PLATE TECTONICS

Chapter 4

SECTION 1 VOCABULARY

Inside the EarthCrustMantleCoreLithosphereAsthenosphereMesosphereTectonic Plate

THE COMPOSITION OF THE EARTH The Crust

5-100km thickThinnest layer

Two typesContinentalOceanicMade of…

THE COMPOSITION OF THE EARTH The Mantle

ThickerMost of the mass

Crust too thick Observations Ocean floor Made of…

THE COMPOSITION OF THE EARTH The Core

Mantle to the coreMade of…Not made of..

1/3 of the Earth’s mass

THE PHYSICAL STRUCTURE OF THE EARTH

Five layers Inner Core

Solid, dense Outer Core

Liquid layer Mesosphere

Strong Asthenosphere

Plastic layer Lithosphere

Tectonic plates

TECTONIC PLATES Names of the

plates Fit together Difference

OceanContinent

Plates include… Like ice cubes

MAPPING OF THE EARTH’S INTERIOR

Never drilled through the crust

Seismic waves Seismographs

SECTION 2 VOCABULARY Restless Continents

Continental DriftSea-floor Spreading

WEGENER’S CONTINENTAL DRIFT HYPOTHESIS Alfred Wegener

Continental DriftFit togetherSimilar types of

rocks and climatic conditions

THE BREAKUP OF PANGAEA

Observations Single, huge

continent (supercontinent)

245 million years ago

Laurasia and Gondwana (180 million years ago)

SECTION 3 VOCABULARY The Theory of Plate Tectonics

Plate tectonicsConvergent BoundaryDivergent BoundaryTransform Boundary

TECTONIC PLATE BOUNDARIES Plates Touch Three Types

Convergent Boundary

Divergent Boundary

Transform Boundary

How they move earthquakes

CONVERGENT BOUNDARY Collide Kind of crust Three Types

DIVERGENT BOUNDARY Separate New Sea Floor Mid-Ocean

Ridges

TRANSFORM BOUNDARIES

Slide Past Each other horizontally

San Andreas Fault

POSSIBLE CAUSES OF TECTONIC PLATE MOTION Plate Tectonic

Theory Solid Rock Flows Changes in

Density Thermal Energy Three possible

causes

THREE CAUSES OF TECTONIC PLATE MOTION

Ridge Push Convection Slab Pull

TRACKING TECTONIC PLATE MOTION Type and Shape

of the plate Interacts with

Plates So Slow and

Gradual GPS Radio Signals

SECTION 4 Deforming the Earth’s Crust Vocabulary

CompressionTensionFoldingFaultUpliftSubsidence

DEFORMATION Spaghetti

BendingBreaking

Rock Layers Stress

COMPRESSION AND TENSION

CompressionSqueezed or

CollidedConvergentMountain Ranges

TensionStretchDivergentMid-Ocean Ridge

FOLDING Bending of Rock

LayersHorizontal layers

Types of FoldsAnticlinesSynclinesMonoclineDifferent sizes

FAULTING Stress is applied Fault Blocks Hanging wall

and footwall Two Types

Normal faultReverse fault

TWO TYPES OF FAULTS Normal fault

Tension Pull Rocks Apart

Reverse FaultsCompression that

pushes rocks together

TELLING THE DIFFERENCE BETWEEN FAULTS Look at the order

of sedimentary rock layers

Compare the two dark layers

STRIKE-SLIP FAULTS Third Type of

Fault Opposing forces

cause rock to break and move horizontally

Move left or right San Andreas

Fault

PLATE TECTONICS AND MOUNTAIN BUILDING Plates Collide

Land features start as…

Can become …Mountains existAndes MountainsCompression or

tension

THREE DIFFERENT KINDS OF MOUNTAINS

Folded Mountains Highest Convergent (collide) Appalachian Mtns.

Fault-Block Mountains Tension Drop Down Tilted up

Volcanic Mountains Major (Convergent) Sinks Islands Ring of Fire

UPLIFT AND SUBSIDENCE Vertical

MovementsUplift

Higher elevations May or May Not Be

DeformedSubsidence

Sinking No Deformation

UPLIFT AND SIBSIDENCE Uplifting of

Depressed Rock Formation of Mtns. Without Deformation

Rebound Weight removed

Subsidence of Cooler Rock Hot More Space Less Volume (Subsides)

Tectonic Letdown Stretched rift zones Stress