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 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 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 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 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 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 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 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 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. Chemical Sedimentary rocks formed from material that was

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 (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. Chemical Sedimentary rocks formed from material that was dissolved in the water.

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 (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. 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 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. 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 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. 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 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. 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 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. 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 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. 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.

Organic sedimentary rocks form as a result of biologic processes

Organic sedimentary rocks form as a result of biologic processes (decay of plant material [e.g. coal]

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]).

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

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

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

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 Igneous - form as lava or magma cools & solidifies.

2. Nonsedimentary Rocks Igneous - form as lava or magma cools & solidifies. 1. Intrusive (plutonic) rocks formed

2. Nonsedimentary Rocks Igneous - form as lava or magma cools & solidifies. Intrusive (plutonic) rocks formed under the earth’s surface.

2. Nonsedimentary Rocks Igneous - form as lava or magma cools & solidifies. 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 Igneous - form as lava or magma cools & solidifies. 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 Igneous - form as lava or magma cools & solidifies. 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 Igneous - form as lava or magma cools & solidifies. 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 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 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 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 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 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

Extrusive (eruptive or volcanic) rocks form from lava that cooled on the surface.

Extrusive (eruptive or volcanic) rocks form from lava that cooled on the surface. Small crystal grains indicate that it cooled

Extrusive (eruptive or volcanic) rocks form from lava that cooled on the surface. Small crystal grains indicate that it cooled quickly. basalt Lava cooling into basalt

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).

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

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

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes.

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,

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. Regional – occurs over wide areas, usually due to extreme temperature and pressure conditions.

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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)

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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)

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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

Metamorphic Rock – used to be other kinds of rocks but they were changed as a result of heat, pressure and/or chemical changes. 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)

Contact (thermal) – occurs at the interface of hot magma and existing rock.

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)

Contact (thermal) – occurs at the interface of hot magma and existing rock. Chemical changes forming new minerals often occur. Marble bookends (used to be limestone) More pix of meta

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). (Granitic) (Basaltic) Pix of crustal rock