4.3 Drifting Continents4.3 Drifting Continents

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I. The Theory of Continental DriftI. The Theory of Continental Drift A. Alfred Wegener, German scientist

formed a hypothesis on Earth’s continents.

B. Wegener’s hypothesis was that all the continents had once been joined together in a single landmass and have since drifted apart

A. Alfred Wegener, German scientist formed a hypothesis on Earth’s continents.

B. Wegener’s hypothesis was that all the continents had once been joined together in a single landmass and have since drifted apart

C. Pangaea = all lands. D. Continental drift - the continents

slowly move over Earth’s surface E. Evidence From Landforms

Mountain ranges in South Africa lined up with a range in South America.

C. Pangaea = all lands. D. Continental drift - the continents

slowly move over Earth’s surface E. Evidence From Landforms

Mountain ranges in South Africa lined up with a range in South America.

F. Evidence from Fossils -

Fossils are any trace of an ancient organism that has been preserved in rock.

Mesosaurus and Lystrosaurus fossils have been found in Africa and South America.

F. Evidence from Fossils -

Fossils are any trace of an ancient organism that has been preserved in rock.

Mesosaurus and Lystrosaurus fossils have been found in Africa and South America.

MESOSAURUSMESOSAURUS

LYSTROSAURUS

LYSTROSAURUS

GlossopterisGlossopteris

G. Evidence from Climate

Glaciers were found in South America, Africa, India, Australia, Antarctica

G. Evidence from Climate

Glaciers were found in South America, Africa, India, Australia, Antarctica

II. Scientists Reject Wegener’s TheoryII. Scientists Reject Wegener’s Theory Wegener thought that mountains

formed when drifting continents collided, causing their edges to crumple and fold.

Mountains usually occur in narrow bands along the edges of continents, as you would expect if the collision of continents forms mountains.

Wegener thought that mountains formed when drifting continents collided, causing their edges to crumple and fold.

Mountains usually occur in narrow bands along the edges of continents, as you would expect if the collision of continents forms mountains.