A Planet on the MoveA Planet on the Move

Geological Processes of EarthGeological Processes of EarthBy Jeff PathfinderBy Jeff Pathfinder

Heritage Intermediate SchoolHeritage Intermediate School

6th Grade6th Grade

ObjectivesObjectives

• Describe how the continents have moved over the past 250 billion years.

• Provide support for these theories.

• Explain the effects of this movement on the Earth’s surface.

IntroductionIntroduction• Study the shapes of the continents closely

while looking at a globe or map of the world. Do you notice anything about the continents on opposite sides of the Atlantic Ocean?

Continental Drift Continental Drift

http://dgl.mircrosoft.com.html

• Alfred Wegener did! A German geologist, Wegener proposed the theory of continental drift. He calculated that 200 million years ago the continents were originally joined together, forming a large super continent. He named this super continent Pangaea, meaning "All-earth".

Evidence... Evidence...

Same type of rocks on each continent.

Same type fossils on each continent.

Seafloor SpreadingSeafloor Spreading• In the 1950’s scientists began to look at the

ocean floor for evidence of this movement.• They noticed deep sea trenches and rifts.• Age Evidence and Magnetic Clues provided

further evidence that Wegner had been correct!

Plate TectonicsPlate Tectonics• In the 1960’s scientists theorized Plate

Tectonics.• Earth is made of 10 plates that “slide” around

on the plastic-like layer of the earth below the crust called the asthenosphere.

Plate MovementPlate Movement

• Convergent

• Divergent• Transformanother…earthquakes

ConvergentConvergentPlates collide…volcanoes, mountains

http://pubs.usgs.gov/publications/text/understanding.html

DivergentDivergent

Copywrite 1999 John Wiley and Sons, Inc.

Plates move apart…ridges, rift valleys

TransformTransform

Plates slide past one another…earthquakes!

Copywrite 1999 John Wiley and Sons, Inc.

http://www.branches.co.uk/earth/tectonic.htm

Do You Remember?Do You Remember?

• 1. Define Pangaea.• 2. Describe Wagner’s theory.

• 3. What evidence is there of Seafloor Spreading?

• 4. Describe Plate Tectonics.• 5. Name and describe the 3 Plate

Boundaries.

Works CitedWorks CitedEarth Science, Glencoe/ McGraw Hill. Columbus, Ohio, 2001 Research and images , http://www.enchantedlearning.comhttp://dgl.mircrosoft.com.htmlhttp://pubs.usgs.gov/publications/text/understanding.html

Copywrite 1999 John Wiley and Sons, Inc.