Tectonic Plate Movement and Formations

Rift valleys can form when fractures in Earth's crust widen. The valley walls slowly move at a rate of only a few millimeters a year. Which of these best describes the type of tectonic activity that forms rift valleys?

• Rift valleys form where a continental plate moves under an oceanic plate.

• Rift valleys form where a plate slides horizontally past another plate.

• Rift valleys form where two plates move away from each other.

• Rift valleys form where an oceanic plate moves under another oceanic plate.

The map shows some of Earth's plate tectonic boundaries.

Based on the map, volcanic activity would most likely be found at -

• Location W

• Location X

• Location Y

• Location Z

The San Andreas fault is a transform fault. The map below shows a student's approximation of where the fault line crosses through the United States. Students were asked to make maps predicting which way land would most likely move over thousands of years.

Which map best predicts the likely movement of land along the fault line over thousands of years?

• 
• 
• 
• 

A mid-ocean ridge separates the Pacific plate and the Nazca plate off the western coast of South America.

Which statement best describes the relative motions of the Pacific and Nazca plates?

• The Pacific and Nazca plates are both moving to the east.

• The Pacific and Nazca plates are both moving to the west.

• The Pacific plate is moving to the west, and the Nazca plate is moving to the east.

• The Pacific plate is moving to the east, and the Nazca plate is moving to the west.

The image shows a plate boundary. Arrows have been added to indicate the movement of the plates.

What plate boundary feature is also shown?

• A ridge formed by an inactive convergent boundary

• A valley forming at an active transform boundary

• A fault forming at an active transform boundary

• A volcano formed by an active transform boundary

The map below shows the locations of four active volcanoes in the Caribbean Sea.

What do these volcanoes indicate about plate tectonics in the region?

• The volcanoes form an island arc, indicating a converging plate boundary.

• The volcanoes form a line, indicating a diverging plate boundary.

• Two plates are moving past each other, causing faulting and magma formation.

• Two plates are moving apart, creating new seafloor.

The diagram below shows a model of the movement of two tectonic plates. When the plates collide, one plate often moves below the other plate.

The rising magma that can result from this type of plate movement may produce -

• fossil layers

• volcanic islands

• deep-sea sediment

• seafloor spreading

The Himalayan mountains are shown on the map.

Which student correctly identified the geologic process that formed the Himalayan mountains?

• Student 1

• Student 2

• Student 3

• Student 4

The model below shows two continental plates.

The folded mountains in this model form at which type of plate boundary?

• Transform boundary

• Divergent boundary

• Subduction boundary

• Convergent boundary

The thick black lines on the map show the locations of mid-ocean ridges.

Which geologic feature is most likely to form at a mid-ocean ridge?

• Peninsula

• Volcano

• Delta

• Plateau