You Need the Following: Convection Currents Guided

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Label Your Notecards Tectonic Plates Theory of Plate Tectonics Convergent Plate Boundary Divergent Plate Boundary Transform Plate Boundary Continental Drift Theory Sea-Floor Spreading Theory Subduction

Tectonic Plates Large pieces of Earth’s crust

(lithosphere) that can move, collide, or slide past each other

Causes:› Continental drifting› Earthquakes› Volcanoes› Mountains› Ocean trenches

Theory of Plate Tectonics States pieces of Earth’s lithosphere are in constant, slow motion, driven by convection currents in the Mantle

Explains: › Plate formation› Plate movement› Subduction of plates

Convergent Plate Boundary

Two tectonic plates moving toward each other and collide

Types = Creates: › Continental-continental = Mountains & their

ranges› Oceanic-oceanic = Island Arcs› Continental-oceanic = Subduction Zone &

Trenches

Divergent Plate Boundary

Two tectonic plates moving away from each other

Creates: › Volcanoes› Mid-Ocean Ridge› New Ocean Floor› Rift Valley

Transform Plate Boundary

Two tectonic plates that move or slide past one another› Opposite or same direction at different rates

Creates: › Earthquakes› Fault lines

Continental Drift Theory Continents have shifted their position

over geologic time One time, all land masses were

connected to form Pangaea Evidence:

› Continents look to fit together› Minerals, fossils, and mountains now on

different continents would match if they were together

Evidence from Minerals, Fossils, and Mountains

Sea-Floor Spreading Theory

Magma and molten material rises from the convection currents to create a divergent boundary, separating plates

Helps move the continents Oceans are spreading ~2 cm per year Creates:

› New Ocean Floor Crust› Mid-Ocean Ridges

Subduction Process where the ocean floor sinks

beneath an ocean trench and melts back into the Mantle

Subduction

Label Your Notecards Crust Lithosphere Mantle Outer Core Inner Core Magma Lava Convection Currents

Crust Composition: Silicon, Oxygen, and

Aluminum Types:

› Continental Crust: solid & rocky outer layer› Oceanic Crust: thin & dense material

Lithosphere Includes the Earth’s Crust & Upper

Mantle Divided into small and large tectonic

plates that help move the continental and oceanic crust

Mantle Composition: Silicon, Oxygen, and

Magnesium Thickest layer Convection currents are located here

Outer Core Composition: Molten (liquid) Iron &

Nickle

Inner Core Composition: Solid Iron & Nickle Solid because of the pressure from the

layers above Solid inner core spins in the molten

(liquid) outer core› Creates the Earth’s Magnetic Field

Hottest layer

Convection Currents Happens in the Middle Mantle

› Has hot, dense rock that slowly flows Movement created moves the tectonic

plates in the Lithosphere Caused by hot material, deep in the

Mantle, being heated by the Core to rise then cool and sink again

Magma Molten rock found beneath the Earth’s

surface

Lava Molten rock found on the Earth’s

surface