundaries
Illustrating Boundaries
The boundaries of the plates are divided into three types:
Crashing boundaries are known as Convergent
Boundaries pulling apart are Divergent
Side sweeping boundaries are known as the Transform Boundaries
Lesson Review
Who proposed the theory of Pangaea and Continental Drift?
What modern theory explains geological formations and movement of the Earth?
Which section of the Earth are the tectonic plates located upon?
Name the three types of plate boundaries.
Learning Activity
KAHOOT!
Assessment
https://play.kahoot.it/#/?quizId=90b347c6-679a-45e9-828b-70a003faceb2
Directions
Foldable
1. There is a piece of folded paper and a Ziploc bag full of continents on each one of your desks.
2. Position the continents like the first picture below:
3. Pull the folded paper on the bottom apart, and analyze the movement of the continents in correlation with the pulled surface.