Earth Science-Plate Tectonics

Wegener’s continental drift hypothesis stated that all the continents once joined together to form ____.

• two major supercontinents

• two major supercontinents and three smaller continents

• one major supercontinent

• three major supercontinents

The supercontinent in the continental drift hypothesis was called ____.

• Panthalassa

• Pangaea

• Mesosaurus

• Africa

What hypothesis states that the continents were once joined to form a single supercontinent?

• plate tectonics

• seafloor spreading

• continental drift

• paleomagnetism

One kind of evidence that supports Wegener’s hypothesis is that ____.

• the same magnetic directions exist on different continents

• major rivers on different continents match

• land bridges still exist that connect major continents

• fossils of the same organism have been found on different continents

Which of the following was NOT used in support of the continental drift hypothesis?

• fossil evidence

• paleomagnetism

• ancient climate

• fit of South America and Africa

According to the theory of plate tectonics, ____.

• the asthenosphere is divided into plates

• the lithosphere is divided into plates

• the asthenosphere moves over the lithosphere

• the asthenosphere is strong and rigid

Which of the following statements correctly describes the asthenosphere?

• It is a thin, cold, and rigid layer.

• It is the source of Earth’s heat.

• It permits plate motion.

• It occurs only near subduction zones.

In the plate tectonics theory, the lithosphere is divided into ____.

• 100 major plates

• 7 major plates and many smaller plates

• many small plates, but no large plates

• 50 major plates and many smaller plates

The lithospheric plates move an average of ____.

• 5 inches per year

• 50 inches per year

• 5 centimeters per year

• 50 centimeters per year

In the plate tectonic theory, a plate can be made up of ____.

• continental lithosphere only

• oceanic lithosphere only

• both continental and oceanic lithosphere

• both continental and oceanic asthenosphere