By VedaRuth, Ava, and Geir
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All About The Authors
VedaRuth VedaRuth is 11 years old . She lives with her father, her mother and her brother. She has two dogs and four cats. She loves to dance and is on a swim team. In the summer, she loves to go swimming at Lake Wyola and hangout with her friends.
Ava Ava is 12 years old and lives with her sister, her mother, and her grandparents. She has two dogs, two cats, a parrot, a tortoise, and three chickens. She loves to dance and draw. Ava enjoys spending her summer days swimming in her pool and going to various places like Wells Beach, Maine and Prudence Island, Rhode Island.
Geir Geir is 12 years old and lives with his two sisters, his mother, and his father. He has no pets, but wants a dog. He loves playing ultimate frisbee, skiing, snowboarding and riding his long board. He also enjoys going to North Carolina with his family and going on other vacations.
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4th grade Teacher: mr.Shaw
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“Ok Papa, I’ll be right out with my homework,” said Virginia. “Ok, I’ll wait in the car,” said Papa. “Hey Virginia,” said Mr. Shaw, Virginia’s teacher. “While you were at the dentist, we talked about the science fair that is coming up. Everybody already chose their topics. The only one left is Pangaea so you have to do it.” “Um… ok,” said Virginia, with a hint of worry in her voice. As soon as she was done talking with Mr. Shaw, she headed out the door to greet her dad in the car.
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When Virginia got home, she started on her homework. As she pulled out the science fair page she thought, “What was Pangaea? Papa’s a scientist. He has to know what was Pangaea.” “Hey Papa, I have a question.” Virginia said. “What is it?” Papa asked.
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“Since I wasn't at school when they chose the science fair options, I was assigned Pangaea because that was the only one left. And I don't know anything about it!” Virginia said frantically. “Don't worry sweetie, I know a lot about Pangaea!” Papa answered.
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Gaea
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“Once upon a time, there was a beautiful princess named Gaea (Gee-uh). Just kidding. Once upon a time, there was a supercontinent* named Gaea and now she has come back to help me make learning about Pangaea more fun,” Papa said. ”Meet Gaea, Virginia.” “Hi Gaea, it’s nice to meet you,” Virginia said. “Hi Virginia. I’m looking forward to helping you learn about Pangaea,” Gaea said. “200 million years ago the earth looked a lot different. Back then before people existed, the continents were touching!” Papa said. “I know that sounds crazy, but it's true!” Gaea said. “And before that there were two other major land masses: Rodinia and Pannotia. Rodinia happened 800 million years before Pangea and 1 billion years before present day. Pannotia happened 400 million years before Pangea and 600 million years before present day.” Papa said.
* Supercontinent: A big land mass that is made up of the majority of the land on earth.
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Rodinia
Pangaea
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Pannotia
“But how did it go from Rodinia, to Pannotia, to Pangaea?” asked Virginia. “Well the mantle* is more than 1,800 degrees Fahrenheit. And because it is so hot, the rocks inside the mantle melt, and that liquid starts flowing toward the crust because warm molecules rise. Pressure from the rocks in the crust stops them from melting in the heat,” Papa answered. * Mantle: The melted rock that’s in-between the crust and the core.
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Crust
Mantle
Core
Convection Current The arrows in the center of the mantle represent the direction the melted rock flows, which causes tectonic plates to move.
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“As the rocks get closer to the surface, they start to cool down. Because cold molecules sink, they start to flow sideways, then they go back towards the core. This creates a giant convection current which moves the top crust, causing the plates to move. A simpler way to say it is that the sideways movement of rocks under the crust is what causes tectonic plates to move. When two currents move together, the plates on top move together too. And when two currents move apart, so do the plates on top. That is how it went from Rodinia to Pannotia to Pangaea,” said Papa. “Now that you know how tectonic plates were formed, there is one more thing you have to know. Tectonic plates are not all the same size. Some are big and some are small. They also don't all move in the same direction. Some could be moving toward each other and some could be moving away. But the important information is that tectonic plates are what allow our continents to move. And our continents are still moving today,” said Papa. “Well, of course, we know that tectonic plates move. But how were they formed?” Virginia asked.
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“Well, the earth constantly generates heat from our mantle and releases it through the cracks between tectonic plates. This is how our earth doesn’t overheat. But billions of years ago, when Earth formed, there weren't tectonic plates. The reason there weren't tectonic plates was Earth was first made of melted rock. So there wasn't even crust. Because Earth had no way to release her heat, she just kept getting hotter and hotter,” said Papa. “You think you could speed up the story, I'm burning up over here!” said Earth. “Right, sorry Earth. Anyway, she just kept getting hotter and hotter, until suddenly she felt herself cooling down. Crackle, crackle, she saw that she was breaking apart,” said Papa. “What's happening to me?” said Earth. “Earth quickly realized that the cracks, which are what created tectonic plates, allowed a place for all her heat to escape. She would never be burning hot again! Now Earth was a smart planet. She knew that if there was a good side to the cracks, there had to be a bad side as well. It wasn't long before she figured out the bad side. She realized that parts of her body were floating away,” said Papa. “Uh, oh," said Virginia, “what's going to happen to Earth?” “Well, it turns out that the cracks weren't really a bad thing. They are what created Pangaea and all the supercontinents and continents we know today,” explained Papa. “Since I'm not all together anymore, I am going to need a new name. How about Pangaea or Gaea for short?” said Gaea. “Huh, interesting. You have already told me about what super continents were before Pangaea, but what happened after Pangaea?” asked Virginia.
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Pangaea
“There used to be many different theories about what came after Pangaea. But the one that scientists agree on now is this: first came Pangaea, then Laurasia and Gondwana, and then our continents broke apart into nearly the location they are in today,” said Papa. “Wait, what?” said Virginia. “Right, I should probably break it down,” said Papa. “First came Pangaea. Pangaea formed 240 million years ago and didn't start breaking part until 40 million years later.”
“Then Pangaea broke apart into two supercontinents called Laurasia and Gondwana. Laurasia was made up of the continents we call Europe, Asia, and North America. Gondwana was made up of Africa, Australia, South America, and Antarctica. They existed 150 million years ago.”
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Laurasia
Gondwana
Asia North America
Europe Africa
South America Australia Antarctica
“And last, but not least, came our continents arranged close to the same way as they are now.�
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“Cool, but what evidence do we have that Pangaea ever existed?� Virginia asked.
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Africa India
South America
Antarctica
A
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u
s
al tr
ia
“The first piece of evidence, and one of the most important pieces of evidence, is that the continents look like they could fit together,” Papa said. “Like a puzzle?” Virginia asked. “Yeah,” said Gaea happily. “But how else did they know?” Virginia asked.
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The fossil remains of the plant Glossopteris The fossil remains of the reptile Lystrosaurus The fossil remains of the reptile Cynognathus The fossil remains of the reptile Mesosaurus
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“One of the first and most important pieces of evidence was fossil evidence. Scientists found similar fossils in southern South America and western Africa,” Papa said. “Wait, I don't understand, I have a question. What do fossils even tell us about Pangea?” Virginia asked. “Well, the scientists realized that if I existed 200 million years ago, the small animals just lived in the same place because I was one big landmass,” Gaea said. “What kind of animal fossils did they find?” Virginia asked. Papa started to give examples. “One of the fossils they found was a mesosaurus fossil, an aquatic reptile that lived 229 million to 271 million years ago. The reptile fossils were found in southern South America and Africa. That might be a little confusing, here look at this map of fossil remains.” “A second example is a land animal called a Lystrosaurus. This animal lived 251 to 199 million years ago. It lived in India, Antarctica, and southeastern Africa,” Papa finished.
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The white is the glacial till deposits/glaciers
“Another piece of evidence is the location of glacial till deposits,”Papa said “What are those?” asked Virginia. “A glacial till deposit is when a glacier releases the rocks and sediment it has been carrying as it moves. When it melts, it leaves its till behind.” “But what do glacial till deposits tell us about Pangaea?” Virginia asked. “Well, scientists found similar glacial till deposits on many different continents, which made it look like the glaciers had moved in a zigzag formation.”
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Glacial till deposits/glaciers
“But how could a giant piece of ice like a glacier move in a zigzag?” Gaea asked in confusion. “Scientist’s only answer is that when the continents are fit together, it just looks like the glaciers had receded in a circle.” “Oh, I get it,” Virginia replied.
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“Another piece of supporting evidence for the existence of Pangea is climate belts. A climate belt is a strip of the world with a certain climate. There are all sorts of climate belts, like tropical, desert and others.�
Pink and Red = Temperate Zone
Yellow= Tropical 25
Orange and Blue = Subtropical
Virginia started to understand, “Oh, so you know they were connected because they have similar climates.” “Exactly,” said Papa.
“Well, for example, when India and the middle of Africa were side-by-side, they were in the same climate belt. They still are, meaning they have the same climate. But now India and Africa are very far away,” Papa said. Virginia started to understand, “Oh, so you know they were connected because they have similar climates.” “Exactly,” said Papa.
“Okay, I get it now Papa.” Virginia said. “Come on Gaea, let’s go make my presentation,” Virginia said under her breath. “I have tons of ideas,” Gaea replied.
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