Download The What of Plate Tectonics

The What of Plate
Tectonics
Introduction to Plate Tectonics
The Earth is made up of plates that move around the
surface of the Earth.
• the uppermost mantle, along with the crust, acts
as a strong, rigid layer. This layer is known as the
lithosphere
• a plate is one of numerous rigid sections of the
lithosphere that move as a unit over the material
of the lower mantle.
Plate Boundaries
Plate Tectonics
Three Types of
Plate Boundaries
Plate Boundaries
 Divergent boundaries are the place where two plates
move apart. Makes new lithosphere.
i.e. Mid Ocean Ridge, Death Valley CA
 Convergent boundaries form where two plates move
together. Destroys existing lithosphere
i.e. Japan/Indochina
 Transform fault boundaries are margins where two
plates grind past each other without the production
or destruction of the lithosphere.
i.e. San Andreas Fault
3 Types of Converging boundaries
• Generally results in mountain formation
• It’s all about density
• D = M/V
– Relationship between how much matter there is
to how much space it takes up
– More matter in less space = more dense
Lithospheric Plates
3 Types of Converging boundaries
• Generally results in mountain formation
• It’s all about density
• Continental-Continental
– Mountain ranges form
• Oceanic-Continental
– Oceanic subducts
– Volcanoes, mountains, and trenches form
• Oceanic-Oceanic
– One subducts
– Volcanoes form
Oceanic-Continental
Convergent Boundary
Oceanic-Oceanic
Convergent Boundary
Continental-Continental
Convergent Boundary
Collision of India and Asia
Actions at Divergent Boundaries
 Oceanic ridges are continuous elevated zones on
the floor of all major ocean basins. The rifts at the
crest of ridges represent divergent plate
boundaries
 Rift valleys are deep faulted structures found
along the axes of divergent plate boundaries. They
can develop on the seafloor or on land
 Seafloor spreading produces new oceanic
lithosphere
Actions at Transform Fault Boundaries
 Plates grind past each other without
destroying lithosphere
• Most join two segments of a mid-ocean ridge.
• At the time of formation, they roughly parallel
the direction of plate movement.
• They aid the movement of oceanic crustal
material.
Transform Fault Boundary