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Tectonic Plates

Ernesto R. Maldonado, María Daniela Orozco Gabriela L. Rivera

 

• Continental Drift

Wegener’s hypothesis pointed out that some time in our world the continents were united in one single mass. That single mass was known as a super continent which slowly seperated into five continents as the centuries went by. Even though Wegener couldn’t clearly explain the forces that moved or pulled the continents, evidence of climatic changes supported his hypothesis.

 

• Pangea

 

            Some botanic and animal species are found in various continents. It’s unthinkable that these species were able to go to other continents through the ocean, but they could have easily scattered when all the continents were united.

 

Fact: Archaeologists found rocks of the same type, age, and formations in West Africa and East South America.

 

• Expansion of the ocean floor

 

            The expansion of the ocean floor adds more cortex to the ocean floor, and at the same time there are more ancient belts of rocks separating from both sides of the range. This event dragged the continents.

 

Evidence of the expantion of the ocean floor:

 

• Eruption of melted material: cushioned lava

 

• Magnetic stripes on rocks of the ocean floor: the same pattern on both sides of the ocean range.

 

• Age of rocks: younger rocks are in the center of the range.

 

 

• Tectonic Plates

 

            The Earth is divided into several plates– A seccion of the litosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust.

 

The Tectonic Plates Theory establishes that the Earth’s plates move at a slow and constant speed, and it is impulsed by the currents of convection of the Earth’s mantle.