CONTINENTAL DRIFT es/outreach/sumatra/pangaea.mov

Alfred L. Wegener  Geologist Alfred Wegener noticed similar rocks & fossil remains were found on continents which seemed to fit together  He called this “super” continent called Pangaea  In 1912 Wegener published the first version & died defending his theory  Geologist Alfred Wegener noticed similar rocks & fossil remains were found on continents which seemed to fit together  He called this “super” continent called Pangaea  In 1912 Wegener published the first version & died defending his theory

PANGAEA the large landmass that included all of Earth’s present day continents

Support for Continental Drift 1. SHAPE OF THE CONTINENTS Continents fit together like puzzle pieces 1. SHAPE OF THE CONTINENTS Continents fit together like puzzle pieces

Support for Continental Drift  Wegener was not the only one to notice the fit of the continents.  1858: Antonio Pelligrini depicted Africa and South America connected.  He was one of the first scientists to publish maps depicting the apparent fit of the continents.  Wegener was not the only one to notice the fit of the continents.  1858: Antonio Pelligrini depicted Africa and South America connected.  He was one of the first scientists to publish maps depicting the apparent fit of the continents. 1. SHAPE OF THE CONTINENTS

Mesosaurus and Lystrosaurus were incapable of swimming across a large ocean. 2. EVIDENCE FROM FOSSILS SAME FOSSILS: DIFFERENT CONTINENTS Support for Continental Drift

Fossils of the gymnosperm Glossopteris  Found in all of the southern continents provide strong evidence that the continents were once a supercontinent  ( seeds could not travel the great distances and were too fragile to survive by a trip across the ocean)  Found in all of the southern continents provide strong evidence that the continents were once a supercontinent  ( seeds could not travel the great distances and were too fragile to survive by a trip across the ocean)

3. EVIDENCE FROM LANDFORMS Mountain ranges 3. EVIDENCE FROM LANDFORMS Mountain ranges Support for Continental Drift  SAME ROCK: DIFFERENT RANGE Existing mountain ranges separated by vast oceans contain rocks of identical mineral content.  A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles.  SAME ROCK: DIFFERENT RANGE Existing mountain ranges separated by vast oceans contain rocks of identical mineral content.  A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles.

3. LOCATION OF COAL DEPOSITS Coal deposits have been found in temperate and polar regions; however, coal is formed in tropical regions. Support for Continental Drift

GLACIAL SCARS- SAME SCARS: DIFFERENT CONTINENTS Support for Continental Drift 4. Evidence of Climate

4. Evidence of Climate (cnt’d)  Scientists found evidence of TROPICAL plants on the island of Spitsbergen (which is now in the Polar Arctic region. Spitsbergen must have been in a tropical climate at one time.

CONTINENTAL DRIFT IN DOUBT Why didn’t people believe in continental drift?  People couldn’t image how the earth could be millions of years old  People couldn’t image a force great enough to move the continents BUT by the 1960’s evidence would prove continental drift is TRUE and…. The story continues (as does all good science!) Why didn’t people believe in continental drift?  People couldn’t image how the earth could be millions of years old  People couldn’t image a force great enough to move the continents BUT by the 1960’s evidence would prove continental drift is TRUE and…. The story continues (as does all good science!)