Plate Tectonics and Earth's Interior

Who came up with the idea that all the continents were once joined together?

• Albert Einstein
• Alfred Wegener
• Charles Darwin

What is Pangaea?

• an ice sheet which covered several continents
• the fossil of a fern found on different continents
• a mountain belt linking two continents
• a supercontinent that contained all the continents

Lystrosaurus was a slow-moving, plant-eating reptile that lived over 250 million years ago. Fossils of Lystrosaurus have been found in the brown areas shown below. How is this explained by the existence of Pangaea?

• Lystrosaurus swam across the oceans from one continent to another.
• Lystrosaurus drifted on rafts of vegetation from one continent to another.
• Land bridges once crossed oceans to connect Africa, Antarctica, and India.
• Africa, Antarctica, and India used to be joined together into a single landmass.

What is the theory of continental drift?

• The continents move slowly over Earth's surface.
• The continents moved millions of years ago, but now they are fixed in one place.
• The continents were fixed in one place, but recently they have begun to move.

What clue supported the continental drift hypothesis?

• Fossils of animals have been found on continents separated by oceans
• Similar coal beds and rock structures have been found on different continents
• A puzzle-like fit of all the continents
• All answers are correct

What is the source of most of the information scientists have about Earth's interior?

• deep wells drilled in the ground
• satellite imaging
• analysis of earthquake waves
• studies of landforms

Which layer of the Earth is made up of tectonic plates?

• the core
• the asthenosphere
• the lithosphere
• the mantle

What defines the mechanical layers of the Earth?

• how the layers move and behave due to their strength and the pressure that they are under
• how the layers are separated due to their different densities

Which mechanical layer of the Earth is made up of solid rock that is so hot it has the quality of *plastic*, or is soft enough to flow?

• lithosphere
• asthenosphere
• lower mantle
• outer core

As scientists explore deeper and deeper into Earth's crust, what have they noticed about temperature and pressure?

• both temperature and pressure decrease
• both temperature and pressure increase
• pressure increases while temperature decreases
• temperature increases while pressure decreases