Processes of Lithosphere

Processes of Lithosphere

Lithosphere

• Rigid outermost shell of a rocky planet– On earth, comprises the crust and the upper

mantle

The Rock CycleThinking about relationships among

the major rock groups

5

Major Rock Groups• Igneous– Formed from a melt (molten rock)– Plutonic (intrusive):slow cooling and crystallization– Volcanic (extrusion): quick cooling at the surface

• Sedimentary– Formed at the Earth’s surface

• Metamorphic– Changed by pressure, temperature and fluids.

Fig. 2.9

MAGMA

7

MAGMA

Crystallization

IGNEOUS

8

MAGMA

IGNEOUS

Plutonic

Crystallization

9

MAGMA

Volcanic

IGNEOUS

Plutonic

Crystallization

10

MAGMA

Volcanic

IGNEOUS

Plutonic

Uplift

Crystallization

Weathering

Weathering• Chemical – changing composition

(acid rain)

• Physical – Breaking apart rocks, moving soils, etc

• Soil is result of weathering of rocks and includes weathered particles

12

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

Uplift

Crystallization

Weathering SEDIMENT

13

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

Weathering Erosion

Transport

Deposition

14

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

Uplift

Crystallization

Weathering Erosion

Transport

Deposition

15

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

Crystallization

Weathering Erosion

Transport

Deposition

16

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

Weathering Erosion

Transport

DepositionCan you see

any shortcuts?

17

MAGMA

Volcanic

IGNEOUS

Plutonic

SEDIMENT

SEDIMENTARY

METAMORPHIC

UpliftBurial

Increased P&T

MeltingCrystallization

Weathering Erosion

Transport

Deposition

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

• It is powered by the interior heat of the Earth

• The energy from the sun• It involves processes on

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

In Conclusion…

The Structure of the Earth and Plate Tectonics

Structure of the Earth

• The Earth is made up of 3 main layers:– Core– Mantle– Crust

Inner core

Outer core

Mantle

Crust

The Crust• This is where we live!

• The Earth’s crust is made of:

Continental Crust- buoyant (less dense than oceanic crust)

Oceanic Crust- dense (sinks under continental crust)

What is Plate Tectonics?

• If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

Plate Tectonics

• The Earth’s crust is divided into 12 major plates which are moved in various directions.

• This plate motion causes them to collide, pull apart, or scrape against each other.

• Each type of interaction causes a characteristic set of Earth structures or “tectonic” features.

• The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

World Plates

What are tectonic plates made of?

• Plates are made of rigid lithosphere.

The lithosphere is made up of the crust and the upper part of the mantle.

Plate Movement

• “Plates” of lithosphere are moved around by the underlying hot mantle convection cells

• Divergent

• Convergent

• Transform

Three types of plate boundary

• Spreading ridges– As plates move apart new material is erupted

to fill the gap

Divergent Boundaries

• Iceland has a divergent plate boundary running through its middle

Iceland: An example of continental rifting

• There are three styles of convergent plate boundaries– Continent-continent collision– Continent-oceanic crust collision– Ocean-ocean collision

Convergent Boundaries

• Forms mountains, e.g. European Alps, Himalayas

Continent-Continent Collision

Himalayas

• Called SUBDUCTION• Area is called the subduction zone

Continent-Oceanic Crust Collision

• Where plates slide past each other

Transform Boundaries

Above: View of the San Andreas transform fault

…what’s the connection?

Volcanoes and Plate Tectonics…

Volcanism is mostly focused at plate margins

Pacific Ring of Fire

- Subduction - Rifting - Hotspots

Volcanoes are formed by:

Subduction

• Form new melt that will rise through the crust to be erupted at the surface

Rifting

• Form new melt that will rise through the crust to be erupted at the surface

Hot Spots

• Does not occur along a plate boundary. • Form in the middle of tectonic plates

Volcanic Eruptions

• Pyroclastic Flow – cloud of ash and debris– Travel at hundreds of mph– Hundreds of degrees

Volcanic Eruptions

• Lahar – mud flows which are very destructive to landscape

Volcanic Eruptions

• “Ash” emitted includes small stones• Very dense• Chokes life• Blots out sunlight• Causes wide range temperature drops

http://www.youtube.com/watch?v=UK--hvgP2uY

…what’s the connection?

Earthquakes and Plate Tectonics…

• As with volcanoes, earthquakes are not randomly distributed over the globe

• At the boundaries between plates, friction causes them to stick together. When built up energy causes them to break, earthquakes occur.

Figure showing the distribution of earthquakes around the globe

Where do earthquakes form?

Figure showing the tectonic setting of earthquakes

Fault Lines

• Strike – slip

• Reverse

• Normal

Earthquake Anatomy

• Focal point – where the actual earth quake originated underground

• Epicenter – location of earth quake on earth’s surface– Above the focal point

Earthquake Anatomy

• P Waves (primary) – waves which travel fastest, first, and moves through any material– Reach seismographs – Moves land back and forth

• S Waves (secondary) – actual surface waves which travel slower and only moves through solids– Moves land up and downhttp://www.teara.govt.nz/en/interactive/

4403/primary-and-secondary-waves

Results..

• Land destruction/alteration• Fire (breaking of gas and power lines)• Buildings destroyed• Tsunami’s

Tsunami

• “Harbor Wave”