The Rock CycleThinking about relationships among the

major rock groups (Igneous, Sedimentary, and Metamorphic)

Also see figure 1.12 on page 16 of the student textbook.

3

Major Rock Groups• Igneous

– Formed from a melt (i.e. molten rock)– Plutonic (i.e. intrusive): slow cooling and crystallization

from a magma.– Volcanic (i.e. extrusion): quick cooling at the surface (lava).

• Sedimentary– Formed at the Earth’s surface.– Clastic (mineral fragments or grains, clays)– Chemical (crystalline chemical/biochemical precipitates)

• Metamorphic– Changed by pressure, temperature and hot chemical fluids.

Fig. 2.9

MAGMA

5

MAGMA

Crystallization

IGNEOUS

6

MAGMA

IGNEOUS

Plutonic

Crystallization

7

MAGMA

Volcanic

IGNEOUS

Plutonic

Crystallization

8

MAGMA

Volcanic

IGNEOUS

Plutonic

Uplift

Crystallization

Weathering

9

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

Uplift

Crystallization

Weathering SEDIMENT

10

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

WeatheringErosion

Transport

Deposition

11

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

WeatheringErosion

Transport

Deposition

Lithification

Remember

• Lithification =– Sediment turns to sedimentary rock by the processes of

compaction and cementation.

13

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

Crystallization

WeatheringErosion

Transport

Deposition

Lithification

Remember

• Note that the process of melting is not involved or associated with metamorphism.

• Note that the grade of metamorphism could be increased (e.g., low-grade metamorphic rocks to high-grade metamorphic rocks) as the conditions of metamorphism are increased.

15

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

Deposition

Can you see

any shortcuts?

Lithification

16

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

Deposition

Lithification

• 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 Earth’s surface as well as the Earth’s interior.

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

In Conclusion…

19

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

WeatheringErosion

Transport

Deposition

Lithification