Pangea and. Continental Drift

Pangea and Continental drift

Alfred concluded that all the evidence he found showed that; once there was a massive supercontinent that all the others where part of .
Pangea

Wegener’s Idea

Multiple Choice

What is pangea?

• Pangaea is a type of extinct bird species
• Pangaea is a type of flower found in South America
• Pangaea is a famous painting by Leonardo da Vinci
• Pangaea was a supercontinent that existed about 300 million years ago.

• Pangea comes from the Greek word meaning “All Lands”.

• It reached from pole to pole.

• Was centered over where Africa now lies.

What is Pangea?

Multiple Choice

In Greek what does Pangea mean?

• Entire Earth
• Complete Globe
• Whole World
• All Lans

• About 200 million years ago Pangea started to break a part.

• 18o million years- Pangea is now Gondwanaland and Laurasia.

• 65 million years - Most major continentes have move apart.

• Present - the continents reach modern positions.

Broken Lands

Multiple Choice

What did the earth look like as Pangea?

• One Large landmass, one large Ocean

• Pangea was a barren desert with no vegetation
• Pangea was a collection of separate continents
• Pangea was a small island surrounded by water

Multiple Choice

How could the earth have looked 180 million years ago?

• The earth 180 million years ago would have been covered in ice and snow
• The earth 180 million years ago would have been a lush tropical paradise
• The earth could have split into two smaller continents.

• The earth 180 million years ago would have been completely underwater

Multiple Choice

About how long ago did most of the major continents become separate?

• 65 million years ago

• 50 million years ago
• 500 million years ago
• 1 billion years ago

• In the 1950’s the sea floor was mapped, was not flat and smooth

• Mid-Ocean Ridges were found

  • Underwater mountain ranges

  • Circle the earth like stitches on a baseball.

Sea floor and Pangea

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The under water mountain range that are like the stitches on a baseball around the earth​

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Mid-Ocean Ridges

Mid-Sea Ridges

Underwater Ridges

• Ridges formed on cracks in the crust

• Molten rock (magma) rises through the cracks, and cools.

• New oceanic crust is made.

• Sea floor slowly spreads.

• These areas are called “Spreading Centers”

Sea Floor spreading

Drag and Drop

The area where new oceanic crust is made and causes the the sea floor to spread​

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Drag these tiles and drop them in the correct blank above

Spreading Centers

Subduction Zones

Trenches

• Age of the sea floor come from rocks in spreading centers.

• A special ship called Glomar Challenger dug up the rocks

  • Younger rocks are closer to the ridge, older rocks are farther and deeper away.

• Ocean crust is 160 - 180 Million yrs, Continental Crust 4 Billion yrs old.

Age of the sea floor

Dropdown

Spreading center can help us figure out the age of sea floor. The ​

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rock is found ​

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• The sea floor is still spreading, why isn’t the earth larger?

• Hugh chunks of old oceanic crust in falling into the asthenosphere.

  • Old crust is destroyed as fast as new crust is made.

• Earth stays the same size.

Ocean Trenches

• Plates rest on the asthenospheere.

  • Move by the Transfer of heat through the movement of a fluid CONVECTION.

• Convection happens when material at the bottom get really hot and les dense and rises. At the top cools, becomes more dense, and sinks - EX. Boiling pot of water

• If the rising and sinking happen a lot, the motion transfers energy - Convection Currents.

• Cause the plates to move.

Plate move?

Multiple Choice

What is convection?

• A type of dance movement
• Transfer of heat through the movement of a fluid
• A method of preserving food
• A type of rock formation

Multiple Choice

What is an example of convection?

• Boiling water in a pot
• A car engine overheating
• A person sweating
• Rising of warm air and sinking of cool air

Multiple Choice

Explain Convection current?

• Convection current is the movement of fluid due to the variation in density
• Convection current is the movement of gas due to the variation in pressure
• Convection current is the movement of solid due to the variation in temperature
• Convection current is the movement of fluid due to the variation in temperature, creating a circular motion.

Theory of plate Tectonics

• In the mid 1900’s new evidence was found that showed that Wegener’s idea were possible.

• The combined knowledge of the Lithosphere, the sea floor, the asthenosphere were used to create

  • THE THEORY OF PLATE TECTONICS.

    • The earths lithosphere is made of Hugh plates that move over the earth surface.

• Over time we learned they could not move around without affecting other plates.

• The plates can move apart, push together or scrape past each other .

• The movements cause great changes on the crust.

plates movements

Multiple Select

How do Tectonic plates move?

(Choose all that apply.)

• Move apart

• Push Togther

• Scrap past each other

• Do little dance