Download 1. Describe completely the following folds: a. Anticline – It is caused

1. Describe completely the following folds:
a. Anticline – It is caused by rock layers folding. In an anticline the oldest layers of
rock are found at the core of the fold. The youngest layers of rock are found of
the outside of the fold. It looks like the letter “A”.
b. Syncline – It is caused by rock layers folding. In a syncline the youngest layers of
rock are found at the core of the fold. The oldest layers of rock are found on the
outside of the fold. They usually look like rock layers that are arched upward
like a bowl.
2. What causes a fold to occur in the rock layer? Compression causes folding to occur in
the rock layers.
3. What places stress on the rocks of tectonic plates? The movement of the tectonic
plates puts stress on the rock layers.
4. What is meant by the term deformation? Deformation is when rocks change shape and
size due to stress.
5. If the geology of an area is dominated by tensional tectonic forces, what two types of
mountains would you expect to find? Volcanic mountains and fault block mountains
6. Describe completely the following types of faults:
a. Strike-slip fault – In a strike-slip fault, the fault blocks move past each other
horizontally. They are formed when rock is under shear stress. Shear stress is
stress that pushed the rocks in opposite but parallel directions. They are
common along transform boundaries and can produce earthquakes.
b. Normal fault –Normal faults form when the rock is under tension. Tension is
stress that stretches or pulls rock apart. The hanging wall moves down relative
to the footwall. These types of faults are common along divergent boundaries.
c. Reverse fault – Reverse faults form when when rock undergoes compression.
Compression is stress that squeezes or pushed rock together. The hanging wall
moves up relative to the footwall. These type of faults are common along
convergent boundaries where two plates collide.
7. Explain completely the following terms in regards to faults:
a. Shear stress – Shear stress pushes rocks in parallel but opposite directions. They
are found in strike-slip faults.
b. Tension – Tension is stress that that stretches or pulls rock apart. They are found
in normal faults.
c. Compression – Compression is stress that squeezes or pushes rock together.
They are found in reverse faults.
8. What is meant by the term “failed rift system”? A failed rift system is one that doesn’t
form. It is caused by extensional forces and is the result of continental rifting that
failed to continue to the point of break-up.
9. Over long periods of time, tectonic forces can cause rocks to fold. What kind of stress
causes folding? Compression causes folding.
10.Describe the following types of mountains completely. Be sure to explain how they are
formed and what tectonic plate boundaries they are usually associated with.
a. Folded mountains – Folded mountains form when rock layers are squeezed
together and pushed upwards. They usually form at convergent boundaries
where plates collide.
b. Volcanic mountains – Volcanic mountains form when melted rock (lava) erupts
onto Earth’s surface. Many major volcanic mountains are located at convergent
boundaries. They can form on land (convergent boundaries)or the ocean floor
(divergent boundaries).
c. Fault-block mountains – Fault-block mountains form when tension makes the
lithosphere break into many normal faults. Along the faults, pieces of the
lithosphere drop down compared to the other pieces. The pieces left standing
form the fault-block mountains.
11.What happens to rocks during deformation? Rocks change their size and shape during
deformation.
12.Explain the following terms:
a. Fault Plane – The location where two fault blocks meet is called the fault plane.
It’s the actual fault, or crack, in the rock layer which creates the fault blocks.
b. Hanging Wall – The hanging wall is the fault block that is above the fault plane.
c. Foot Wall – The foot wall is the fault block that is below the fault plane.
13.What happens when stress causes a normal fault? The hanging wall drops due to
gravity.
14.What kind of movement occurs along a reverse fault? The hanging wall moves up due
to the compression.
15.In an anticline, where are the youngest and oldest layers of rock found? The youngest
layers of rock are found on the outside slopes going down and the oldest layers of rock
are found at the core of the fold
16.In a syncline, where are the youngest and oldest layers of rock found? The youngest
layers of rock are found at the core of the fold and the oldest layers of rock are found
on the outside of the fold.
17.Explain how forces from tectonic plate movement can build these three types of
mountains : folded mountains, fault-block mountains, and volcanic mountains.
 The movement of tectonic plates produces stress that causes rock to deform
(strain). Strain can result in folds and/or faults. Faults can create fault block
mountains after a very long time of uplift and erosion. Large folds can create
folded mountains. When two plates come together at a convergent boundary,
subduction can cause volcanic activity, resulting in volcanic mountains.
 Fault block mountains can also form when tension from divergent boundaries
causes faults and the blocks of rock on either side of the fault move up or down
relative to the other block.
 Sometimes volcanic activity beneath the Earth can cause uplift of the crust, and
the lava can build up into a mountain over time.