Continental Drift and Evidence from Seafloor. Practice!

Continental crust is composed of ________ rocks.

• granitic

• basaltic

Oceanic crust is composed of ________ rocks.

• granitic

• basaltic

Seafloor spreading occurs because __________.

• new material is being added to the asthenosphere

• earthquakes break apart the ocean floor

• sediments accumulate at the area of spreading

• molten material rises towards the surface

The crust under the continents is thinner than the crust under the ocean.

• true

• false

Continental plates are more dense than the oceanic plates.

• true

• false

Earthquakes and volcanoes are concentrated near plate boundaries.

• true

• false

Tectonic plates consist of __________.

• continental crust

• oceanic crust

• both oceanic and continental crust

• mesospheric rocks

Tags

NGSS.MS-ESS2-1

NGSS.MS-ESS2-3

What happens when rock is heated?

• rock breaks

• rock rises

• rock sinks

• rock becomes denser

What did Wegener call the single, large landmass where all the continents were joined togehter?

• Eurasia

• Gondwana

• Pangaea

• Laurasia

What discovery led scientists to accept Wegener's continental drift hypothesis?

• seismographs

• Pangaea

• sea-floor spreading

• magma