Ch 7 Lesson 2 Development of a Theory

Front

What is seafloor spreading?

Back

Seafloor spreading is the process by which new oceanic crust is formed at mid-ocean ridges and older crust is pushed away from the ridge.

Front

What evidence supports seafloor spreading?

Back

Evidence includes ocean material, magnetic stripes, and drilling samples.

Front

Which evidence is NOT related to seafloor spreading?

Back

Evidence from climate.

Front

How do scientists determine the age of the seafloor?

Back

They take drill ships to various ocean locations to collect and date rock samples.

Front

Where is the youngest seafloor found in the Atlantic Ocean?

Back

Towards the middle of the ocean.

Front

What role do mid-ocean ridges play in seafloor spreading?

Back

Molten material rises from the mantle and erupts along mid-ocean ridges.

Front

What was a major reason the Continental Drift theory was initially rejected?

Back

Scientists did not know the force responsible for moving the continents.

Front

What are magnetic stripes and how do they relate to seafloor spreading?

Back

Magnetic stripes are patterns of magnetic orientation in rocks that provide evidence of seafloor spreading.

Front

What is the significance of drilling samples in studying the seafloor?

Back

Drilling samples allow scientists to date the age of the seafloor and understand its composition.

Front

What is the mantle in relation to seafloor spreading?

Back

The mantle is the layer of the Earth from which molten material rises to create new oceanic crust.