Transcript Crust

Convection Currents Guided Reading
 Vocabulary Cards
 Checking Pen

Tectonic Plates
 Theory of Plate Tectonics
 Convergent Plate Boundary
 Divergent Plate Boundary
 Transform Plate Boundary
 Continental Drift Theory
 Sea-Floor Spreading Theory
 Subduction

Large pieces of Earth’s crust (lithosphere)
that can move, collide, or slide past
each other
 Causes:

› Continental drifting
› Earthquakes
› Volcanoes
› Mountains
› Ocean trenches
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
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
Two tectonic plates moving away from
each other
 Creates:

› Volcanoes
› Mid-Ocean Ridge
› New Ocean Floor
› Rift Valley

Two tectonic plates that move or slide
past one another
› Opposite or same direction at different rates

Creates:
› Earthquakes
› Fault lines
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
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

Process where the ocean floor sinks
beneath an ocean trench and melts
back into the Mantle
Crust
 Lithosphere
 Mantle
 Outer Core
 Inner Core
 Magma
 Lava
 Convection Currents

Composition: Silicon, Oxygen, and
Aluminum
 Types:

› Continental Crust: solid & rocky outer layer
› Oceanic Crust: thin & dense material
Includes the Earth’s Crust & Upper
Mantle
 Divided into small and large tectonic
plates that help move the continental
and oceanic crust

Composition: Silicon, Oxygen, and
Magnesium
 Thickest layer
 Convection currents are located here


Composition: Molten (liquid) Iron &
Nickle
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

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


Molten rock found beneath the Earth’s
surface

Molten rock found on the Earth’s surface