The document discusses various concepts related to plate tectonics and structural geology. It describes continental drift theory, which proposes that continents were once joined together in a supercontinent before drifting apart. It also explains key concepts such as tectonic plates, plate boundaries, earthquakes, seismic waves, volcanoes and volcanic landforms. The theory of plate tectonics provides a framework for understanding geological phenomena by describing the movement of rigid tectonic plates that make up Earth's outer shell.

2.  The movement of the solid parts of
the earth.
 These movements can be:
Subsidence: sinking of the crust or the
solid part towards the mantle.
Uplift: rising of the crust or the solid
part.

3.  Rigid sections of the lithosphere that moves
as a unit.
› Convergent Boundary – a boundary which two
plates move towards each other.
› Divergent Boundary – a boundary which two
plates move apart.
› Transform Plate Boundary – a boundary when
two plates slide past each other.

4.  The solid portion of the earth’s crust.
 Crust – the outer portion of the Earth.
› Continental crust – the thick part of the Earth’s
crust not located under the ocean (less dense)
› Oceanic Crust – the thinner part of the Earth’s
crust located beneath the ocean.

5.  Continental Drift Theory
 Proposed by ALFRED WEGENER in 1912.
 The theory explains that the continents we
know today was once a one big super continent
knows as Pangea and surrounded by a huge
body of ocean called the Pnathalassa.
 This theory has given way to a lot of
breakthroughs in geology and scientific history
such as the formulation of other theories and
the process of mountain formation.

6. CONTINENTAL DRIFT
THEORY

7. CONTINENTAL DRIFT
THEORY

8. CONTINENTAL DRIFT
THEORY

9.  The fit of the continents.
 The similarity of fossils in different continents.
 The similarity of rock type and age along the
matching coastlines.
 The continuity of geologic features from
continent to continent.
 The presence of coal seams in Antarctica.
 The presence of Tillites in different continents.

10. Seafloor Spreading Theory

11.  Proposed by HARRY HESS of Princeton
University.
 The theory accounts about the movement of the
continents by the formation of the new oceanic
crust which pushes away continental crust.
 The theory is a great support to the preceding
one which is the Continental Drift theory.

12. Plate Tectonics Theory

13.  The theory of plate tectonics provides a useful way to
explain the causes of earthquakes, volcanoes, oceanic
mountain ranges, and other geological features and
events.
 The theory explains that the outer shell of the earth is
made up of thin, rigid plates that move relative to each
other. The theory of plate tectonics was formulated during
the early 1960s, and it revolutionized the field of geology.
Scientists have successfully used it to explain many
geological events, such as earthquakes and volcanic
eruptions as well as mountain building and the formation
of the oceans and continents.

14.  Divergent Plate Boundary: Formed when two
plates are moving away from each other.
 Convergent Plate Boundary: Formed when two
plates are moving towards each other.
 Transform Plate Boundary: A plate boundary
where two neighboring plates are neither
spreading apart nor colliding with each other.
Instead, the plates are sliding past each other.

15.  Crack in the cr
ust of the earth
along which
there has been
movement of
the rocks on
either side of
the crack.

16.  Normal Fault: A
normal fault forms
as a result of
tension. The rock
layers in the
Earth's crust are
pulled apart, and
gravity causes
one section to
move downward
in relation to the
other.

17.  Dip – Slip
Fault/Reverse
Fault: A reverse
fault forms as a
result of
compression. The
rock layers in the
Earth's crust are
squeezed together,
and the force
pushes one section
upward in relation
to the other.

18.  Strike – Slip Fault:
A strike-slip fault
forms when the
rock layers on
opposite sides of a
fault slide past each
other horizontally.
This type of fault is
sometimes called a
tear, wrench, or
transcurrent fault.

19.  A bend in a rock layer
caused by forces
within the crust of the
earth. The forces that
cause folds range
from slight differences
in pressure in the
earth’s crust, to large
collisions of the crust’s
tectonic plates.

20.  An earthquake is a sudden shaking or
vibration in the earth’s crust. The crust is
divided into sections, called plates, which
continually move in relation to each other
and are bordered by faults. When plates
suddenly move past each other, the built-up
strain is released along the fault, and the
rock fractures.
 An earthquake also can be triggered by
molten rock moving up into the chamber of a
volcano before eruption.

21. Seismic wave is the energy wave generated by an
earthquake or an artificial motion.

22.  Body Waves: Seismic waves that travel through the
earth’s interior.
 P – Waves (Primary/Push – pull): They travel through
the earth by pushing rocks in the direction they are
traveling. They are almost twice as fast as the S – waves
and can travel through all states of matter.
 S – Waves (Secondary/Shear): They travel through the
earth by displacing rocks at right angles to their direction
of travel. They cannot pass through fluids.
 Surface Waves: Seismic waves that travel in the surface
or subsurface layers of the crust.
 Rayleigh Waves: It shakes the ground up and down.
 Love Waves: It shakes the ground side by side.

23.  A volcano is an opening in the crust of a
planet from which lava flows. A volcanic
mountain forms when magma from the
planet’s mantle forces its way through the
crust in the form of lava or ash and then
forms a cone on the planet’s surface. On the
earth, volcanoes form near hot spots within
the earth’s crust or in regions over
subduction zones at the boundaries of
tectonic plates.

24. Crater: A crater is the
bowl-shaped depression at
the top of a volcano
through which lava and/or
ash and hot gases are
ejected when the volcano
erupts. A meteorite crater
is the depression formed in
the ground by the impact
of a meteorite.
Vent: The passage way of
the magma through the
crater and out of the
surface as lava.

25. Magma Chamber: Magma is
molten rock material that
exists within the Earth in its
lower mantle and crust.
Magma that flows onto the
Earth’s surface through
volcanoes and rifts in its crust
is called lava and forms
extrusive igneous rocks.
Caldera: A caldera is the
collapsed crater of a volcano.
It forms when an eruption
empties the magma chamber
that lies under the crater and
the top of the volcano
collapses under its own
weight.

26. Lava Flow: A lava flow
is a deposit of rock
material that flows out of
the vent of a volcano.
Lava is molten rock, or
magma, that originates
within the mantle of a
planet. Typically, the
magma contains many
gases and is ejected
forcefully. This type of
material settles to
become an ash flow.

27. 1. Fissure Volcano: A
fissure volcano, also
called a fissure vent, is a
long crack in the Earth’s
surface through which
magma pours out. The
flows from fissure
volcanoes produce thick
sheets of basalt that can
extend for thousands of
square kilometers. The
Columbia Plateau in the
northwest United States
and the Deccan Plateau in
India are examples of

28. 2. Shield Volcano: A
shield volcano is formed
from recurring flows of
fluid, basaltic lava rather
than from a single
explosive eruption.
Because basaltic lava is
thin and runny, these
flows gradually build up
gently sloping, shieldlike
mounds with wide bases.
Volcanic shields may be
either small or large, and
the largest shield
volcanoes are many times
larger than the largest
composite volcanoes.

29. 3. Dome Volcano: A
dome volcano, sometimes
called a plug dome, is
made up of viscous,
acidic, extruded lava that
fills a summit crater. Hard
spikes of solidified lava
can block the vents,
eventually resulting in
powerful, explosive
eruptions. Dome
volcanoes tend to have
steep, somewhat convex
sides. Examples of dome
volcanoes include Lassen
Peak, in the Sierra
Nevada, and Mount
Pelée, on Martinique

30. Cinder Cone: A cinder
cone is a volcano that
is formed primarily of
basaltic cinder and
loose volcanic ash
deposited by a
pyroclastic, or
explosive, eruption.
Because cinder cones
are formed from loose
material instead of lava,
they are subject to
erosion and are usually
much smaller than
composite volcanoes.

31. Composite Volcano: A
composite volcano, also
called a stratovolcano, is
formed from a combination of
nonexplosive lava flows and
pyroclastic, or explosive,
eruptions. The successive
layers of lava and ash solidify
and accumulate additional
mass over time. Composite
volcanoes are often
symmetrical and conical in
shape, with slopes that are
higher and steeper than
those of shield volcanoes.
Examples of composite
volcanoes include Mount Fuji,
in Japan, and Etna, in Sicily.

32. Caldera: A caldera is a round or
oval-shaped low-lying area that
forms when the ground collapses
because of explosive eruptions.
An explosive eruption can
explode the top off of the
mountain or eject all of the
magma that is inside the volcano.
Either of these actions may cause
the volcano to collapse. Calderas
can be bigger than the largest
shield volcanoes in diameter.
Such volcanic features, if
geologically young, are often
outlined by an irregular, steep-
walled boundary (a caldera rim),
which reflects the original ringlike
zone, or fault, along which the
ground collapse occurred. Some
calderas have hills and mountains
rising within them, called
resurgent dome, that reflect
volcanic activity after the initial
collapse.