Download Unit 3 Rocks, Soil, Erosion and MM

Unit 3 Rocks, Soil, Erosion and
Mass Movements
Including the Geological History of
North Carolina!
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
The particles were lithified
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
The particles were lithified (turned into rock) by:
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
The particles were lithified (turned into rock) by:
compaction – great pressure from
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
The particles were lithified (turned into rock) by:
compaction – great pressure from the layers of
sediment above. It can only work if the sediments
are
Classification of Rock
Most rocks have a number of minerals in common.
Rocks are grouped on the basis of their physical and
chemical properties, but most importantly, their origin.
1. Sedimentary Rocks
Most form under water. Layering (“stratification”) will
indicate this.
Sedimentary rocks are classified according to the way
they were formed and what was deposited:
A. Clastics – weathered particles from pre-existing rocks
The particles were lithified (turned into rock) by:
compaction – great pressure from the layers of
sediment above. It can only work if the sediments
are small (e.g. shale & siltstone from clay and silt)
Cementation – is needed for larger particles.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified,
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers.
alabaster
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers.
alabaster
limestone
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers. Evaporites will form if the rate of
evaporation is great.
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers. Evaporites will form if the rate of
evaporation is great.
halite
Cementation – is needed for larger particles. A
cement (a mineral that dissolves in water - - CaCO3)
holds the sediments together (e.g. sandstone &
conglomerate from sand & pebbles).
Clastics are usually stratified, and often contain
fossils. These help indicate what conditions existed at
the time of sedimentation.
B. Chemical Sedimentary rocks formed from material
that was dissolved in the water. When the water gets
saturated, the minerals precipitate out and form solid
rock layers. Evaporites will form if the rate of
evaporation is great.
All chemical sedimentary rocks are monomineralic.
C. Organic sedimentary rocks form as a result of biologic
processes
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal]
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal] or
cementing of shell material [e.g. fossil limestone]).
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal] or
cementing of shell material [e.g. fossil limestone]).
Oolitic limestone
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal] or
cementing of shell material [e.g. fossil limestone]).
Oolitic limestone
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal] or
cementing of shell material [e.g. fossil limestone]).
Oolitic limestone
C. Organic sedimentary rocks form as a result of biologic
processes (decay of plant material [e.g. coal] or
cementing of shell material [e.g. fossil limestone]).
The shell material, however, is not organic.
2. Nonsedimentary Rocks
2. Nonsedimentary Rocks
A. Igneous -
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed under the
earth’s surface.
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed under the
earth’s surface. It usually takes a long time to
cool, so the minerals crystallize at different
temperatures and separate.
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed under the
earth’s surface. It usually takes a long time to
cool, so the minerals crystallize at different
temperatures and separate. Dark colors (mafic)
harden first (higher temp); while light colors
(felsic) harden last.
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed under the
earth’s surface. It usually takes a long time to
cool, so the minerals crystallize at different
temperatures and separate. Dark colors (mafic)
harden first (higher temp); while light colors
(felsic) harden last.
The longer it takes for magma to cool, the _____
the crystals will be
2. Nonsedimentary Rocks
A. Igneous - form as lava or magma cools &
solidifies.
1. Intrusive (plutonic) rocks formed under the
earth’s surface. It usually takes a long time to
cool, so the minerals crystallize at different
temperatures and separate. Dark colors (mafic)
harden first (higher temp); while light colors
(felsic) harden last.
The longer it takes for magma to cool, the larger
the crystals will be (coarse grained).
Intrusive Igneous Rocks
granite
Intrusive Igneous Rocks
diorite
Intrusive Igneous Rocks
gabbro
Intrusive Igneous Rocks
Pegmatite
All molten rock originates in the upper mantle and
lower crust.
All molten rock originates in the upper mantle and
lower crust.
All molten rock originates in the upper mantle and
lower crust. Heat comes from pressure and
radioactive decay of the materials deep within the
earth.
All molten rock originates in the upper mantle and
lower crust. Heat comes from pressure and
radioactive decay of the materials deep within the
earth. When magma is forced through cracks in
the bedrock, intrusions are formed.
All molten rock originates in the upper mantle and
lower crust. Heat comes from pressure and
radioactive decay of the materials deep within the
earth. When magma is forced through cracks in
the bedrock, intrusions are formed.
All molten rock originates in the upper mantle and
lower crust. Heat comes from pressure and
radioactive decay of the materials deep within the
earth. When magma is forced through cracks in
the bedrock, intrusions are formed. If cracks lead
to the surface, extrusions are formed (volcanoes).
All molten rock originates in the upper mantle and
lower crust. Heat comes from pressure and
radioactive decay of the materials deep within the
earth. When magma is forced through cracks in
the bedrock, intrusions are formed. If cracks lead
to the surface, extrusions are formed (volcanoes).
2. Extrusive (eruptive or volcanic) rocks form from
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface.
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface. Small crystal
grains indicate that it cooled
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface. Small crystal
grains indicate that it cooled quickly.
Lava cooling into basalt
basalt
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface. Small crystal
grains indicate that it cooled quickly. Glassy
texture shows it cooled very fast (usually under
water).
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface. Small crystal
grains indicate that it cooled quickly. Glassy
texture shows it cooled very fast (usually under
water).
obsidian
2. Extrusive (eruptive or volcanic) rocks form from
lava that cooled on the surface. Small crystal
grains indicate that it cooled quickly. Glassy
texture shows it cooled very fast (usually under
water).
Sometimes the lava is ejected onto the surface and
cools with gases trapped inside pockets
(“vesicles”) in the rock.
pumice
B. Metamorphic Rock – used to be
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas,
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
slate
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
slate
(used to be shale; the
pressure made it darker
& denser, the shale
layers became foliated)
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
quartzite
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
quartzite
(used to be sandstone;
the “scaliness” is from
the distorted sand grains)
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
gneiss
B. Metamorphic Rock – used to be other kinds of rocks
but they were changed as a result of heat, pressure
and/or chemical changes.
1. Regional – occurs over wide areas, usually due to
extreme temperature and pressure conditions.
This happens deep within the crust, usually due
to mountain building processes.
gneiss
(used to be granite; the
heat & pressure made the
minerals recrystallize and
form bands)
2. Contact (thermal) – occurs at the interface of hot
magma and existing rock.
2. Contact (thermal) – occurs at the interface of hot
magma and existing rock. Chemical changes
forming new minerals often occur.
Pix of meta rocks
Quartzite (used to be
sandstone)
2. Contact (thermal) – occurs at the interface of hot
magma and existing rock. Chemical changes
forming new minerals often occur.
More pix of meta
Marble bookends
(used to be
limestone)
We can learn a lot about the environment when rock
formed by looking at its composition,
We can learn a lot about the environment when rock
formed by looking at its composition,
What can we infer
from this rock?
Pix of conglom
We can learn a lot about the environment when rock
formed by looking at its composition,
Large rounded particles imply
that this conglomerate formed
from sediment at the mouth of
a river.
Pix of conglom
We can learn a lot about the environment when rock
formed by looking at its composition, structure,
Foliation in this schist implies
that the basalt underwent
tremendous pressure deep
under the surface.
Pix of schist
We can learn a lot about the environment when rock
formed by looking at its composition, structure and
texture.
The course grains in this
diorite implies that it cooled
deep within the crust.
We can learn a lot about the environment when rock
formed by looking at its composition, structure and
texture.
The course grains in this
diorite implies that it cooled
deep within the crust.
The glassy luster in this
obsidian implies that it
cooled quickly, most likely
under water.
Pix of obsidian
The Rock Cycle
The Rock Cycle
There is evidence that rocks continue to be “recycled”
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
- lava can be seen cooling into igneous rock
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
- lava can be seen cooling into igneous rock
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
- lava can be seen cooling into igneous rock
- the composition of sedimentary rocks suggest that
they had varied origins
conglomerate
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
- lava can be seen cooling into igneous rock
- the composition of sedimentary rocks suggest that
they had varied origins
- some rocks show multiple transformations
The Rock Cycle
There is evidence that rocks continue to be “recycled”
- sedimentation & sedimentary rocks
- similarities between metamorphic & other rocks
- transition zones from unaltered to altered rock can be
found where magma came in contact with local rock
- lava can be seen cooling into igneous rock
- the composition of sedimentary rocks suggest that
they had varied origins
- some rocks show multiple transformations
- the age of rocks ≠ the age of the earth
Oceanic igneous rocks tend to be in the basalt family
Oceanic igneous rocks tend to be in the basalt family
(darker & denser),
Oceanic igneous rocks tend to be in the basalt family
(darker & denser), while continental igneous rocks tend
to be of the granite family
Oceanic igneous rocks tend to be in the basalt family
(darker & denser), while continental igneous rocks tend
to be of the granite family (lighter).
(Basaltic)
Pix of crustal rock
(Granitic)