SEAFLOOR SPREADING FORMATIVE ASSESSMENT

1. According to the Seafloor spreading theory, the youngest rocks on the ocean floor are located in ______.

• near Asia

• near the continents

• at mid-ocean ridges

• far from mid-ocean ridges

2. Why were magnetic patterns or stripes are found on the rocks of the ocean floor?

• They showed that all the rocks are magnetic

• They showed that no rocks were magnetic

• They did not show alternating bands of normal and reversed polarity

• They showed alternating bands of normal and reversed polarity

3. Which of the following does NOT support the theory of seafloor spreading?

• the youngest rocks are found far from the mid ocean ridge and the oldest are found at the ridge

• pillow shape rocks show that magma sees into the ocean at divergent plate boundary

• oldest rocks are farthest away from the mid-ocean ridge and the youngest rocks are at the ridge

• magnetic reversals recorded in the ocean crust match up together on each side of the mid-ocean ridge.

4. Which of the following theory continually adds new crust to the ocean floor along both sides of the mid-ocean ridge?

• Plate Tectonic

• Seafloor Spreading

• Continental Drift

• Magnetic Reversal

5. Which of the following technological advances change how scientists viewed the ocean floor?

• sonar

• magnetometer

• spectrograph

• underwater telescope

6. What sediment evidence led to the discovery of seafloor spreading?

• layers of sediments on the ocean floor are much heavier than layers of sediments on continents

• layers of sediments on the ocean floor are much lighter than layers of sediments on continents

• layers of sediments on the ocean floor are much thinner than layers of sediments on continents

• layers of sediments on the ocean floor are much thicker than layers of sediments on continents

7. He is credited for his theory which explains that oceanic crust is formed at ocean ridges, slowly moves away from the ocean ridges and is destroyed at deep-sea trenches.

• Alfred Wegener

• Albert Einstein

• Harry Potter

• Harry Hess

8. Seafloor Spreading Theory states that the hot, less dense material below the earth’s crust rises towards the mid ocean ridge. Overtime the new oceanic crust pushed the old oceanic crust far from the ridge and subducted.

• First statement is True, Second statement is False

• First statement is False, Second statement is True

• Both statement are True

• Both statement are False

9. How did scientists discover that rocks farther away from the mid-ocean ridge were older than those near it?

• by observing eruptions of molten material on the seafloor

• by determining the age of rock samples obtained by drilling on the seafloor

• by measuring how fast seafloor spreading occurs

• by mapping rocks on the seafloor using sonar

10. Seafloor spreading happens because of the ______________________

• hot and more dense material below the Earth’s crust rises up

• cold and more dense material below the Earth’s crust rises up

• hot and less dense material below the Earth’s crust rises up

• cold and less dense material below the Earth’s crust rises up