Download "Dynamic Earth Guided Notes" (Plate Tectonics)

Name: ______________________________________________________ Date: _______________________ Period: ________________
Guided Notes – Dynamic Earth
Topic(s): Plate Tectonics

Alfred Wegner
- He is most remembered for advancing the theory of continental drift in 1912, which
hypothesized that the continents were slowly drifting around the Earth. His hypothesis
was controversial and not widely accepted until the 1950s.

Continental Drift Theory
- A theory posed in 1912 stating that the Earth’s continents move over time.
- Web Link for Animation:
http://www.suu.edu/faculty/colberg/hazards/platetectonics/18_Pangaea.html

Evidence of Plate Movement
1. Puzzle-piece shorelines of continents across oceans (i.e. South American and Africa).
2. Similar fossil species on distance continents across oceans.
3. Mountain ranges that seem to be continued on different continents across oceans.

Pangaea
- Pangaea: the SUPER CONTINENT (about 250 million years ago).
- Lithospheric Plates: Are pieces of the Earth's crust and uppermost mantle, together
referred to as the lithosphere. The plates are around 100 km thick on the
continents.

Plate Boundary
- The border between two different lithospheric plates. There are several types of plate
boundaries based on plate movement.

Types of Plate Boundaries
- Convergent
- Divergent
- Transform
- Passive

Convergent Plate Boundary
Definition: A plate boundary when two plates move TOWARDS one another.
- Example: The Himalayan Mountains
-
1. Ocean  Continent
~ Trench: A deep, underwater trough (ditch) created by one plate subducting
(moving beneath) another plate at a convergent boundary. (Marianas Trench).
~ Subduction Zone: A zone where one tectonic plate moves under another tectonic
plate at a convergent plate boundary. The denser plate always moves under
the less dense plate.
~ Web Links: www.youtube.com/results?search_query=challenger+deep+footage&sm=3
http://www.youtube.com/watch?v=FGzaUiutuRk
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
-
2. Ocean  Ocean
-
3. Continent  Continent
~ Example: Himalayas, Appalachians, Alps (mountains)
~ Regional Metamorphism: Formation of metamorphic rock bodies that are
hundreds of square kilometers in size.
Divergent Plate Boundary
Definition: A plate boundary when two plates move AWAY from one another.
- Example: Mid-Atlantic Ridge
-
1. Ocean  Ocean
~ Mid-Ocean Ridge: The long, narrow mountain range on the ocean floor; formed by
magma at divergent plate boundaries. Examples are  Iceland and the MidAtlantic Ridge.
~ Sea Floor Spreading: The process by which new oceanic crust forms along a midocean ridge and older oceanic crust moves away from the ridge.
~ Magnetic Reversals: An event that causes a magnetic field to reverse direction
or charge.
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-
2. Continental  Continental
~ Rift: Forms on continents when two continental plates move apart (divergent
boundary). Examples are  The Great Rift Valley in Africa.

Transform Plate Boundary
- Definition: A plate boundary made up of many strike-slip fault causing SIDE-BY-SIDE
lateral movement.
- Example: San Andreas Fault

Passive Plate Boundary (Margin)
- Definition: When two plates are MOTIONLESS (do not move).
- Example: Atlantic Coastline of North America

It’s not my FAULT!
- Fault Types
~ Normal
~ Reverse
~ Strike-Slip
 Right Lateral
 Left Lateral
Parts of a Fault
- Hanging Wall
~ Definition: The overlying block of a fault having an inclined fault plane.
(HINT: this is the wall you could hang a lantern on)

-
Foot Wall
~ Definition: The underlying block of a fault having an inclined fault plane.
(HINT: this is the wall you could stand your feet on.)
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
Normal Fault
- Definition: When the foot wall moves up and the hanging wall moves down due to tension
(pulling apart).

Reverse Fault
- Definition: When the foot wall moves down and the hanging wall moves up due to
compression (pushing together).

Strike-Slip Fault
- Definition: When two slabs of rock slide side-by-side
~ Right Lateral: When you’re standing on a fault line and the land across the fault
appears to be moving to the RIGHT.
~ Left Lateral: When you’re standing on a fault line and the land across the fault
appears to be moving to the LEFT.

PRACTICE
REVERSE FAULT
NORMAL FAULT
STRIKE-SLIP FAULT
REVIEW QUESTIONS
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Review Question #1
One would commonly find a trench along a _______________ plate boundary.
a. Passive
b. Divergent
c. Convergent (continent-continent)
d. Convergent (ocean-continent)
Review Question #2
A __________ fault is when the hanging wall moves UP and the foot wall moves DOWN.
a. Normal
b. Reverse
c. Strike-Slip
d. Really, really, really big
Review Question #3
Which of the following examples is of a DIVERGENT plate boundary?
a. Himalayan Mountains
b. Mid-Atlantic Ridge
c. San-Andreas Fault
d. Marianas Trench
Review Question #4
Which of the following is NOT evidence of the Continental Drift Theory?
a. Similar fossils found on multiple continents.
b. The outlines of the continents look like puzzle pieces to one another.
c. Cave drawings found in multiple continents.
d. Mountain ranges that seemed to mysteriously end.
Review Question #5
Who was the leading theorist of the Continental Drift Theory?
a. Alfred Wegner
b. Waldo
c. Old McDonald
d. The monster who lives in your closet
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