6. How do we date rocks?
–Relative time
• Superpostion
4
7. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
4
8. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
4
9. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
• Radiometric dating
4
10. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
• Radiometric dating
–Atoms with unstable nuclei (isotopes) decay into
stable forms
4
11. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
• Radiometric dating
–Atoms with unstable nuclei (isotopes) decay into
stable forms
–Each isotope has a specific decay rate
4
12. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
• Radiometric dating
–Atoms with unstable nuclei (isotopes) decay into
stable forms
–Each isotope has a specific decay rate
–Half-life--the length of time it takes one half the isotope to
decay
4
13. How do we date rocks?
–Relative time
• Superpostion
–Oldest rocks on the bottom, youngest rocks on the top
–Absolute time
• Radiometric dating
–Atoms with unstable nuclei (isotopes) decay into
stable forms
–Each isotope has a specific decay rate
–Half-life--the length of time it takes one half the isotope to
decay
–Measuring the ratio of unstable to stable material
gives a date (1:1 means one half-life has passed)
4
15. The oldest rocks
Earth
first condensed and formed into a
planet about 4.6 billion years ago.
5
16. The oldest rocks
Earth first condensed and formed into a
planet about 4.6 billion years ago.
Oldest rocks are from the Acasta Gneiss
in northwestern Canada: 3.96 billion
years old
5
17. The oldest rocks
Earth first condensed and formed into a
planet about 4.6 billion years ago.
Oldest rocks are from the Acasta Gneiss
in northwestern Canada: 3.96 billion
years old
Oldest grains of rock, from Western
Australia: bet. 4.2 and 4.4 billion years
old
5
19. Uniformitarianism
• Uniformitarianism
–“The present is the key to the past.”
–In other words: The same physical processes
active in the environment today have been
operating throughout geologic time.
21. Earth’s magnetic field
• Circulations within Earth’s inner and outer
cores may be the mechanism for the
magnetic field, called the magnetosphere,
that protects Earth from solar wind and
cosmic radiation.
8
22. Earth’s magnetic field
• Circulations within Earth’s inner and outer
cores may be the mechanism for the
magnetic field, called the magnetosphere,
that protects Earth from solar wind and
cosmic radiation.
• The magnetic north and south poles migrate
8
23. Earth’s magnetic field
• Circulations within Earth’s inner and outer
cores may be the mechanism for the
magnetic field, called the magnetosphere,
that protects Earth from solar wind and
cosmic radiation.
• The magnetic north and south poles migrate
• Geomagnetic reversal also happens in
irregular intervals
8
25. Which elements make up
Earth’s crust?
• Core
–Fe, Ni, Si (and/or) O
• Mantle
–O, Si, Mg, Fe, Ca, Al
• 99% of the crust is made up of 8 elements:
–O, Si (make up 74.3%)
–Al, Fe, Ca, Na, K, Mg
These elements, and trace others, combine to
make up Earth’s minerals and rocks...
10
28. What is a Mineral?
A mineral is…
a naturally-occurring,
29. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
30. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
with a definite
31. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
with a definite
(but generally not fixed)
32. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
with a definite
(but generally not fixed)
chemical composition
33. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
with a definite
(but generally not fixed)
chemical composition
and a highly-ordered
atomic arrangement.
34. What is a Mineral?
A mineral is…
a naturally-occurring,
homogeneous solid
with a definite
(but generally not fixed)
chemical composition
and a highly-ordered
atomic arrangement.
It is usually formed through
inorganic processes.
46. ...homogeneous solid...
• It can’t start out as one mineral and become
another mineral halfway through (but it can
change color and still be the same mineral)
47. ...homogeneous solid...
• It can’t start out as one mineral and become
another mineral halfway through (but it can
change color and still be the same mineral)
Tourmaline (Elbaite variety):
Na(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)4
51. ...definite (but generally not fixed)
chemical composition...
• Quartz
–SiO2 (silicon dioxide)
• Olivine
52. ...definite (but generally not fixed)
chemical composition...
• Quartz
–SiO2 (silicon dioxide)
• Olivine
–(Mg, Fe)2SiO4
53. ...highly-ordered atomic
arrangement.
• Carbon dioxide gas is made up of atoms that
are not all bonded together into a structure.
54. ...highly-ordered atomic
arrangement.
• Carbon dioxide gas is made up of atoms that
are not all bonded together into a structure.
• When frozen, CO2 IS bonded together...
forming...what?
55. ...highly-ordered atomic
arrangement.
• Carbon dioxide gas is made up of atoms that
are not all bonded together into a structure.
• When frozen, CO2 IS bonded together...
forming...what?
56. ...highly-ordered atomic
arrangement.
• Carbon dioxide gas is made up of atoms that
are not all bonded together into a structure.
• When frozen, CO2 IS bonded together...
forming...what?
57. The shape of the mineral crystal is the result of
its internal atomic structure.
rhombohedrons
flat sheets muscovite mica
chains
cubes
rhodochrosite
asbestos (crocidolite) galena
58. What if a substance doesn’t fit the
whole definition?
59. What if a substance doesn’t fit the
whole definition?
• It’s a mineraloid.
60. What if a substance doesn’t fit the
whole definition?
• It’s a mineraloid.
Some substances look like minerals--but they LIE.
61. What if a substance doesn’t fit the
whole definition?
• It’s a mineraloid.
Some substances look like minerals--but they LIE.
• Glass is a mineraloid. It has an “amorphous” atomic
structure.
62. What if a substance doesn’t fit the
whole definition?
• It’s a mineraloid.
Some substances look like minerals--but they LIE.
• Glass is a mineraloid. It has an “amorphous” atomic
structure.
-O
- Si
63.
64. As light passes through the glass panels, it is distorted
by the ripples in the glass. Which panel is the new one?
67. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
68. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
69. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
70. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
71. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
72. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
73. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
74. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
75. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
• Silicate minerals
76. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
• Silicate minerals
• Their skeletons are used as polishing
agents...
77. Biogenic minerals: Exceptions to
the “inorganic processes” rule
Formed by living things
– The pearl and shells of oysters
• Aragonite
– The main mineral found in human
bones and teeth
• Apatite
– Diatoms and radiolarians in the
ocean
• Silicate minerals
• Their skeletons are used as polishing
agents...
...(in your toothpaste!)
83. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
84. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
–They have no definite chemical composition
85. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
–They have no definite chemical composition
–They have no ordered atomic arrangement
86. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
–They have no definite chemical composition
–They have no ordered atomic arrangement
Petroleum, coal and peat are mineraloids
87. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
–They have no definite chemical composition
–They have no ordered atomic arrangement
Petroleum, coal and peat are mineraloids
But…They can form minerals under certain conditions
88. Is coal a mineral?
No.
Coal, petroleum, and peat are NOT minerals.
–They have no definite chemical composition
–They have no ordered atomic arrangement
Petroleum, coal and peat are mineraloids
But…They can form minerals under certain conditions
–If coal beds are heated to high temperatures and the
carbon in them is crystallized, they can form the mineral,
graphite
91. Mineral Formation:
Non-organic formation
• Minerals can form from:
–Magma
92. Mineral Formation:
Non-organic formation
• Minerals can form from:
–Magma
–Steam (these minerals are called vaporites)
93. Mineral Formation:
Non-organic formation
• Minerals can form from:
–Magma
–Steam (these minerals are called vaporites)
–Mineral components left behind when water
evaporates (these are called evaporites)
94. Mineral Formation:
Non-organic formation
• Minerals can form from:
–Magma
–Steam (these minerals are called vaporites)
–Mineral components left behind when water
evaporates (these are called evaporites)
–Mineral components dissolved in water that solidify
again (these are called precipitates)
95. From cooled magma
• The mineral components come together in the
melt and harden as molten rock material
solidifies
98. From steam: vaporites
• Vaporite
–Water near a magma source heats up, dissolves
mineral components in surrounding rocks, and
carries them away
99. From steam: vaporites
• Vaporite
–Water near a magma source heats up, dissolves
mineral components in surrounding rocks, and
carries them away
–The steam condenses at the surface. The mineral
compounds also “condense” and solidify.
100. From steam: vaporites
• Vaporite
–Water near a magma source heats up, dissolves
mineral components in surrounding rocks, and
carries them away
–The steam condenses at the surface. The mineral
compounds also “condense” and solidify.
101. From steam: vaporites
• Vaporite
Harvesting sulfur crystals from a volcano in Indonesia
–Water near a magma source heats up, dissolves
mineral components in surrounding rocks, and
carries them away
–The steam condenses at the surface. The mineral
compounds also “condense” and solidify.
–Commonly found around
volcanic vents, these sulfur
crystals are forming around
Kilauea Crater, Hawaii. Also
found near oceanic volcanic
vents (at spreading centers).
105. From evaporating water: evaporites
• Evaporite
–Water evaporates, but leaves behind any mineral
compounds that were dissolved in the water
106. From evaporating water: evaporites
• Evaporite
–Water evaporates, but leaves behind any mineral
compounds that were dissolved in the water
107. From evaporating water: evaporites
• Evaporite
–Water evaporates, but leaves behind any mineral
compounds that were dissolved in the water
–Hint: “Please pass the halite!”
108. From evaporating water: evaporites
• Evaporite
–Water evaporates, but leaves behind any mineral
compounds that were dissolved in the water
–Hint: “Please pass the halite!”
Salt crystals like these form in
salt beds along the edge of
Highway 84, just before the
Dumbarton Bridge.
111. Mineral Formation:
Non-organic formation
• Precipitate
–When in too high a concentration to remain
dissolved in a liquid, the mineral components
condense and may actually “rain” out of the
solution
112. Mineral Formation:
Non-organic formation
• Precipitate
–When in too high a concentration to remain
dissolved in a liquid, the mineral components
condense and may actually “rain” out of the
solution
–Often occurs when warmer water, which can
hold more dissolved solids, cools slightly
113. From dissolved solids: precipitates
Oolitic beach sand from the Caribbean, the Bahamas,
and Great Salt Lake in Utah form from calcium
carbonate precipitating out of the water
114. From dissolved solids: precipitates
Oolitic beach sand from the Caribbean, the Bahamas,
and Great Salt Lake in Utah form from calcium
carbonate precipitating out of the water
115. From dissolved solids: precipitates
Oolitic beach sand from the Caribbean, the Bahamas,
and Great Salt Lake in Utah form from calcium
carbonate precipitating out of the water
116. From dissolved solids: precipitates
Oolitic beach sand from the Caribbean, the Bahamas,
and Great Salt Lake in Utah form from calcium
carbonate precipitating out of the water
117. From dissolved solids: precipitates
Pyrite “sand dollars” form in sea water and collect on the
ocean floor
122. What is a Rock?
• A solid, cohesive aggregate of one or
more minerals or mineral materials
–A few rock varieties are made up almost
entirely of one mineral—this is called a
pegmatite
123. What is a Rock?
• A solid, cohesive aggregate of one or
more minerals or mineral materials
–A few rock varieties are made up almost
entirely of one mineral—this is called a
pegmatite
• Example: massive accumulations of halite
124. The Rock Cycle
• Rocks have been continuously forming and
reforming over millions and millions of years
• The rock cycle is a closed flow system
128. What drives the rock cycle?
• Earth’s internal heat
–Radioactive decay from its initial formation
129. What drives the rock cycle?
• Earth’s internal heat
–Radioactive decay from its initial formation
• the power source for the flow system
130. What drives the rock cycle?
• Earth’s internal heat
–Radioactive decay from its initial formation
• the power source for the flow system
• The sun
131. What drives the rock cycle?
• Earth’s internal heat
–Radioactive decay from its initial formation
• the power source for the flow system
• The sun
–Secondary power source
132. What drives the rock cycle?
• Earth’s internal heat
–Radioactive decay from its initial formation
• the power source for the flow system
• The sun
–Secondary power source
–Drives weather systems that erode material
136. Convection Currents
• Slow-moving convection
currents within the mantle
transfer heat from the outer
core to the upper mantle
• The convergence and
divergence of these currents
near the surface is believed to
be one of the driving forces
behind the movement of
Earth’s crustal plates
138. The 3 Classes of Rock
• Classified based on the processes which
form them
139. The 3 Classes of Rock
• Classified based on the processes which
form them
–Igneous rocks
140. The 3 Classes of Rock
• Classified based on the processes which
form them
–Igneous rocks
–Sedimentary rocks
141. The 3 Classes of Rock
• Classified based on the processes which
form them
–Igneous rocks
–Sedimentary rocks
–Metamorphic rocks
142. Igneous Rocks
from cooling magmas
• The kinds of rocks you end up with (and
ultimately the kinds of structures built by the
formation of those rocks) are determined by
the chemistry of the magmas you start with
144. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
145. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
146. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
147. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
148. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
149. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
• Highly viscous (resistant to flow)
150. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
• Highly viscous (resistant to flow)
• High concentration of gases under high pressure
151. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
• Highly viscous (resistant to flow)
• High concentration of gases under high pressure
• Gases can’t rise easily, so they stay trapped until near
the surface
152. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
• Highly viscous (resistant to flow)
• High concentration of gases under high pressure
• Gases can’t rise easily, so they stay trapped until near
the surface
• As pressure is released at the surface, these
pressurized gases tend to explode
153. Felsic Magmas
• The “fel” is for feldspar (made from Si, Al, O), “si” is for
silicates (made from Si and O)
• Lighter in color, lower in density than mafic minerals
• Continental crust is predominantly felsic material
• Cooler magmas, containing lots of silica (SiO2)
• Highly viscous (resistant to flow)
• High concentration of gases under high pressure
• Gases can’t rise easily, so they stay trapped until near
the surface
• As pressure is released at the surface, these
pressurized gases tend to explode
– (Example: Mount St. Helens)
154. Mount Saint Helens
• The explosion blew off 1,300 feet of the mountain's top
and sent ash and debris more than 12 miles into the sky
covering three states - Washington, Oregon, and Idaho.
Sixty two people were dead, beautiful forests and lakes
were destroyed resulting in $3 billion worth of damage.
• ‘[At about 10:00 a.m.] in the city of Yakima, Washington…
a black cloud covered the city and "snowed" ash. [Not] a
street light nor a neighbor's porch light could be seen. The
ash was so heavy it sank swimming pool covers and
caved in old roofs. Businesses and schools were closed
down and all normal activity… ceased to exist.”
From Disasters: Blowing Your Top http://www.boisestate.edu/history/
ncasner/hy210/volcano.htm
159. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
160. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
161. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
• Oceanic crust is predominantly mafic
162. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
• Oceanic crust is predominantly mafic
• Low viscosity (flow easily for long distances)
163. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
• Oceanic crust is predominantly mafic
• Low viscosity (flow easily for long distances)
• Very little gas content, relatively little SiO2
164. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
• Oceanic crust is predominantly mafic
• Low viscosity (flow easily for long distances)
• Very little gas content, relatively little SiO2
• Hotter magmas, so gasses stay dissolved
165. Mafic Minerals and Rocks
• The “ma” is for magnesium, the “f” for iron
(Fe--ferris); contains more metallic, heavy
elements (Al, Mg, Fe, K, Ca)
• Darker in color, higher in density
• Oceanic crust is predominantly mafic
• Low viscosity (flow easily for long distances)
• Very little gas content, relatively little SiO2
• Hotter magmas, so gasses stay dissolved
• Rarely explosive
– (Example: Hawaiian volcanoes)
166. Mafic Magmas
Hawaii
2002-10-11 view northwest across coastal plain of Kilauea from West
Highcastle lava delta to Pu`u `O`o in upper right skyline
168. Intrusive vs. Extrusive
Igneous Rocks
• Intrusive igneous rocks—magma cools
beneath the crust; crystals have more time to
form; harder, more erosion-resistant rocks
169. Intrusive vs. Extrusive
Igneous Rocks
• Intrusive igneous rocks—magma cools
beneath the crust; crystals have more time to
form; harder, more erosion-resistant rocks
• Extrusive igneous rocks—magma cools on
the surface (lava); crystals don’t have time to
form good crystal faces, if it cools fast
enough, no crystals will form
(obsidian--“volcanic glass”)
177. Sedimentary Rocks
• The result of erosion, transportation, deposition, and
lithification
• Sediment—Weathered rock fragments that have
been transported and deposited, usually by water (or
by air or by glacial ice movements)
179. Erosion
Mechanical or Chemical
• Mechanical weathering—The physical force of a
particular process acting on rocks, such as hydraulic
action pounding rocks in a riverbed
180. Erosion
Mechanical or Chemical
• Mechanical weathering—The physical force of a
particular process acting on rocks, such as hydraulic
action pounding rocks in a riverbed
- OR -
181. Erosion
Mechanical or Chemical
• Mechanical weathering—The physical force of a
particular process acting on rocks, such as hydraulic
action pounding rocks in a riverbed
- OR -
• Chemical weathering—Chemical reactions, usually in
the presence of water, which operate to change the
structure of the minerals, and break them apart
– (Example: iron in the presence of water and oxygen,
incorporating those elements into its structure,
expanding as it becomes rust, breaking rock apart)
182. Transportation
• Distance of transport and speed of the fluid
medium determine size, roundness and
sorting of transported material
183. Transportation
• Distance of transport and speed of the fluid
medium determine size, roundness and
sorting of transported material
185. Deposition
• Deposition generally occurs in flat layers
called strata (or “beds”)
• Principle of Original Horizontality
states that material is originally
deposited in horizontal layers and
later is shifted as it is affected by
crustal movements
186. Deposition
• Deposition generally occurs in flat layers
called strata (or “beds”)
• Principle of Original Horizontality
states that material is originally
deposited in horizontal layers and
later is shifted as it is affected by
crustal movements
187. Deposition
• Deposition generally occurs in flat layers
called strata (or “beds”)
• Principle of Original Horizontality
states that material is originally
deposited in horizontal layers and
later is shifted as it is affected by
crustal movements
193. Lithification
Compaction and cementation
• Lithification is the process of turning
sediment into rock
–As sediment is deposited, the addition of more
layers causes compaction
194. Lithification
Compaction and cementation
• Lithification is the process of turning
sediment into rock
–As sediment is deposited, the addition of more
layers causes compaction
• (“trash compactor”)
195. Lithification
Compaction and cementation
• Lithification is the process of turning
sediment into rock
–As sediment is deposited, the addition of more
layers causes compaction
• (“trash compactor”)
–Dissolved minerals such as silica recrystallize in
pore spaces
196. Lithification
Compaction and cementation
• Lithification is the process of turning
sediment into rock
–As sediment is deposited, the addition of more
layers causes compaction
• (“trash compactor”)
–Dissolved minerals such as silica recrystallize in
pore spaces
–Sediment grains are cemented together
199. Three Main Types of
Sedimentary Rocks
• Clastic (or detrital)
– Formed from pieces of
other rocks
200. Three Main Types of
Sedimentary Rocks
• Clastic (or detrital)
– Formed from pieces of
other rocks
• Chemical
201. Three Main Types of
Sedimentary Rocks
• Clastic (or detrital)
– Formed from pieces of
other rocks
• Chemical
– Dissolved mineral
compounds that solidify
again (precipitates/
evaporites)
202. Three Main Types of
Sedimentary Rocks
• Clastic (or detrital)
– Formed from pieces of
other rocks
• Chemical
– Dissolved mineral
compounds that solidify
again (precipitates/
evaporites)
• Organic
203. Three Main Types of
Sedimentary Rocks
• Clastic (or detrital)
– Formed from pieces of
other rocks
• Chemical
– Dissolved mineral
compounds that solidify
again (precipitates/
evaporites)
• Organic
– Formed from the tissues
of living things
206. Two types of metamorphism
• Regional metamorphism
207. Two types of metamorphism
• Regional metamorphism
–Occurs over 100s or 1000s of sq. miles
208. Two types of metamorphism
• Regional metamorphism
–Occurs over 100s or 1000s of sq. miles
–Common in subduction zones
209. Two types of metamorphism
• Regional metamorphism
–Occurs over 100s or 1000s of sq. miles
–Common in subduction zones
• Contact metamorphism
210. Two types of metamorphism
• Regional metamorphism
–Occurs over 100s or 1000s of sq. miles
–Common in subduction zones
• Contact metamorphism
–Localized
211. Two types of metamorphism
• Regional metamorphism
–Occurs over 100s or 1000s of sq. miles
–Common in subduction zones
• Contact metamorphism
–Localized
–Heat and pressure of rising, intruding magmas
“bakes” surrounding rocks
213. Parent Rock
• Parent rock—Name given to the original rock before
the addition of heat and/or pressure
– what you start with will determine what you end up with
quartzite gneiss
214. Parent Rock
• Parent rock—Name given to the original rock before
the addition of heat and/or pressure
– what you start with will determine what you end up with
quartzite gneiss
217. Foliation
• The arrangement of mineral crystals into
parallel or nearly parallel bands
–The classification of metamorphic rocks is
generally based on the amount of foliation in the
rock
