Geo-Mini Labs
Name___________________________Blk ___ Date ______ NB#___
Pangaea Overview
The Earth’s crust is not a solid shell. It is made up of interconnecting pieces called tectonic (crustal material)
plates that fit together like a puzzle. They move atop the underlying mantle, hot flowing rock. By examining
evidence such as similar rock layers in various places, fossilized desert belts, the distribution of fossils, and the
physical shapes of continents, scientists have concluded that the Earth’s continents were once all connected
to form a “supercontinent” called Pangaea that was surrounded by an enormous ocean. In this activity,
students will use the different kinds of evidence to reconstruct how the Earth may have looked approximately
220 million years ago.
1. Define Tectonic:
2. List four pieces of evidence that scientists have examined to create the Theory of Pangaea:
Did You Know?
 Tectonic plates are made of both continental and oceanic crust. The land we see is the continental
crust, about 30 kilometers (19 mi) thick. Under the sea, the oceanic crust is much thinner, about 8 to
10 kilometers (5 to 6 mi) thick.
 Plates move about 8 centimeters (3 in) per year. That’s about as fast as a fingernail grows in a year!
 The tallest mountains in the world are still growing. About 60 million years ago, the Himalayan
Mountains formed when the Indian Plate crashed into the Eurasian Plate. Today the two plates are still
colliding and the Himalayas continue to rise.
 Los Angles sits on the Pacific Plate that is moving northwest and San Francisco sits on the North
American Plate that is moving southeast. Moving towards each other at the rate of 5 centimeters (2 in)
a year, someday these two cities could be neighbors!
3. Explain how any ONE of the above facts helps to support the Theory of Pangaea:
Understanding Plate Movement
Scientists now have a fairly good understanding of how the plates move and how such movements relate to
earthquake activity. Most movement occurs along narrow zones between plates where the results of platetectonic forces are most evident.
Geo-Mini Labs
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Types of plate boundaries
Divergent boundaries – (also called Tension or Normal Faults) where new crust is generated as the plates pull
away from each other. Divergent boundaries occur along spreading centers where plates are moving apart
and new crust is created by magma pushing up from the mantle. Picture two giant conveyor belts, facing each
other but slowly moving in opposite directions as they transport newly formed oceanic crust away from the
ridge crest. Perhaps the best known of the divergent boundaries is the Mid-Atlantic Ridge. This submerged
mountain range, which extends from the Arctic Ocean to beyond the south- ern tip of Africa, is but one
segment of the global mid-ocean ridge system encircling the Earth. The rate of spreading along the MidAtlantic Ridge averages about 2.5 centimeters per year (cm/ yr), or 25 km in a million years. This rate may
seem slow by human standards, but because this process has been going on for millions of years, it has
resulted in plate movement of thousands of kilometers. Seafloor spreading over the past 100 to 200 million
years has caused the Atlantic Ocean to grow from a tiny inlet of water between the continents of Europe,
Africa, and the Americas into the vast ocean that exists today.
4. Explain what Divergent boundaries do:
Convergent boundaries – (also called Compression or Reverse Faults) where crust is destroyed as one plate
pushes toward another. The size of the Earth has not changed significantly during the past 600 million years,
and very likely not since shortly after its formation 4.6 billion years ago. The Earth's unchanging size implies
the crust must be destroyed at about the same rate as it is being created, as Harry Hess surmised. Such
destruction (recycling) of crust takes place along convergent boundaries where plates are moving toward each
other, and sometimes one plate sinks (is subducted) under another. The location where sinking of a plate
occurs is called a subduction zone. The type of convergence -- called by some a very slow "collision" -- that
takes place between plates depends on the kind of lithosphere involved. Convergence can occur between an
oceanic and a largely continental plate, or between two largely oceanic plates, or between two largely
continental plates.
5. Explain what Convergent boundaries do:
Transform boundaries – (also called Shear of Strike Slip Faults) where crust is neither produced nor destroyed
as the plates slide horizontally past each other. The zone between two plates sliding horizontally past one
another is called a transform-fault boundary, or simply a transform boundary. The concept of transform faults
originated with Canadian geophysicist J. Tuzo Wilson, who proposed these large faults or fracture zones
connect two spreading centers (divergent plate boundaries) or, less commonly, trenches (convergent plate
boundaries). Most transform faults are found on the ocean floor. They commonly offset the active spreading
ridges, producing zig-zag plate margins, and are generally defined by shallow earthquakes. However, a few
occur on land, for example the San Andreas Fault zone in California. This transform fault connects the East
Pacific Rise, a divergent boundary to the south, with the South Gorda -- Juan de Fuca -- Explorer Ridge,
another divergent boundary to the north.
6. Explain what Transform boundaries do:
Geo-Mini Labs
Name___________________________Blk ___ Date ______ NB#___
Pangaea Layout
On the next clean pair of pages of your composition, label one page Today
and the other page Pangaea. Cut out BOTH SETS of the continents.
Separate into two piles. Layout the continental pieces on the Today page
as the continents can be seen on Earth today.
On the page labelled Pangaea, use the physical shape of continents to fit
the continent puzzle pieces into one landmass. Remember not all the
boundaries will touch, some continents may overlap some & there might
be areas of water separating some of them. Once you are sure the
landmasses are in the correct position, tape them down in your notebook.
7. What theory states the continents were at one time all connected?
8. What was that single land mass called?
9. Look at the shapes of continents and islands. What land- masses seem to fit together?
10. The prefix “pan” means all and the suffix “gaea” (geo) means earth. Therefore, what would Pangaea
mean?
Convection Current
Watch the sawdust in the beaker and the
wax in the lava lamp.
Illustrate what appears to be happening in
the beaker here in the drawing of the
beaker.
11. Describe what a convection current is and how it is powered in
the Earth.
12. The movement of the continental plates is powered by:
Geo-Mini Labs
Name___________________________Blk ___ Date ______ NB#___
Faults- Tectonic Movements
13. Using your piece of candy apply pressure as directed by the teacher and record your results, along with
your other two table partners on the table below:
Term
Definition
Schematic
Drawing of Milky Way
Two Plates
Two Plates
Two Plates
14. Discuss how the above stresses have impacted the world recently:
__________________________________________________________________________________________
15. Identify which tectonic movement is used to create the below landmasses:
Mountains
Valleys
Trenches
Ridges
16. What is the internal movement of the magma called and what role does it play in the faulting process: