The Rock CycleThinking about relationships among

the major rock groups

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Major Rock Groups• Igneous

– Formed from a magma (molten rock) either erupting onto the surface or being held below the surface and cooling.

• Sedimentary– Formed from sediments such as mud, sand and gravel

that accumulate in layers on the floor of places like the sea, lakes or river deltas. These sediments have been compacted and often cemented together to form rocks

• Metamorphic– formed beneath the surface when older igneous and

sedimentary rocks are transformed by a combination of heat and pressure.

Fig. 2.9

MAGMA

4

MAGMA

Crystallization

IGNEOUS

5

MAGMA

IGNEOUS

Plutonic

Crystallization

6

MAGMA

Volcanic

IGNEOUS

Plutonic

Crystallization

7

MAGMA

Volcanic

IGNEOUS

Plutonic

Uplift

Crystallization

Weathering

8

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

Uplift

Crystallization

Weathering SEDIMENT

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MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

WeatheringErosion

Transport

Deposition

What is Weathering & Erosion?

• Weathering is the breaking down of rocks by natural processes. Weathering can break rocks down in three different ways, described as physical weathering, chemical weathering and biological weathering.

• Erosion is the movement of soil and other weathered material from one place to another. It can be done by wind or water, and the water can be moving quickly like a river, repetitively like the sea or slowly like a glacier.

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11

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

WeatheringErosion

Transport

Deposition

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MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

Crystallization

WeatheringErosion

Transport

Deposition

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MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

DepositionCan you see

any shortcuts?

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MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

Deposition

• The rock cycle demonstrates the relationships among the three major rock groups

• It is powered by the interior heat of the Earth

• As well as earth’s momentum and…

• The energy from the sun

• It involves processes on the Earth’s surface as well as the Earth’s interior

• It connects the “hydrologic cycle” with the “tectonic cycle”.

In Conclusion…

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MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

Deposition

Tasks to complete

1. Draw a simple diagram of the Rock Cycle

2. Write a paragraph to explain what the diagram shows. Include the processes linking each type of rock

3. Erosion and weathering are two processes that are easily confused. Explain what each process does

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