Plate Motion

Front

Why is Earth tectonically active?

Back

Earth’s solid surface layer sits on a layer of semimolten rock that slowly flows.

Front

What would most likely slow Earth’s tectonic activity?

Back

Earth’s mantle becomes cooler.

Front

Which analogy BEST illustrates how Earth’s plates move?

Back

A moving sidewalk transports travelers from one gate to another at an airport.

Front

Why have fossils of the same land-dwelling species been found in both South America and Africa?

Back

These organisms once lived on one large landmass that later split into two continents.

Front

Why have extinct broad-leaved plant fossils been found in Antarctica?

Back

Antarctica was once joined with other continents farther from the South Pole.

Front

Which discovery confirmed that the continents move on plates?

Back

spreading of the sea floor

Front

Why are remains of a small reptile from millions of years ago found only in Brazil and South Africa?

Back

plate tectonics

Front

The theory of plate tectonics is based on

Back

evidence of sea floor spreading.

Front

The Appalachian mountain range in North America is similar in age and rock composition to mountain ranges in Britain and Norway. Similarly, a mountain range that runs east to west in South Africa matches a mountain range in Argentina. Which theory does this evidence support?

Back

Continents that are now separated were once joined together.

Front

Presence of Glossopteris fossils in South America, Africa, Asia, and Antarctica. Seeds too small for wind dispersal. What does this suggest?

Back

The landmasses were joined together in prehistoric times.