Unit 3: Geology

1
Unit 3 Geology
2
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

3
A. Mapping the World

• Latitude and Longitude
• Time Zones

4
B. Geologic Time

• Geologic Time Scale
• The Rock Record

5
C. Composition of the Earth

• Matter and Atomic Structure
• Minerals
• Igneous Rocks
• Sedimentary Rocks
• Metamorphic Rocks
• Anatomy of Earth

6
D. Plate Tectonics

• Continental Drift
• Seafloor Spreading
• Theory of Plate Tectonics

7
E. Volcanoes

• Magma
• Intrusive Activity
• Volcanoes

8
F. Earthquakes

• Forces within Earth
• Seismic Waves
• Measuring Earthquakes
• Earthquakes and Society

9
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

10
A. Mapping the World

• Latitude and Longitude
• Cartography
• The science of map making
• Cartos Map (Greek), -graphy to draw

11
Latitude is

• Imaginary lines running parallel to the equator
• The distance in degrees north and south of the
  equator
• The equator is the reference point for all lines
  of latitude and is defined as 0 latitude.

12
Longitude is

• Imaginary lines that locate positions in east and
  west directions.
• The distance in degrees east or west of the Prime
  Meridian, which is the reference point for
  longitude.
• The prime meridian represents 0 longitude.

13
Degrees of Latitude

• Each degree of latitude is approximately 111
  kilometers (50 miles) on Earths surface.
• Question 1
• How many miles is 22 of latitude?
• Question 2
• If you travel 800 miles south of the equator
  right along the Prime Meridian, what exactly are
  your coordinates?

14
Degrees of Latitude

• Question 3
• If you travel from 33N, 104W to 30S, 104W, in
  which direction are you traveling?
• Question 4
• What are the coordinates for the following 3
  major cities Sydney, New York, and Mexico City?

15
Anatomy of the World
North Pole (90N)
Tropic of Cancer (23.5N)
Equator (0)
Tropic of Capricorn (23.5S)
South Pole (90S)
16
2. Time Zones

17
Time Zones in the U.S.

• Wide countries are often split into multiple time
  zones.
• The U.S. has six time zones including Alaska and
  Hawaii

18
(No Transcript)
19
Time Zone Fact

• Every time zone is roughly 15 wide.

20
Time Zones

• Question 5
• If it is 5 pm on Friday, June 21, in Madagascar,
  Africa, what time and day is it in Juneau,
  Alaska?
• Question 6
• Suppose city X is 75 west of city Y. When it is
  1100 P.M. in city X, what time is it likely to
  be in city Y?

21
Juneau
13 hour difference
Madagascar500 PM
22
Time Zones

• Question 7
• Why is it that time zones are affected by
  longitude and not by latitude?

23
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

24
B. Geologic Time

• Geologic Time Scale
• The Rock Record

25
1. Geologic Time Scale

• At the bottom of the Grand Canyon there are rocks
  dating back 400 million years or more!
• These rocks record the rich and old history of
  the earth.

26
1. Geologic Time Scale
Youngest rock
Oldest rock
27
Geologic Time Scale

• The age of the planet
• How old is planet Earth?
• Approximately 4.6 billion years old

28
Putting it in perspective

• A lot of history has taken place in the last 225
  years in the U.S.
• Signing of the Declaration of Independence
• Louisiana Purchase
• Industrial Revolution
• The Civil War
• Invention of the electric light bulb
• Stock Market Crash
• Neil Armstrongs walk on the moon
• And many events more!

29
Putting it in perspective

• So the question is
• How does 225 years compare with 4.6 billion
  years?
• If 4.6 billion years were equivalent to 100 yards
  (length of a football field), then

30
Putting it in perspective

• 225 years would be 1/100 of a inch!

31
2. The Rock Record

• By studying the rock record, scientists can
• Interpret the environment in which rocks
  deposited
• Reconstruct the Earths history
• Predict events or conditions in the future

32
How do we know the age of rocks?

• By using Carbon-dating techniques
• http//www.c14dating.com/int.html

33
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

34
C. Composition of the Earth

• Matter and Atomic Structure
• Minerals
• Igneous Rocks
• Sedimentary Rocks
• Metamorphic Rocks
• Anatomy of Earth

35
1. Matter and Atomic Structure
36
What are elements?

• All matter is made of elements
• Element a substance that cannot be broken down
  into simpler substances by physical or chemical
  means.

37
What are elements?

• Elements can be found in the Periodic Table
• The periodic table was invented by Russian
  scientist Dimitri Mendeleev in 1865

38
Dimitri Mendeleev
39
What are elements?

• Anything and everything on planet Earth can be
  found in the periodic table of elements!

40
What are elements?

• Hydrogen is the first element in the periodic
  table
• Hydrogen is an ATOM

41
What are elements?
Atomic number
Name
Symbol
Atomic mass
42
What are the most abundant elements?

• On Earth
• Oxygen (47)
• Silicon (28)
• Aluminum (8)
• Iron (5)
• Calcium (4)

• In the universe
• Hydrogen (94)
• Helium (5)
• 8 others (1)

43
What are atoms?

• Elements are made of atoms
• Atom the smallest particle of an element
• Atoms can be broken down into smaller particles!

44
Parts of an Atom
45
(No Transcript)
46
Parts of an Atom

• Atomic Number
• The of protons in the nucleus of an atom
• The of electrons in the nucleus also
• Atomic Mass
• The number of protons neutrons

47
So what does an atom look like?
Nucleus (p and n0)
Electrons
48
Homework assignment

• Pick any 3 elements from the periodic table of
  elements found on page 36-37 in your text.
• For each element, provide the following
• Draw the element box (name and symbol)
• Atomic mass
• Atomic number
• of electrons
• of protons
• of neutrons
• Draw a picture of the element (any format)

49
Mr. Ss element
Sulfur
50
Element Card

• Pick an element
• Draw the following
• Element name
• Element symbol
• Atomic
• Atomic mass

• Log on
• www.chemicalelements.com
• Include the following in your card
• Date of discovery and person who discovered it.
• 8 characteristics about the element.
• Is it a solid, liquid, or gas?

51
Atomic Structure
52
The Molecular Theory

• All matter is made up of molecules.
• Molecules are constantly moving.
• There is space between molecules.

53
The 4 States of Matter

• All matter exists in 4 states
• Solids
• Liquids
• Gases
• Plasma

54
Plasma

• When matter is heated to temperatures greater
  than 5000C, the collisions between particles are
  so violent that electrons are knocked away from
  atoms. Such extreme high temperatures exist in
  stars. These conditions are known as plasma.

55
Did you know?

• Water is the only substance that exists in nature
  in all 3 states of matter!

56
Solids

• Solids have definite shape
• Solids have definite volume

57
Liquids

• Liquids have definite volume
• Liquids have indefinite shape

58
Gases

• Gases have indefinite shapes
• Gases have indefinite volumes

59
Changing Phases of Matter
60
Deposition
Freezing
Condensation
LIQUID
SOLID
GAS
Melting
Evaporation
Sublimation

• Add energy
• Remove energy

61
2. Minerals
62
What is a mineral?

• A mineral is
• A naturally occurring, inorganic solid with a
  specific chemical composition and a definite
  crystalline structure.

63
Facts about minerals

• Earth is composed of about 3000 minerals.
• Calcite is the mineral that forms the 2 million
  limestone blocks in the Great Pyramid of Egypt.

64
(No Transcript)
65
Elements in the Earths Crust
66
The most abundant mineral!

• Silicates
• Oxygen is the most abundant element followed by
  Silicon
• O Si ? SiO2 (silicate)
• Silicates make up 96 of the minerals found in
  Earths crust!

67
Identifying Minerals
68
Identifying Minerals

• Geologists rely on several simple tests to
  identify minerals
• These tests are based upon the minerals physical
  and chemical properties.

69
Identifying Minerals

• Minerals can be identified using 5
  characteristics
• Color
• Luster
• Texture
• Streak
• Hardness

70
Color

• Color is caused by the presence of elements or
  compounds within a mineral.
• This is one of the least reliable clues to a
  minerals identity.

71
Luster

• Luster is the way a mineral reflects light from
  its surface.

72
Texture

• Texture describes how a mineral feels to the
  touch.
• Texture can be described as
• Smooth, Rough, Ragged, Greasy, Soapy, or Glassy

73
Streak

• Streak is the color of a mineral when it is
  broken up and powdered.

74
Hardness

• Hardness is a measure of how easily a mineral can
  be scratched.
• This is one of the most useful ways to identify
  minerals.

75
Hardness

• German geologist Friedrich Mohs developed a scale
  in which an unknown minerals hardness can be
  compared to the hardness of ten known minerals.
  This scale is known as the Mohs Hardness Scale.

76
Friedrich Mohs
77
(No Transcript)
78
Mineral Uses

• Right now you are probably sitting on minerals,
  wearing minerals, and perhaps even eating
  minerals.
• Minerals are virtually everywhere!
• They are used to make computers, cars, t.v.s,
  desks, roads, buildings, jewelry, paints,
  medicines, etc.

79
The Price of Diamonds(Gemstones, p.56-57 in your
text!)

• The cost of a diamond depends on four things,
  often called the 4 Cs
• Color
• Cut
• Clarity
• Carat weight

80
Rock Types

• There are 3 types of rocks
• Igneous
• Sedimentary
• Metamorphic

81
3. Igneous Rocks

• Igneous rocks are formed from the crystallization
  of magma.

82
Igneous Rocks

• The term igneous comes from the Latin word ignis,
  which means fire.
• Because early geologists associated igneous rocks
  with fiery lava flows.

83
What is Lava?
84
What is Lava?

• Lava is magma that flows out onto Earths
  surface.
• Mix of molten rock, gases, and minerals.
• Made up of oxygen (O), silicon (Si), aluminum
  (Al), Iron (Fe), Magnesium (Mg), calcium (Ca),
  potassium (K), and sodium (Na)

85
What is Lava?

• Of all the compounds found in magma, silica
  (SiO2) is the most abundant.

86
Origins of Magma

• Most rocks melt between 800C and 1200C
  depending on their composition.
• In nature these temperatures are found in the
  upper mantle and lower crust.
• Factors that affect magma formation include
  temperature and pressure.

87
4. Sedimentary Rocks

• When sediments on the surface of the earth get
  really compacted, sedimentary rocks form.

88
Sedimentary Rocks

• What are sediments?
• Pieces of solid material that have been deposited
  on Earths surface by
• Wind
• Water
• Ice
• Gravity
• Chemical precipitation

89
Sedimentary Rocks

• When sediments get cemented together, they form
  sedimentary rocks.

90
Sedimentary Rocks
Sediments
Sedimentary rocks
91
How do sediments turn into rock?
Sediments
Settled particles
DEPOSITION
BURIAL
Particles buried by pressure
LITHIFICATION
Sedimentary rocks
Lithos Rock (Greek)
92
5. Metamorphic Rocks

• When rocks are buried at even greater
  temperatures, they undergo metamorphosis

93
Metamorphic Rocks

• Pressure and temperature increase with depth on
  Earth
• Question What happens to sedimentary rocks
  when they are heated but do not quite melt?
• Answer They form metamorphic rocks

94
The Rock Cycle
Sediments
Deposition
Burial
Weathering and erosion
Lithification
SEDIMENTARY
Earth Surface
IGNEOUS
Heat and Pressure
Cooling and Crystallization
METAMORPHIC
Melting
Magma
95
6. Anatomy of Earth
96
Anatomy of Earth
20 miles deep Rocky, brittle Ca, Na, Al, Si02 32F
2,000 miles deep Solid (plastic) Mg, Fe, Al,
SiO2 2,000F
Crust
Mantle
Core
Solid Fe 8,500F
800 miles deep Liquid Fe, S 7,000F
Inner core
97
Rock Cycle Project (30 pts.)

• You must have the following
• All the steps of the rock cycle (flow chart)
• With brief description of each step
• Ex Weathering is a process in which wind,
  water, and ice cause the erosion of a rock.
• 1 sample of each rock type
• If cant find one, find a picture online
• Anything else you want to make your presentation
  colorful, and different ?

98
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

99
D. Plate Tectonics

• Continental Drift
• Seafloor Spreading
• Theory of Plate Tectonics

100
1. Continental Drift

• What is continental drift?
• Is a theory that proposes that Earths continents
  had once been joined as a single landmass.
• This landmass was called PANGAEA by German
  geologist Alfred Wegener in 1912.

101
Alfred Wegener
102
Pangaea
103
225 mya
200 mya
150 mya
65 mya
Present
104
2. Seafloor Spreading

• Until the mid-1900s, most scientists thought
  that the ocean floor was flat.
• The advance of technology allowed scientists to
  prove this idea wrong!

105
Seafloor Spreading

• What technological advances allowed scientists to
  explore the sea floor?
• Magnetometer
• Paleomagnetism
• Sonar

106
Magnetometer

• A device that can detect small changes in
  magnetic fields.
• The readings are used to make magnetic maps of
  the ocean floor.

107
Paleomagnetism

• Rocks contain iron-bearing minerals and therefore
  have magnetic properties.
• Paleomagnetism is the study of the Earths
  magnetic field.

108
Sonar

• These are echo-sounding methods.
• Sonar uses sound waves to measure water depth.

109
Seafloor Spreading

• Once scientists compiled all the topographic,
  sedimentary, age, and magnetic data from the
  seafloor, an American scientist named Harry Hess
  proposed the theory of seafloor spreading.

110
Harry Hess
111
Seafloor Spreading Theory

• The theory says that
• New ocean crust is formed at ocean ridges and
  destroyed at deep-sea trenches.

112

• What happens during seafloor spreading?
• Magma, because it is hotter and less dense than
  surrounding mantle material, is forced toward the
  crust along an ocean ridge and fills the gap that
  is created. When magma cools, it hardens and
  forms new ocean floor on the surface of the
  earth.

113
(No Transcript)
114
3. Theory of Plate Tectonics

• Do you know why earthquakes occur more frequently
  in some areas than in others?

115
Theory of Plate Tectonics

• The theory states that
• Earths crust and rigid upper mantle are broken
  up into enormous slabs called plates

116
Theory of Plate Tectonics
117
(No Transcript)
118
(No Transcript)
119
(No Transcript)
120
Plate Tectonics

• Where tectonic plates interact it is called plate
  boundaries.
• At some boundaries, plates can either converge,
  diverge, or move horizontally past one another
  (transform).

121
Convergent Plates
122
Divergent Plates
123
Transform Plates
124
(No Transcript)
125
Causes of Plate Motions

• What causes the tectonic plates to move?
• Mantle convection

126
Mantle Convection
127
(No Transcript)
128
(No Transcript)
129
Mantle ConvectionDEMO
Bunsen burner
Food coloring
Ice
Beaker
130
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

131
E. Volcanoes

• Magma
• Intrusive Activity
• Volcanoes

132
1. Magma

• There are 3 types of magma
• Basaltic magma
• When rocks in upper mantle melt, little viscosity
• Volcanoes erupt quietly
• Andesitic magma
• Composed of oceanic crust or oceanic sediments
• 60 silica
• Intermediate eruptions
• Rhyolithic magma
• Very viscous
• Violent, explosive eruptions

133
(No Transcript)
134
(No Transcript)
135
2. Intrusive Activity

• Uprising magma can affect the crust in several
  ways by intruding into it.

136
3. Volcanoes

• Volcanoes produce various features that alter
  Earths landscape.
• There are thousands of volcanoes on Earth, many
  are still active today.

137
Worlds Active Volcanoes
Mt. Shasta (41N, 122W)
Fuji (35N, 139E)
Colima (19N, 104W)
Kilimanjaro (3S, 37E)
Copahue (38S, 71W)
138
(No Transcript)
139
(No Transcript)
140
(No Transcript)
141
(No Transcript)
142
(No Transcript)
143
(No Transcript)
144
(No Transcript)
145
(No Transcript)
146
(No Transcript)
147
(No Transcript)
148
(No Transcript)
149
Anatomy of a Volcano

• Regardless of the type, all volcanoes have the
  following characteristics in common
• Vent
• At the surface of Earth, where lava erupts.
• Crater
• Bowl-shaped depression around the vent.
• Volcanic craters are usually less than ½ mile in
  diameter. Larger craters are called calderas.
• Magma Chamber
• Crater connected to magma chamber by the vent.

150
Types of Volcanoes

• There are 3 types of volcanoes
• Shield volcano
• Cinder-Cone volcano
• Composite volcano

151
Shield Volcano

• Broad slopes
• Nearly circular base
• They form when layer upon layer of basaltic lava
  accumulates during non-explosive eruptions.

152
(No Transcript)
153
Cinder-Cone Volcano

• Lava gets ejected high into the air and falls
  back and piles up around the vent
• Steep slopes
• Very explosive
• Generally small (500 meters high)

154
(No Transcript)
155
Composite Volcano

• Forms when layers of volcanic fragments alternate
  with lava
• Much larger than cinder-cone
• Violent explosions

156
(No Transcript)
157
Composite
158
Cinder-Cone
159
Shield
160
Volcano Project (30 pts.)

• Make a model of a volcano and include the
  following
• Volcano anatomy
• Vent, crater, magma chamber
• Volcano type
• Composite, shield, cinder-cone
• Magma type
• Basaltic, andesitic, rhyolithic
• Must show the inside of the volcano
  (cross-section)
• Volcano must erupt!

161
Materials you can use for volcano
162
Unit 3 Geology

• Mapping the World
• Geologic Time
• Composition of the Earth
• Plate Tectonics
• Volcanoes
• Earthquakes

163
Welcome Back!!!
164
F. Earthquakes

• Forces within Earth
• Seismic Waves
• Measuring Earthquakes
• Earthquakes and Society

165
(No Transcript)
166
(No Transcript)
167
(No Transcript)
168
(No Transcript)
169
(No Transcript)
170
(No Transcript)
171
(No Transcript)
172
Jan. 17, 1994 Northridge
173
1. Forces within the Earth

• Most earthquakes occur when rocks fracture, or
  break up, deep beneath the earths surface.
• Fractures form when there is too much stress in
  the rock.

174
Forces within the Earth

• STRESS
• There are 3 kinds of stress that act on Earth's
  rocks
• Compression
• Tension
• Shear

175
Forces within the Earth

• Compression Stress that decreases the volume of
  a material.

176
Forces within the Earth

• Tension Stress that pulls a material apart.

177
Forces within the Earth

• Shear Stress that causes a material to twist.

178
(No Transcript)
179
(No Transcript)
180
(No Transcript)
181
(No Transcript)
182
(No Transcript)
183
2. Seismic Waves

• The study of earthquake waves is called
  seismology.

184
Seismic Waves

• Seismic waves can be detected and recorded by
  sensitive instruments called seismometers.

185
Seismometer
186
Seismic Waves

• Seismic waves provide knowledge of Earths
  interior.
• Seismic waves change direction and speed when
  they encounter different materials.

187
Seismic Waves

• There are 2 types of seismic waves
• Body waves
• P-waves
• Flow in direct paths.
• Are refracted, or bent, when they strike the
  core.
• S-waves
• They cannot travel through liquids.
• Surface waves
• Travel along earths surface.

188
(No Transcript)
189
3. Measuring Earthquakes

• There are more than 1 million earthquakes in the
  world per year!
• 90 of these are not felt and cause little damage.

190
Measuring Earthquakes

• The amount of energy released during an
  earthquake is measured by its magnitude.
• Magnitude uses Richter Scale values.

191
Charles Richter
192
Measuring Earthquakes

• The Richter Scale
• An earthquakes rating on the Richter scale is
  based on the size of the largest seismic wave
  generated by the quake.
• Each number in the scale represents an increase
  in seismic-wave size, or amplitude, of a factor
  of 10.

193
Measuring Earthquakes

• Question
• What is the difference in magnitude between an
  earthquake that is a 6.0 in the Richter versus an
  earthquake that is 7.0?
• What about two earthquakes with magnitudes 7.0
  and 9.0?

194
Measuring Earthquakes

• Another way to assess earthquakes is to measure
  the amount of damage done to the structures
  involved.
• This measure, called intensity of an earthquake,
  is determined using the Mercalli Scale.

195
Giuseppe Mercalli
196
(No Transcript)
197
Measuring Earthquakes

• Examine the next 5 scenarios and give to each a
  Mercalli value

198
(No Transcript)
199
(No Transcript)
200
 
201
(No Transcript)
202
(No Transcript)
203
4. Earthquakes and Society

• What types of damage are caused by earthquakes?
• What kinds of factors affect the damage done
  during an earthquake?
• Is it possible to predict earthquakes?

204
Earthquakes and Society

• Some earthquake hazards are
• Land and soil failure
• Fault scarps
• Tsunami

205
Earthquakes and Society

• Land and soil failure can produce
• Massive landslides
• Trees and houses fall over
• Underground pipes and tanks rise to the surface

206
Earthquakes and Society

• Fault scarps are produced when a fault line
  intercepts the ground surface.

207
Earthquakes and Society

• A tsunami is a large ocean wave generated by
  vertical motions of the seafloor during an
  earthquake.

208
(No Transcript)
209
(No Transcript)
210
(No Transcript)
211
(No Transcript)
212
(No Transcript)
213
(No Transcript)
214
(No Transcript)
215
(No Transcript)
216
(No Transcript)
217
(No Transcript)
218
South East Asia Earthquake December 26, 2004
219
(No Transcript)
220
(No Transcript)
221
(No Transcript)
222
(No Transcript)
223
(No Transcript)
224
(No Transcript)
225
Before
226
After
227
(No Transcript)
228
(No Transcript)
229
Earthquakes and Society
230
(No Transcript)
231
(No Transcript)
232
SAN ANDREAS FAULT
Pacific Plate
North American Plate