The Lithosphere

Day 1

• Objective:Objective:–I can explain how the Earth is

structured

–I can explain how the material of earth is changed

Layers of the Earth

• Defined by composition

• 3 Major Zones–Crust

–Mantel

–Core

The Crust

• Thin, rocky outer layer

• Either oceanic or continental– Oceanic is 7-km

thick

– Continental is 8-75 km thick

The Mantle

• 82% of Earth’s volume

• 2890-km thick

• Solid rock at the top

• Liquid rock at the bottom

The Core

• Composed of an iron-nickel alloy

• Extreme pressure found at the center

Layers based on Physical Properties

• Lithosphere– Crust and Upper

most mantle

– Cool, rigid shell

– 100-km thick

• Asthenosphere– Below the Lithosphere

– Soft, comparatively weak layer

– Rocks close to melting

• Outer Core– Liquid layer

– 2260-km thick

–Metallic iron flow creates Earth’s magnetic field

• Inner Core– Solid layer

– Radius of 1220-km

– High temperature

– High pressure

–Mostly nickel

What is a ROCK?

• Solid mass of minerals or mineral matter that naturally occurs as part of our planet

• Three types– Igneous

– Sedimentary

–Metamorphic

Types of Rocks• Igneous Rock– Forms when lava or

magma cools

• Sedimentary Rock–When existing rocks are

broken down into pieces then compacted and cemented together

• Metamorphic Rocks–When existing rocks are

changed by heat and pressure

What is the ROCK CYCLE?

• Origin of the three basic rocks and interrelatedness of Earth’s materials and processes

The Rock Cycle

DAY 2

• Objective:Objective:–I can explain about the theory of plate

tectonics

–I can describe plate interactions

What is Continental Drift?

• Proposed by Alfred Wegener

• Stated that the continents had once been joined to form a single supercontinent

• Supercontinent was called Pangaea

What did the Theory Say?

• Occurred 500 million years ago

• Pangaea broke apart 200 million years ago

• Continents “Drifted” (moved) to present positions

• Continents “broke” through the oceans

• North America and Africa split 135 million years ago

Evidence of Continental

Drift

• Shorelines look like they fit together

• Same fossil organisms found on different landmasses

• Several mountain belts end at one coastline, only to reappear on a land mass across the ocean

• Ancient Climates relate

The Theory of Plate Tectonics

• Earth’s outer shell consists of individual plates

• Plates interact in various ways when they move along

Plate Boundary Activities

• Earthquakes

• Volcanoes

• Mountain Building

• Sea Floor Spreading

Earth’s Major Plates

• Top 7– African

– Antarctic

– Eurasian

– Australian-Indian

– North American

– Pacific

– Southern American

• Other Plates– Arabian

– Caribbean

– Cocos

– Nazca

– Phillippine

– Scotia

DAY 3• ObjectiveObjective–I can explain how the plates

interact with each other

Types of Plate Boundaries

• Divergent Boundary

• Convergent Boundary

• Transform Fault Boundary

Divergent Plate Boundary• When two plates move

apart

• Also called spreading centers

• New crust is created (mainly seafloor)– Known as sea floor

spreading

• Causes Ocean Ridges and Rift Valleys (on continents)

Convergent Plate Boundary

• Two plates move toward each other

• 3 versions– Oceanic-Continental

– Continental-Continental

– Oceanic-Oceanic

Oceanic-Continental Convergent Boundary

• Oceanic plate goes beneath the continental plate

• Causes– Subduction zones

– Trenches

– Continental Volcanic arcs (ex: The Andes)

Continental-Continental Convergent Boundary

• Two continental plates collide

• Causes Mountains to form–Ex: Appalachians,

Himalayas, Alps

Oceanic-Oceanic Convergent Boundary

• One oceanic plate goes beneath another oceanic plate

• Causes Volcanic Island Arc–Ex: Aleutian Islands

Transform Fault Plate Boundary

• Two plates grind past each other

• No production or destruction of lithosphere

• Causes Earthquakes–Ex: San Francisco

DAY 4• Objective:Objective:–I can explain how faults differ

–I can explain the relation between boundaries and plate tectonics

What Causes Plate Movement?

• Convective Flow–The circulation of

magma that pushes & pulls plates

• Driving Force is heat

What is a Fault?

• Fracture in Earth where movement has taken place

• Most times near Plate Boundaries

Parts of a Fault

• Hanging Wall–Rock above the

fault line

• Foot Wall–Rock below the

fault line

What are the types of Faults?

•Normal

•Reverse

•Thrust

•Strike-Slip

Types of Faults• Normal Fault– Occurs when the

hanging wall block moves down relative to the footwall block

• Reverse Fault– Occurs when the

hanging wall block moves up relative to the footwall block

• Thrust Fault– A reverse fault with

dips of less than 45 degrees

• Strike-Slip Fault–Movement is horizontal;

“side-by-side motion”

Evidence of Plate Tectonics

1. Paleomagnetism– Most persuasive

evidence

– Ancient magnetism found in the rocks

– Records show a shift in the poles

2. Earthquake Patterns– Connection between

deep-focus earthquakes and ocean trenches

3. Ocean Drilling– Young rocks are

near ocean ridge crest

– Oldest rocks are near the continental margins

4. Hot Spots– A concentration of

heat in the mantle capable of producing magma, which rises to Earth’s surface

– Supports that the plates move over Earth’s surface

– Ex: Hawaiian Island Chain