Chapter 2 - Forces of Plate Motion

Which observation is NOT evidence of the plate tectonics theory?

• heat in Earth’s mantle

• similar mountains on different continents

• Mesosaurus fossils on two far-apart continents

Answer explanation

The observation of heat in Earth's mantle is not direct evidence of plate tectonics theory, as it is related to the internal heat of the Earth rather than the movement of tectonic plates.

Tags

NGSS.MS-ESS2-3

What forms along divergent plate boundaries?

• mid-ocean ridges and rifts

• subduction zones and trenches

• folded mountains and volcanoes

Answer explanation

Along divergent plate boundaries, mid-ocean ridges and rifts form as tectonic plates move apart.

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

The main force acting along a convergent boundary is

• shear.

• tension.

• convection.

• compression.

Answer explanation

The main force acting along a convergent boundary is compression, which involves the plates moving towards each other, causing rocks to be pushed together and folded or faulted.

Tags

NGSS.HS-ESS1-5

Tension is the main force acting at which type of boundary?

• divergent

• transform

• oceanic-continental convergent

• continental-continental convergent

Answer explanation

Tension is the main force acting at divergent boundaries where tectonic plates move away from each other.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

Which statement correctly describes a force acting at a plate boundary?

• Shear is the main force acting along a transform boundary.

• Tension is the main force acting along a convergent boundary.

• Compression is the main force acting along a divergent boundary.

• Convection is the main force acting along a continental-continental boundary.

Answer explanation

Shear is the main force acting along a transform boundary, making it the correct statement.

Which formation occurs when plates move horizontally past each other?

• ocean trench

• transform fault

• mid-ocean ridge

Answer explanation

When plates move horizontally past each other, a transform fault formation occurs where the plates slide against each other. This makes the correct answer choice the transform fault.

A volcanic arc forms when

• two plates move laterally past each other.

• divergence occurs along a mid-ocean ridge.

• an oceanic plate is subducted into the mantle.

Answer explanation

A volcanic arc forms when an oceanic plate is subducted into the mantle, leading to the melting of the plate and the formation of magma that rises to the surface, creating volcanic activity.

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

Fracture zones are common

• in oceanic sediment.

• along mid-ocean ridges.

• deep within oceanic trenches.

Answer explanation

Fracture zones are commonly found along mid-ocean ridges, making this the correct choice.

Which of the following transform faults can be seen on Earth's surface?

• Mid-Atlantic Ridge

• San Andreas Fault

• Mariana Trench

Answer explanation

The San Andreas Fault is a well-known transform fault visible on Earth's surface, marking the boundary between the Pacific and North American tectonic plates. In contrast, the Mid-Atlantic Ridge is a divergent boundary, and the Mariana Trench is a subduction zone.

True or False: A mid-ocean ridge forms when tension acts on seafloor rocks.

• True

• False

Answer explanation

A mid-ocean ridge forms due to tension acting on seafloor rocks, causing them to spread apart and create new oceanic crust. Therefore, the statement is True.