Plate motion

Fossil remains of Glossopteris (an extinct plant with large leaves) have been discovered in India and Australia. When they were living, all the Glossopteris were located together on land, but now the Glossopteris fossils are separated by an ocean. What could explain how these fossils got so far apart?

• India and Australia are parts of different plates. The plates slowly moved apart as new plates from underneath got added between them over millions of years.

• India and Australia are parts of different plates. The plates slowly moved far apart as soft, rock from underneath got added to the edges of the plates over millions of years.

• India and Australia are parts of different plates. The plates floated away from each other across the ocean.

• India and Australia are parts of different plates. The plates were sometimes pushed far apart by earthquakes, and soft, solid rock from underneath got added to the edges of the plates.

India, a country that is part of Asia, was not always connected to the Asian continent. How did India come to be part of Asia?

• India and Asia are parts of different plates. The plates were sometimes pushed toward each other by earthquakes, and one plate went under the other plate into soft, solid rock.

• India and Asia are parts of different plates. The plates floated toward each other across the ocean.

• India and Asia are parts of different plates. The plates slowly moved toward each other over millions of years. When the plates hit each other, they broke into smaller pieces.

• India and Asia are parts of different plates. The plates slowly moved toward each other as one plate went under the other plate and into the mantle to melt and be recycled.

Similar rock formations have been discovered in the United States and Morocco. These rock formations were formed at the same time and are made of the same types of rocks. What could explain how these rocks got so far apart?

• The United States and Morocco are parts of different plates. The plates were sometimes pushed far apart by earthquakes, and soft, solid rock from underneath got added to the edges of the plates.

• The United States and Morocco are parts of different plates. The plates floated away from each other across the ocean.

• The United States and Morocco are parts of different plates. The plates slowly moved far apart as soft, solid rock from underneath got added to the edges of the plates over millions of years.

• The United States and Morocco are parts of different plates. The plates slowly moved apart as new plates from underneath got added between them over millions of years.

Similar rock formations have been discovered in the United States and Portugal. These rock formations were formed at the same time and are made of the same types of rocks. What could explain how these rocks got so far apart?

• The United States and Portugal are parts of different plates. The plates were sometimes pushed far apart by earthquakes, and soft, solid rock from underneath got added to the edges of the plates.

• The United States and Portugal are parts of different plates. The plates floated away from each other across the ocean.

• The United States and Portugal are parts of different plates. The plates slowly moved apart as new plates from underneath got added between them over millions of years.

• The United States and Portugal are parts of different plates. The plates slowly moved far apart as soft, solid rock from underneath got added to the edges of the plates over millions of years.

Which statement best describes Earth’s outer layer underneath the surface in the image?

• Underneath the soil, Earth’s outer layer is made of water.

• Underneath both the soil and the ocean, Earth’s outer layer is made of sand and water.

• Underneath the soil, Earth’s outer layer is made of hard, solid rock. Underneath the ocean, Earth’s outer layer is made of sand.

• Underneath both the soil and the ocean, Earth’s outer layer is made of hard, solid rock.

Dr. Choi and his team of geologists have been studying GPS data that shows that two plates moved apart. Which diagram shows what happened between the two plates as they moved away from each other?

• Diagram A: Soft, solid rock from underneath the plates rose and hardened, adding solid rock to the edges of both plates.

• Diagram B: Sand and dirt filled in the gap that was created by the plates moving apart.

• Diagram C: Ocean water filled in the gap that was created by the plates moving apart.

• Diagram D: A new plate from underneath filled in the gap that was created by the plates moving apart.

A team of geologists wants to study hard, solid rock under the surface of Earth. The team is considering drilling down in the North Atlantic Ocean (1) and in Sierra Leone (2). Where will the team find hard, solid rock?

• only under 2, because Earth’s outer layer is made of hard, solid rock under continents but not under the ocean

• under 1 and 2, because Earth’s entire outer layer is made of hard, solid rock

• neither under 1 nor 2, because there is water under both places

• neither under 1 nor 2, because there is sand and gravel under both places

Dr. Steiner and her team have been using GPS to track two plates that are moving toward each other. Which diagram shows what is happening at the place where the plates are moving toward each other?

• Diagram A: Two plates are hitting each other, and the plates are breaking into pieces, creating sand.

• Diagram B: Two plates are pushing against each other, causing the edges to bend upward.

• Diagram C: One plate is going underneath the other plate and sinking into the soft rock below.

• Diagram D: One plate is going underneath the other plate and sinking into the ocean below.

Which statement best describes Earth’s outer layer underneath the surface in the image?

• Underneath the soil, Earth’s outer layer is made of hard, solid rock. Underneath the ocean, Earth’s outer layer is made of sand.

• Underneath both the soil and the ocean, Earth’s outer layer is made of hard, solid rock.

• Underneath the soil, Earth’s outer layer is made of water.

• Underneath both the soil and the ocean, Earth’s outer layer is made of sand and water.

Dr. Mendoza and his team are studying two plates that are far apart from each other. However, these two plates used to be next to each other. Which diagram shows what happened between these plates?

• Diagram A: Sand and dirt filled in the gap that was created by the plates moving apart.

• Diagram B: Soft, solid rock from underneath the plates rose and hardened, adding solid rock to the edges of both plates.

• Diagram C: A new plate from underneath filled in the gap that was created by the plates moving apart.

• Diagram D: Ocean water filled in the gap that was created by the plates moving apart.