Name_____________________________________________D______________P_____
Fossils and Faults
Activity
Background – Stress
The movement of Earth’s plates creates enormous forces that squeeze or
pull the rock in the crust. Since the outer part of the Earth crust is relatively
cold, when it is stressed it tends to break. Any force that acts on rock to
change its shape or volume is called _______________. Stress adds energy to the rock. The
energy is stored in the rock until it changes shape or breaks. There are 3 basic types of stress
acting upon the Earth’s crust: tension, compression and shearing.
________________pulls on the crust, stretching rock so that it becomes
thinner in the middle. *We call this a ___________ boundary when
discussing plate tectonics. _____________________ Fault
______________________squeezes rock until it folds or breaks.
*We call this a _________________________ boundary when discussing
plate tectonics. _____________________ Fault
______________________ pushes a mass of rock in two opposite
directions *We call this a _______________boundary when discussing
plate tectonics._____________________ Fault
Background - Faults
When enough stress builds up in rock, the rock breaks, creating a fault. These
breaks are called ____________________________. Most faults occur along plate
boundaries, where the forces of plate motion push or pull the crust so much that the
crust breaks. There are three main types of faults: normal faults, reverse faults, and
strike-slip faults. The most obvious result of movement along a fault is an
_____________________. Earthquakes tend to happen along the boundaries between
plates ________________ causes a normal fault. In a _____________________
___________, the fault is at an angle, and one block of rock lies above the fault while the
other block lies below the fault. The block of rock that lies above is called the
_____________________________ The rock that lies below is called the
________________________________. _____________________ causes reverse faults.
Name_____________________________________________D______________P_____
A ____________________ fault has the same structure as a normal fault, but the blocks
move in the opposite direction. ____________________creates strike-slip faults. In a
_______________-_______________ fault, the rocks on either side of the fault slip past
each sideways, with little up or down motion.
Background - Fossils and Superposition
The ______________ ______ ______________________ states
that in undisturbed rock layers the oldest rock is on the bottom and the
youngest is on the top. This makes it simple to determine the relative age
of fossils in the different layers of rock. The rock layers, however, are
often disturbed (mixed) because of plate motion. Faulting and folding
take old rock and push it on top of young rock. Over millions of years, the forces of plate
movement can change a flat plain into landforms such as anticlines and synclines, folded
mountains, fault-block mountains, and plateaus. A fold in rock that bends upward into an
arch is an ________________________. A fold in rock that bends _________________
to form a ________________ is a _________________. Anticlines and synclines are
found on many parts of the Earth’s surface where _____________________ forces have
folded the crust. Plate movements and stress also create reverse, normal, strike slip and
thrust faults. The constantly shifting plates make it difficult to date the age of the
Earth’s rocks. A paleontologist (scientist that studies fossils) has to know geology to read
the fossil record of life on earth.
Directions
1. Color the fossils and faults model according to the color key provided.
2. Cut out the fossils and faults model and form into a box with the surface features
on the top.
3. Use the shaded tabs to tape the corners together.
4. Carefully cut the model in half along the
dotted line.
5. Cut out and tape the fault face pieces to
the open fault face of the two halves.
6. Label the two halves as hanging wall
and footwall as shown below.
7. Use the model to answer the questions.
Name_____________________________________________D______________P_____
Fossils and Faults
Activity
Background – Stress
The movement of Earth’s plates creates enormous forces that squeeze or
pull the rock in the crust. Since the outer part of the Earth crust is relatively
cold, when it is stressed it tends to break. Any force that acts on rock to
change its shape or volume is called stress. Stress adds energy to the rock.
The energy is stored in the rock until it changes shape or breaks. There are
3 basic types of stress acting upon the Earth’s crust: tension, compression and shearing.
Tension pulls on the crust, stretching rock so that it becomes thinner
in the middle. *We call this a divergent boundary when discussing
plate tectonics.
Compression squeezes rock until it folds or breaks.
*We call this a convergent boundary when discussing
plate tectonics.
Shearing pushes a mass of rock in two opposite directions *We call this a
transform boundary when discussing plate tectonics.
Background - Faults
When enough stress builds up in rock, the rock breaks, creating a fault. These
breaks are called faults. Most faults occur along plate boundaries, where the forces of
plate motion push or pull the crust so much that the crust breaks. There are three
main types of faults: normal faults, reverse faults, and strike-slip faults. The most
obvious result of movement along a fault is an earthquake. Earthquakes tend to happen
along the boundaries between plates
Tension causes a normal fault. In a normal fault, the fault is at an angle, and one
block of rock lies above the fault while the other block lies below the fault. The block of
rock that lies above is called the footwall. The rock that lies below is called the hanging
wall. Compression causes reverse faults. A reverse fault has the same structure as a
normal fault, but the blocks move in the opposite direction. Shearing creates strike-slip
faults. In a strike-slip fault, the rocks on either side of the fault slip past each sideways,
with little up or down motion.
Background - Fossils and Superposition
The Law of Superposition states that in undisturbed rock
layers the oldest rock is on the bottom and the youngest is on the top. This
makes it simple to determine the relative age of fossils in the different
layers of rock. The rock layers, however, are often disturbed (mixed)
because of plate motion. Faulting and folding take old rock and push it on
top of young rock. Over millions of years, the forces of plate movement
Name_____________________________________________D______________P_____
can change a flat plain into landforms such as anticlines and synclines, folded mountains,
fault-block mountains, and plateaus. A fold in rock that bends upward into an arch is an
anticline. A fold in rock that bends downward to form a valley is a syncline. Anticlines
and synclines are found on many parts of the Earth’s surface where compression forces
have folded the crust. Plate movements and stress also create reverse, normal, strike
slip and thrust faults. The constantly shifting plates make it difficult to date the age of
the Earth’s rocks. A paleontologist (scientist that studies fossils) has to know geology to
read the fossil record of life on earth.
Objective
1. Use a model of the earth’s crust to observe stress
and the fault types it can create.
2. To demonstrate how faulting can rearrange rock so
the youngest is not always found on top.
3. Examine the way that faulting mixes the rock layers
and makes it difficult to read the fossil record.
Materials





crayons, markers, or colored pencils
scissors
tape
metric ruler
fossils and faults model sheet
Directions
7. Color the fossils and faults
model according to the color key
provided.
8. Cut out the fossils and faults
model and form into a box with
the surface features on the top.
9. Use the shaded tabs to tape the
corners together.
10. Carefully cut the model in half along the
dotted line.
11. Cut out and tape the fault face pieces to
the open fault face of the two halves.
12. Label the two halves as hanging wall
and footwall as shown below.
7. Use the model to answer the questions.