Chapter 6 Plate Tectonics

3 Sections

A Plan of Attack to Learn these materials:

            Learn the names of the three sections

            Be able to understand and develop a strategy to complete each objective for each section ( 7 total for the 3 sections)

            Make index cards and /or foldables of  all vocab words

           Outline all the sections of the txt           

            Be able to answer the reading check questions

            Study all pictures and captions from the txt – be able to explain them

Go to CD and read The Reading Essentials on this material to check your understanding

            Check your knowledge and be able to explain the Summaries at the end of each section (make sure you are using the vocabulary and all other words below a (i.e. names, places,)

            Make sure you do the questions at end of chapter and get at least 90% correct (p172, 173, 174,175)

            Make sure to use and are comfortable with any graphic organizer  from txt p171, 173,, science take home notebook, reading essentials, etc),

Make sure you can answer the do nows and hw questions

            Use cd to find additional resources on chapter, answer and do those questions

Use glencoe online quizzes, for each section and chapter

            Lastly be sure to spend some time on:

Review of old material that you may have been weak in such:

 as density, longitude and latitude, rocks and minerals, fossils, weathering and erosion

Maybe even check some 6th grade material if you know it relates,

 

The Material

          

           

1       Continental Drift

Objectives: be able to describe the hypothesis of continental drift

                    Identify evidence supporting continental drift          

2       Seafloor Spreading

Objectives: explain sea floor spreading

                    Recognize how age and magnetic clues support sea floor spreading

3       Theory of Plate Tectonics

Objectives:  compare and contrast different kinds of plate boundaries

                     Explain how heat inside earth causes plate tectonics

                     Recognize features caused by plate tectonics

                    

Vocabulary:                                                               Names & places to know:

Continental drift –    p150                                           Ortelius                                                                                              

Pangea -             -     p150                                           Wegener

Seafloor spreading  p155                                                        Mesosaurus

Plate tectonics -       p158                                                        Glossopteris   

Lithosphere -           p158                                                                    Spitzbergen,

Asthenosphere -      p 158                                                                   Appalachian Mountains, Greenland, Western Europe

Convection current – p163

Hess

Review Vocabulary:

Seafloor  

Converge/Diverge

Transform

 

Additional Words:

 

Hypothesis

High density

Low density

Magma

Mid-ocean ridge

Contract/Expand

Earth’s magnetic pole (North & South)

Magnetic pole reversal

Magnetic time scale

Iron bearing minerals – magnetite, hematite

Magnetometer

Polarity

 

Section 1 Outline
I. Evidence for Continental Drift

Looking at a map of Earth’s surface it looks like the edges of some continents can fir together

                    Particularly South America and the African Coast Line

 

Pangea

Wegener suggested the “fit” was because the continents were originally joined together and created

          the theory of continental drift –that the continents moved slowly apart to their current places on the globe

          200 million years ago all continents were one landmass called

          Pangea – the first land mass on earth – means “all land”

 

A Controversial Idea

His idea was that the continents moved because of the spin of the earth

His hypothesis lacked evidence to give it support

As technology improved – evidence was found to give support to his theory of continental drift

 

1. Fossil Clues

            Mesasourus fossil found in South America & Africa

                        Since it lived in only fresh water or land (not salt water) it could not swim across salt water areas to other lands

            Wegener hypothesized it lived on one land body when they were joined

             Many of Pangea’s plant or animal fossil remains have been found in more then one continent

These various fossils have been found in separate places which are far from each other now but were all attached as Pangea

 
                        Glossopteris (plant) in Africa, Australia, India, South America, and Antarctica

                        Labrinthodont (animal) found in south Africa and Australia

                        Kannemeyerid (animal) found in Nortth America and Northern China

 

2. A Widespread Plant

          Glossopteris a widespread plant also supports his hypothesis

 

3. Climate Clues

          It is unusual that a fossil or a warm weather climate was found in the now cold Artic Region on the Island Spitzbergen

         Also glacial evidence was found in two opposite climatic regions (tropical and temperate )

                    South America, Africa, India & Australia  (glacial deposits and glacial scouring (scraping)

          The drifting continents explains why there would be glacial evidence where no glaciers exist today

                    These continental areas were connected and ice covered

 

4. Rock Clues

          Proof that the continents were once connected is noted because

A.   rocks structures present in one continent are found in different continents

a.     Appalachian mountains of the Eastern US are also seen in Greenland and Western Europe

b.    Rocks found in Eastern south American are also in Western Africa

 

II. How Could Continents Drift?

         Wegner had the right idea but couldn’t explain Why or How.

                        His idea was that lower density continental material pushed through higher density ocean floor material

                                    Because of the earth’s spin

            All his idea were rejected until many years later,

technology came which helped to bring new clues and new ideas

Sea Floor Spreading