Transcript Folded Mountains

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Wegner’s Theory explains: Stated that Earth's
continents were once joined in a single
landmass and gradually moved or drifted
apart. i.e. Pangaea
Evidence of Wegener’s Theory
He provided evidence that the same fossils
and plants are evident on all continents
before being separated; Many people during
his time didn't believe him. Just after his
death in 1930 did people begin to accept the
theory of continental drift.
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Describes the quasi-periodic aggregation and
dispersal of Earth’s Continental crust. There
are varying opinions as to whether the amount
of continental crust is increasing, decreasing, or
staying about the same, but it is agreed that the
Earth's crust is constantly being reconfigured.
One complete supercontinent cycle is said to
take 300 to 500 million years.
Pangaea- Was a supercontinent that
existed during the late Paleozoic
and early Mesozoic eras, forming
about 300 million years ago
 Panthalassa- A.K.A. Panthalassic
Ocean was the vast global ocean
surrounding Pangaea during the
Mesozoic and Paleozoic
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A process by which material is added to a
tectonic plate or a landmass
Examples of the material would be either
sediment or igneous such as volcanic arcs,
seamounts.
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Continental rifts are locations of continental
crustal divergence, crustal thinning,
sedimentary basin formation, and often
thermal and igneous activity. As indicated,
they are diverse, complex and polygenetic.
Continental crust can only be thinned so far
and at some point and in some way seafloor
spreading takes over.
 Climate: Plate tectonics gives the basic
setting for Earth's climate. The only effect that
plate tectonics has on climate is through
volcanic emissions; Radioactivity in the Earth’s
mantle moving the crustal plates on the
surface. For example the
 Evolution: When plate tectonics shift,
the animals above the tectonic plates also shift
causing them have to adapt to wherever they
are taken. Sometimes destroying species.
Theory of
Plate
Tectonics
The Lithosphere
 The
rigid outermost shell on Earth
 It comprises the crust and the portion of
the upper mantle
The Asthenosphere
 The
highly viscous and mechanically
weak region
 Comprises of the upper mantle of the
Earth
How do plates move?
 Convection
of heat causes the
movement of lithospheric plates.
 Although plate movements do occur
because of when the Asthenosphere
heats there is enough Lithostatic pressure
to prevent it’s melting.
3 types of plate boundaries
 Convergent
boundaries
 Divergent boundaries
 Transform boundaries
Isostasy
 Equilibrium
in the Earth’s crust such that
the forces tending to elevate landmasses
balance the forces tending to depress
landmasses.
Isostatic adjustments
(Glacial Isostatic Adjustments)
 The
rise of land masses that
were depressed by the huge weight
of ice sheets during the last glacial period
 Via Isostasy
Stress
 A.K.A.
Tension. Refers to a stress which
stretches rocks in two opposite directions
 In relative it is also found in tectonic
regions of divergent boundaries
DIVERGENT
BOUNDARY
SEA-FLOOR SPREADING
A process that occurs at mid-ocean ridges, where
new oceanic crust is formed through volcanic
activity and then gradually moves away from the ridge.
For example a Mid-ocean ridge; The Juan de Fuca Ridge
is a tectonic spreading center off the coast of
Washington State. The Explorer Ridge
is a divergent tectonic plate boundary located about
241 km west of Vancouver Island, British
Columbia, Canada
PALEOMAGNETISM
The study of the record of the Earth's magnetic
field in rocks
Magnetic Reversals: Is the change in the
Earth’s magnetic field such that the positions
of magnetic north and magnetic south are
interchanged
Magnetic Symmetry: Puzzling magnetic
patterns in the sea-floor
NORMAL FAULTS
A normal fault occurs when the crust is
extended, can also be called an extensional
fault.
Wasatch Fault is an example of a normal fault
Sierra Nevada Fault is also an example of a
normal fault
Convergent
Plate
Boundary
Volcanoes
Magma
 A mixture of Molten Rock that is found beneath the
surface of the Earth
Conditions of Magma Formation
 An increase in temperature can cause materials in
the asthenosphere to melt. Such as the increase that
occurs at a hot-spot.
Lava
 Refers both to molten rock expelled by a volcano
during an eruption and the resulting rock after
solidification and cooling
Volcano
 An opening, or rupture, in a planet's surface or crust,
which allows hot magma, volcanic ash and gases to
escape from the magma chamber below the surface.
Common Locations
• Nazca Plate
• Eurasian Plate
• Pacific Ring of Fire*
• North American Plate
• Pacific Plate
• Arabian Plate
• *DENOTES MOST ACTIVE LOCATION FOR VOLCANOES
Major zone of Volcanoes in the Pacific
 Is called the Pacific “Ring of Fire”, where a large
number of Earthquakes and Volcanic eruptions in
the Pacific
 Horseshoe shape
 452 volcanoes in total and 90% of the World’s
earthquakes occur in the Pacific Ring of Fire
Pyroclastic Material
 Solid fragments of rock ejected during a volcanic
eruption
Viscosity of Pyroclastic Material
 It is likely to form at a high viscosity according to
history as studies on a volcano in Japan at Mount
Unzen show
How magma contents produce explosive eruptions
 Because felsic magma has a higher gas content than
mafic magma
Types of Volcanoes
 Shield
 Cinder Cone
 Composite
Shield volcano
 A type of volcano usually built almost entirely of
fluid lava flows.
 They are named for their large size and low visibility,
resembling a battle shield
 Ex: is Puʻu ʻŌʻō on Kīlauea, in Hawaii. Also the
Snake River in Idaho and the Columbia River in
Washington and Oregon
Cinder Cone volcano
 Cinder cone volcanoes are the most common kind of
volcanoes.
 They are steep sided cones of basaltic fragments and
are smaller and simpler than composite volcanoes.
 Streaming gases carry liquid lava blobs into the
atmosphere that fall back to earth around a single
vent to form the cone.
 Ex: Paricutin in Mexico and in Iceland, Surter I.
Composite Volcano
 A tall, conical volcano built up by many layers of
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hardened lava, pumice, and volcanic ash.
Unlike shield volcanoes, Composite volcanoes are
characterized by a steep profile and periodic explosive
eruptions and quiet eruptions.
The lava that flows from Composite volcanoes typically
cools and hardens before spreading far due to high
viscosity.
The magma forming this lava is (most of the time) felsic
Ex: Mount Fuji in Japan, Mount Tavurvur in Papau New
Guinea
Caldera
 Comes from the latin root word Caldaria, literally
means “cooking pot”, because of it’s positioning on
the volcano.
 Ex: Mount Fogo, Cape Verde. Off the coast of Africa.
Mount Pinatubo, Phillipines
Animated Representation of Calderas’
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The layer of igneous, sedimentary, and
metamorphic rocks which forms the
continents and the areas of shallow seabed
close to their shores
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Is the part of Earth's lithosphere that surfaces
in the ocean basins
Composed of Mafic rock
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Trenches and Undersea Mountains
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Normal Faults and Mid-ocean ridges
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A phenomenon of the plate
tectonics of Earth that occurs at convergent
boundaries where the subduction zone is
destroyed, mountains produced, and two
continents push together
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Uplift is a geological process often caused by
plate tectonics
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Folded Mountains, Plateaus, Dome Mountains.
Plateau: is an area of highland, usually consisting of
relatively flat terrain.
Folded Mountains: When one or a stack of originally flat
and planar surfaces, such as sedimentary, are bent or
curved as a result of permanent deformation
Dome Mountains: A deformational feature consisting of
symmetrically-dipping anticlines
Types of Folded Mountains: Anticline, Syncline, Antiform,
Synform, Dome, Basin, etc.
Types of Dome Mountains: Anticline, Basin, Granite
Dome, Petroleum Reservoir, Resurgent Dome, Salt Dome
Types of Plateaus: Tibetan Plateau, Antarctic Plateau,
Columbia Plateau. Are some of the most iconic
EARTHQUAKES
ELASTIC REBOUND
An explanation for how energy is spread
during earthquakes. As rocks on
opposite sides of a fault are subjected to
force and shift
SEISMOLOGY
 The scientific study of earthquakes and the propagation of
elastic waves through the Earth or through other planet-like
bodies
 Seismograph- Are instruments that measure motions in the
ground, including those of seismic waves generated by
earthquakes, volcanic eruptions, and other seismic sources.
FOCUS
The location within Earth along a fault at which the first motion of
an earthquake occurs
EPICENTER
 The point on the Earth’s surface that is directly above the
hypocenter or focus, the point where an earthquake originates
SEISMIC WAVES
 Waves of energy that travel through the Earth, and are a result of
an earthquake, explosion, or a volcano.
BODY WAVES
Waves that travel through Earth’s interior
TYPES OF BODY WAVES
P (Primary) waves- Compressional waves that travel
faster than any other waves through the earth, hence the
name “Primary”; Longitudinal
S (Secondary) waves- Shear waves that arrive at
seismograph stations after the faster moving P waves
during an earthquake; Transverse
SURFACE WAVES
 Seismic waves that travel along the surface of the Earth
TYPES OF SURFACE WAVES
 L(Love) waves- Named after A. E. H. Love, waves that travel
along the Earth's surface-travel slower than body waves-Because of
their low frequency, long duration, and large amplitude, they can be
the most destructive type of seismic wave
 Rayleigh Waves- Named after Lord Rayleigh, waves that travel
near the surface of solids. include both longitudinal and transverse
motions that decrease exponentially in amplitude as distance from the
surface increases
HOW SEISMIC WAVES LED
TO DETERMINATION OF
EARTH’S INTERIOR
 Seismic waves, which are generated naturally by
earthquakes, by volcanoes, and by impacts, and may be
produced artificially by explosions and mechanical devices, tell
us about the interior in several general ways.
 Firstly, Seismic waves have their direction of motion
changed by variations in the interior density.
EARTHQUAKES NOT
RESULTING FROM
MOVEMENT ALONG PLATE
BOUNDARIES
MAGNITUDE
 In correlation to Earthquakes, it is the measurement of the “size”
or amplitude of the seismic waves generated by an earthquake source
and recorded by seismographs.
INTENSITY
 A measure of the size of an earthquake based on observation of
the effects of the shock at the Earth's surface.
MERCALLI SCALE
 a seismic scale used for measuring the intensity of an earthquake,
it measures the effects of an earthquake.
 Example: The Earthquake in Haiti had a Mercalli Scale of 10
TSUNAMI
 Japanese Pseudonym, A long high sea wave caused by an
earthquake or other amphibious disturbance
 Example: The most prevalent (brought up in conversation) and
most recently was the devastating Tsunami that obliterated Japan back
in January of 2011 and also the Chilean Tsunami of 2010.
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A.K.A. extensional fault, occurs when the
crust is extended
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A fault surface that is usually near vertical and
the footwall moves either left or right or
laterally with very little vertical motion
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Refers to a stretch which stretches rocks in
two opposite directions
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Distortion of a body by pushing a body in
opposite directions
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http://maps.unomaha.edu/maher/plate/week3/contrift.ht
ml
http://en.wikipedia.org/wiki/Panthalassa
http://en.wikipedia.org/wiki/Pangaea
www.Google.com
www.thefreedictionary.com
http://en.wikipedia.org/wiki/Tectonic_uplift
http://en.wikipedia.org/wiki/Explorer_Ridge
http://en.wikipedia.org/wiki/Juan_de_Fuca_Plate
http://en.wikipedia.org/wiki/Augustus_Edward_Hough_
Love
http://wiki.answers.com/Q/How_are_seismic_waves_use
d_to_provide_evidence_about_Earth%27s_interior
www.tulane.edu/~sanelson/eens1110/volcanoes.htm