Transcript Warm- up Question Summarize: What you know about Continental

Seafloor Spreading model
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On the thin strips, color the areas marked with an N
purple and the areas marked with an S orange.
On the base, color the area with the slit purple and the
area directly to the right and left of the slit area orange.
Alternate these colors as you go away from the center.
Cut along the dotted lines, including the slit in the
center of the base.
Place the “Tape in” side of the strips through the slit so
that the arrows point out.
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Seafloor Questions
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Answer the following questions while you wait for tape.
Define the following terms: (68-71)
Mid-ocean Ridge:
Topography:
Seafloor Spreading:
Lithosphere:
Asthenosphere:
Paleomagnetism:
What do the N and S represent? Explain why the strips of paper
alternate N and S.
Give two reasons why some of the bands are narrower than others.
Wider?
Explain how Paleomagnetism provides evidence for plate tectonics.
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Seafloor questions
1. As the magma comes up from the center, what happens to the
Oceanic Lithosphere? (The plates are pushed away from the
ridge.)
2. What type of formation is formed at the mid-ocean ridge? (Ridges
and valleys are formed.)
3. Where is the youngest rock located on the ocean floor? (The
youngest rock will be located closed to the mid-ocean ridge. The
rock gets progressively older as you move farther from the ridge
crest.)
4. Where does the magma come from? (Deep within the earth’s
crust where temperatures are hot enough to melt the rock.)
5. What so the stripes in the magma represent? (They represent the
magnetic reversals. A polarity reversal means that the magnetic
North flips to where we know the South Pole is.)
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4. Where does the magma come from?
(Deep within the earth’s crust where
 temperatures are hot enough to melt the
rock.)
 5. What so the stripes in the magma
represent? (They represent the magnetic
 reversals. A polarity reversal means that
the magnetic North flips to where we
 know the South Pole is.)
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Essential Question
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I will be able to write an explanation on
Wegener’s hypothesis of continental drift.
 Warm up
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What is continental drift
 Exit Task
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How does seafloor spreading prove
continental drift
 Homework
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Vocabulary page 78 due Friday October
24th
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Chapter 4 Vocabulary – define and
give one fact
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Continental drift
Pangaea
Panthalassa
Mid-Atlantic ridge
Mid-ocean ridges
Seafloor spreading
Plate tectonics
Oceanic crust
Continental crust
Lithosphere
Divergent boundary
Rift valley
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Asthenosphere
Convergent boundary
Subduction zone
Ocean Trench
Island arc
Transformation boundary
Convection
Convection current
Theory of Micro plate
terranes
terranes
Chapter 4 Standards
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Plate tectonics operating over geologic
time has changed the patterns of land,
sea, and mountains on Earth's surface.
As the basis for understanding this
concept:
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Students know features of the ocean floor
(magnetic patterns, age, and sea-floor
topography) provide evidence of plate
tectonics.
Students know the principal structures that
form at the three different kinds of plate
boundaries.
4.1 notes objectives
Explain Wegener’s hypothesis of
continental drift
 List evidence for Wegener’s hypothesis
of continental drift
 Describe seafloor spreading
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Explain Wegener’s hypothesis of
Continental Drift
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Explain Wegener’s hypothesis of
Continental Drift
Continental Drift – Hypothesis by Alfred
Wegener in 1912 that states continents
had moved
 Introduced the concept of Pangaea
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Pangaea - Which means all land
 Panthalassa – Which means all sea
 Provided the first evidence of continental
drift
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List evidence for Wegener’s
hypothesis of Continental Drift
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Evidence
Fit of the
continents
 Match of
mountain
belts, rock
types
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List evidence for Wegener’s
hypothesis of Continental Drift
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Distribution of fossils
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Paleoclimates
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glaciations
tropical swamps
Describe Seafloor spreading
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sea-floor spreading
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Describe Seafloor spreading
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The Renewal of the Ocean Floor
Harry Hess – Suggested that the valleys
were a break in the crust, that allowed
magma to well up and form new crust
 Proof came in the mid 1960’s from another
group mapping world wide magnetic fields
on land and sea
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Describe Seafloor spreading
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sea-floor spreading
 provides the mechanism
for continental drift.
 Mid ocean ridges are
80,000 KM long.
 Continental rock is 4
billion years old.
 Ocean Rock is 175
Million
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Describe Seafloor spreading
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paleomagnetism of the Ocean floor
fossil magnetism
 symmetrical pattern of magnetic polarity
(stripes)
 Discovered by two different groups of
scientist in 1965
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Describe Seafloor spreading
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4.2 notes objectives
Summarize the theory of Plate Tectonics
 Compare the characteristic geologic
activities that occur along the three types
of plate boundaries
 Explain the possible role of convection
currents
 Summarize the theory of Micro-plate
terranes
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Summarize the theory of Plate
Tectonics
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The Theory of Plate
Tectonics is a theory that
includes both continental
drift and seafloor
spreading to explain
continental movements.
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Earth’s crust made of two
types; oceanic and
continental
Two Levels the Lithosphere
(top) and the
Asthenosphere (bottom)
Summarize the theory of Plate Tectonics
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Lithospheric Plate
Boundaries are not
easy to identify.
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They can be in the
sea, on land or at the
edges of continents.
Three types of plate
boundaries.
Compare the characteristic geologic activities that occur
along the three types of plate boundaries
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Divergent Boundaries
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Plates are moving apart.
The Asthenosphere
moves up to fill the gap
and form new oceanic
plate.
Most are found in the
oceans.
The rift valley is the
point were the plate
separates.
Compare the characteristic geologic activities that occur
along the three types of plate boundaries
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Convergent Boundaries
 Is a collision zone between two
plates.
3 types of collisions
 One type is a subduction, in which
one plate slips under another
forming a deep ocean trench.
 Second, two continental plates
collide and form tall mountain
ranges.
 Third, two ocean plates collide and
form a ocean trench and island arch
along the edge
Compare the characteristic geologic activities that occur
along the three types of plate boundaries
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Transform
Boundaries are
Two plates are
sliding past
each other.
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Explain the possible role of convection
currents
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Causes of plate motion
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A convection current causes the
plate movement.
The circular movement pulls
and pushes the plate to cause
the movement.
The heat is generated in the
core and moved to the surface
by convection
Summarize the theory of Micro-plate
terranes
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Microplate Terranes is a
theory that explains how
the continents formed.
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Seafloor spreading carries
small terranes across the
sea floor until it hits a
subduction zone and is
pulled off and pushed
onto another land form.