U4 M2 L2 - Development of a Theory Lamb

The THEORY of (a)   explains how new crust is created (and explains Continental Drift)

A vast, underwater mountain chain is called a(n) ______.

• ocean ridge
• deep-sea trench
• oceanic crust
• ocean floor sediment

Which of the following best explains the age of oceanic crust and ocean-floor features?

• seafloor spreading
• continental drift
• subduction
• crystallization

The youngest rocks on the ocean floor are located _____.

• near continents
• at mid-ocean ridges
• far from mid-ocean ridges
• near Asia

The molten material deep inside Earth from which igneous rocks form is called _________.

• magma
• lava
• neither a nor b
• both a and b

New ocean crust is continually formed at _____.

• trenches
• mid-ocean ridges
• subduction zones
• ocean basins

What new technology was used to map the seafloor beginning in the 1940s and 1950s?

• LASER beams
• Metric system
• SONAR
• GPS