Earth Materials and Processes : ENDOGENIC PROCESS
Content Standard:
The learners demonstrate an understanding of:
geologic processes that occur within the Earth and
the folding and faulting of rocks
2. •Processes that is formed
or occurring beneath
the surface of the Earth.
ENDOGENIC PROCESS
3. a mixture of molten
rock, minerals and
gases.
This mixture is usually made up of a hot
liquid base called the melt, minerals
crystallized by the melt, solid rocks
incorporated into the melt from the
surrounding confines and dissolved
gases.
MAGMA
4. originates in the lower part of
the Earth’s crust and in the
upper portion of the mantle
known as asthenosphere.
MAGMA
7. • At about 30 to 65 km below the earth’s surface, the
temperature is high enough to melt rocks into magma. The
reason why it is difficult to drill holes deep into the crust is
that the temperature rises about 30 degree for every
kilometer.
• The asthenosphere which is between 100 to 350km deep is
so hot that most of the rock is melted . The melt flows very
slowly because it is under intense pressure. Magma reaches
temperatures between 600 degree 140 degree Celsius.
How Are Magmas Formed ?
9. • Deep in the Earth, nearly all magmas contain gas dissolved
in the liquid, As magma rises at the surface of the Earth,
pressure is decreased and the gas forms a separate vapor
phase. This is somewhat similar to carbonated beverages
which are bottled at high pressure.
• When magma emerges on the surface of the Earth, it is
called lava. Lava spilling over or erupting from craters is
usually bubbly, a sign that gases are escaping.
Gases in Magma
10. •Viscosity is the resistance to flow
(an antonym for fluidity).
• Magma with higher silica content has higher viscosity. Viscosity
increases with increasing silica concentration in the magma.
• Magma with low temperature has higher viscosity than those
with high temperature. Viscosity decreases with increasing
temperature of the magma.
Viscosity of Magmas
11. • Magma leaves the confines of the asthenosphere and
crust in two major ways; an intrusion or extrusion.
• Magma can intruded into low-density area of another
geologic form such as a sedimentary rock. When it cools
and hardens, this intrusion develops into an pluton
commonly know as an igneous intrusive rock.
• Magma rises towards the Earth`s surface where are less
dense surrounding rocks and when a structural zone allows
movement.
Magma Escape Routes
15. • Magma develops within the upper mantle and crust where the crust
where the temperature and pressure conditions favor the molten state.
Magma collects in areas called magma chamber.
• There pool of magma in a magma chamber is layered. The least dense
magma rises to the top. The densest magma sinks at the bottom of the
chamber.
• During an eruption, gases, ash and light-colored rocks are emitted from
the least dense top layer magma chamber. Dark, dense volcanic rock
from the lower part of chamber may be released later.
Magma Chamber
17. 1) Decompression Melting
Ways to Generate Magma
involves the upward movement of the
Earth’s mostly solid mantle
this hot material rises to an area of lower
pressure through the process of
convection.
19. 2) Transfer of Heat
Ways to Generate Magma
Happens when hot, liquid rock intrudes
into the Earth’s crust. As the liquid rock
solidifies, it loses this heat and transfers it
to the surrounding crust. This is similar to a
hot fudge poured over cold ice cream.
21. 3) Flux Melting
Ways to Generate Magma
It occurs when water or carbon
dioxide added on rocks these affects
the melting point of rock when added
with water beneath the earth it
generates magma.
23. Types of Magma
1. Felsic Magma
2. Intermediate Magma
3. Mafic Magma
4. Ultramafic Magma
25. This type of magma has viscosity
level there has low in iron but high
in potassium and sodium this form
makes granite rocks.
Felsic Magma
26. This normally found in
volcano that erupts, after
the eruption it releases a
lava that has high silica
and very viscous/ it
commonly produced
Andesite Rock.
Intermediate Magma
27. Mafic magma has relatively low silica
content but high in iron and
magnesium. This magma has a low
gas content and low viscosity. Mafic
magma has high average
temperature which contributes to its
low velocity. Low velocity means that
mafic magma is the most fluid of all
magma types.
Mafic Magma
29. Today our planet is to cool, for
ultramafic magma to form. This
is a probably a good thing,
since ultramafic magma would
be the hottest and fastest
flowing magma.
Ultramafic Magma
33. 1) Stress
Rock Deformation
the force that could create deformation
on rocks in their shape and/ volume.
Great forces from several directions may act on the
lithospheric plates causing them to move. Although this
crustal plates are elastic solid, they are subjected to great
forces such as pulling, pushing or squeezing.
34. 1) Lithostatic stress
Rock beneath the Earth’s surface
experiences equal pressure exerted
on it from all directions because the
weight of the overlying rock.
It is like the hydrostatic stress (water pressure) that a person
feels pressing all over his body when diving down deep in the
water.
Kinds of Stress
35. 2) Differential stress
stress on rocks that are caused by an
additional due to unequal stress due to
tectonic forces.
3 Kinds are
a) Tensional stress (stretching)
b) Compressional stress (squeezing)
c) Shear stress
Kinds of Stress
36. a) Tensional stress (stretching). This is when rock is stretched apart
or pulled apart. Where crustal plates diverge, rocks are pulled
apart.
b) Compressional stress (squeezing). This is when rock is pressed,
squeezed or pushed together . It’s like a car caught in the
middle of a long pile up on the highway. Where crustal plates
collide, rocks are compressed or pushed.
c) Shear stress which results in slippage and translation. With
shear stress, the rock is being pulled in opposite directions. It is
similar to the motion between individual playing cards when
the top of the stack is moved relative to the bottom.
Types of Differential Stress
38. a) Elastic deformation
For small differential stresses, less than the yield strength,
rock deforms like a spring. It changes in shape by a very
small amount in response to the stress. The deformation is
not permanent. This deformation is reversable. The rock can
return to its original shape.
b) Brittle deformation or Fracture
Near the Earth’s surface rock behave in its familiar brittle
fashion. If a differential stress is applied that is greater than
the rock’s yield strength, the rock fractures. Fracture is an is
an irreversable strain wherein the rock breaks.
Types of Deformation
40. 4) Faults
Rock Deformation
are extremely long and deep
break or large crack in a rock
a result of continuous pulling
and pushing.
41. a) Dip-slip fault (Normal fault)
b) Strike-slip fault
c) Reverse (or thrust) fault
Types of Faults
42. 1) Dip-slip fault (Normal fault)
occurs when brittle rocks are stretched-tectonic
tensional forces are involved and the movement of
blocks or rock is mainly in the vertical direction (sinking
and rising).
For dip-slip faults, the block lying on the top of the fault
surface is referred to as the hanging wall while the
one below is referred to as the footwall.
Normal fault tends to dip about 600. The hanging wall
has moved downward relative to the footwall.
Types of Faults
43. Normal faults are the chief structural components of many
sedimentary rift basins like the North Sea where they have
major significance for hydrocarbon exploration.
45. 2) Strike-slip fault
occurs when brittle rocks are sheared (the
opposing tectonic forces are at right angles to
compression and tension directions) and the
movement of blocks of rock is chiefly in the
horizontal direction.
If the far side of the fault moves to the left
relative to an observer it is called “sinistral strike-
slip fault” (left-lateral).
Types of Faults
47. 3) Reverse (or thrust) fault
occur when brittle rocks are pushed
(the tectonic forces are
compressional).
Types of Faults
50. Philippines has many faults. One of this is the Marikina Valley
Fault System that contains two major segments: the West Valley
Fault and the East Valley Fault.
The West Valley Fault which is believed to impact as the BIG
ONE is a dominantly strike-slip fault that extends from Dingalan,
Aurora in the North and runs through the provinces of Nueva Ecija,
Bulacan (Dona Rosario Trinidad, Norzagaray, San Jose del Monte),
Rodriguez, Rizal and the cities of Metro Manila which include
Quezon City, Marikina, Pasig, Makati, Parañaque, Taguig and
Muntinlupa and the provinces of Laguna (San Pedro, Biñan, Sta.
Rosa, Cabuyao, Calamba) and Cavite (Carmona, Gen. Mariano
Alvarez, Silang) that ends in Tagaytay. The eastern segment
known as the East Valley Fault moves in an oblique dextral motion.
It affects the area of Rodriguez and San Mateo Rizal.
51. Deformation
Rocks buried deep within the Earth’s crust
behave differently when subjected to differential
stress. It is impossible to produce fracture in rocks
the way it is at the Earth’s surface. Rocks become
thicker under compressional stress and thinner
under tensional stress. Rock layers tend to bend
and go out of shape. The high temperature
condition makes a rock softer, less brittle and more
ductile.
53. FOLDS
promoted by high temperature and pressure at
great depth.
When rocks deform in a ductile manner, instead of
fracturing to form faults or joints, they may bend or
fold and the resulting structures are called folds.
Kinds of folds:
1. Monoclines
2. Synclines
3. Anticlines
54. 1) Monocline
are the simplest types
of folds. Monoclines
occur when the
horizontal layers are
bent upward so that
two limbs of the fold
are still horizontal.
Kinds of Folds
55. 2) Syncline
are folds structures when
the original rock layers
have been folded
downward and the two
limbs of the fold dip
inward toward the hinge
of the fold.
Kinds of Folds
56. 3) Anticline
are fold structures
formed when the
originally rock layers have
been folded upward and
the two limbs of the fold
dip away from the hinge
of the fold.
Kinds of Folds
57. Synclines and anticlines usually occur
together such that the limb of a syncline is also
the limb of an anticline. The anticline may form
mountains, hills or ridges while the syncline may
from valleys.
Faults and folds are geological structure
that result from the response of rocks to
tectonic stresses induced by plate movements.
59. REFERENCE:
• Moncada, M. et. al (2016). Earth and Life Science for Senior High School.
Disclaimer:
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