2. OBJECTIVES
List different types of tresses that cause different type of
deformation
Compare the different types of folds and the conditions
under which they form.
Compare fractures and faults and define how are they
related to earthquakes.
Compare how mountains form and at what types of plate
boundaries.
3. WHAT CAUSES ROCKS DEFORMATION?
Rocks are solid, but will respond when force are
applied to them.
When rock deformation is being discussed the
term stress is used rather than pressure.
4. WHAT IS A STRESS?
Stress is the force applied to a rock.
In Geology stress is the force per
unit area that is placed on a rock.
6. CONFINING STRESS
Confining stress happens as weight of all the
overlying rock pushes down on a deeply buried
rock.
The rock is being pushed in from all sides,
which compresses it.
7. COMPRESSION STRESS
Compression stress squeezes
rocks together.
Compression causes rocks to fold
or fracture.
Compression is the most common
stress at convergent plate
boundaries.
8.
9.
10. TENSION STRESS
Tension stress pulls rocks apart.
Tension causes rocks to lengthen
or break apart.
Tension is the major type of stress
found at divergent plate
boundaries.
11.
12.
13. SHEAR STRESS
Shear stress happens when forces slide
past each other in opposite directions.
This is the mostcommon stress found at
transform plate boundaries.
16. FOLDS
When rocks are experiencing stress deform
plastically, the rock crumple into folds.
When a rock bends without breaking, it folds..
Folds are made up when two plates the earth’s
crust collide.
18. MONOCLINE
A monocline is a simple “one step“ bend in
the rock layers.
In a monocline, the oldest rocks are still at
the bottom and the youngest are at the top.
19.
20.
21. ANTICLINE
An anticline is a fold that arches upward.
The rocks dip away from the center of the fold.
The oldest rocks are found at the center of an
anticline. The youngest rocks are draped over them
at the top of the structure.
22.
23.
24. When upward folding rocks form a circular
structure, that structure is called a dome. If the
top of the dome is eroded off, the oldest rocks
are exposed at the center.
25. SYNCLINE
A syncline is a fold that bends downward.
In a syncline, the youngest rocks are at the center. The oldest
rocks are at the outside edges.
When rocks bend downward in a circular structure, it is called
a basin.
28. FAULTS
The place where movement occurs along plate boundary.
Faults are fractures in Earth's crust where rocks on either side
of the crack have slid past each other.
Fault are cracks in earth’s crust where movement occurs on at
least one side .
31. NORMAL FAULT
Normal fault create space.
Two blocks of crust pull
apart, stretching the crust
into a valley.
32. REVERSE FAULTS
Reverse faults, also called
thrust faults, slide one block of
crust on top of another.
These faults are commonly
found in collisions zones,
where tectonic plates push up
mountain ranges such as the
Himalayas and the Rocky
Mountains.
33. STRIKE-SLIP FAULTS
Strike-slip faults indicate rocks are sliding past each other
horizontally, with little to no vertical movement. Both the
San Andreas and Anatolian Faults are strike-slip.
34.
35. MOUNTAINS
Mountains are magnificent and inspiring features. Just thinking of
mountains conjures up beautiful images of places like the Rockies, the
Andes, Hawaii and the Alps.
But not all mountains are the same. Though they all take a very long
time to form, mountains are created in different ways depending on
where they are on Earth. Some mountains are created by land pushing
together, while others are formed over hotspots on Earth.
37. PLATE BOUNDARIES
As plates interact, a boundary between these
plates exist or locations where two tectonic
plates meet.
38. THREE TYPES OF PLATE
BOUNDARIES
Divergent boundary
Convergent boundary
Transform plate boundary
39. DIVERGENT BOUNDARY
A divergent boundary occurs when two tectonic plates move away
from each other. This most often takes place at ocean ridges.
Volcanic activity is the most common seen in a divergent boundary
As the plates separate from each other new crust is being made.
41. CONVERGENT BOUNDARY
When two plates come together, it is known as
a convergent boundary.
Convergent plate boundaries are locations
where lithospheric plates are moving towards
one another. The impact of the two colliding
plates buckles the edge of one or both plates up
into a rugged mountain range, and sometimes
bends the other down into a deep seafloor trench.
42.
43. TRANSFORM PLATE BOUNDARIES
Two plates sliding past each other forms a transform plate
boundary.
A boundary were plates are slide past each other.
At this type of boundary the only effect is the earth quake.
44.
45.
46. Plate
Boundaries
Type of Stress Kind of
Deformation
Types of that
deformation
Example
Divergent
Boundary
Tensional
Stress
Fracture Fault (normal
fault)
West Africa
rift Valley
Convergent
Boundary
Compressional
Stress
Fold
Fracture
(It can be any
type of fold)
Fault (Reverse
Fault)
Himalayan
Mountain
Andes
Mountain
Transform
plate
boundaries
Shear stress Fracture Fault (Strike
Slip Fault)
San Andrea’s
Fault
47. BY HENRY DAVID THOREAU
“You must love the crust of the earth on which you
dwell more than the sweet crust of any bread or
cake. You must be able to extract nutriment out of a
sand-heap. You must have so good an appetite as
this, else you will live in vain.”
Editor's Notes
The response may involve tiny changes in the volume and shape of the rock, including slow flow. Such changes are called deformation.
The rock will not deform because there is no place for it to move.
A fold is a rock formation that has been made by flat rocks that has been deformed through the stress.
Places like west of Rocky mountains are affected by normal faults like south Oregon, and southwestern Idaho, eastern California. Western euthah, and the entire of state of neveda.
The Basin and Range Province in North America and the East African Rift Zone are two well-known regions where normal faults are spreading apart Earth's crust.
Canadian Rockies, rocky mountain, Appalachian mountains, are types of mountain created by reverse faults.
Let's take a closer look at the mountain building process to better understand how these incredible structures come to be.
The earth is like a puzzle, and all the pieces that make up this puzzle is called tectonic plates,
As tectonic plates of the earth or giant piece of the earth crust move and crash into each other. Plate boundaries are formed.
This type of plate boundary is caused by a tension stress and then will causes a fault. As the plates separates from each other volcanic activity is one of the most common result but this happens when a divergent boundary is in the ocean floor.
If divergent boundary occurs in the land or in the continent a rift valley is a result. And African rift valley is one of the example.
Convergent boundary is caused by compression stress. Remember in divergent boundary new crust is being made by the splitting of a tectonic plate. But in convergent boundary is two tectonic plates are being joined together forming a new crust. Through the compression stress two plates are being pushed to each other to become one and in this type of boundary is were mountains builds up.
The plate collisions that occur in these areas can produce earthquakes, volcanic activity and crustal deformation.
As plates collide to each other they will form high mountain ranges like the Himalayas mountain.
Another way of plates can interact is by sliding past each other and this result in a transform plate boundary. Tectonic plates are grinding past each other as they move in opposite direction.
The most famous example of transform boundary is the San Andreas fault in California. The fault is the edges of pacific plate and the North American plate. The pacific plate is moving northwest at the rate of several centimeters per year. At this type of boundary the only effect is the earth quake.
The following videos are one of my references it is not included in the presentation.
Thank you for looking. Hope this presentation is helpful