THE LANGUAGE OF THE
EARTH – PART V
PLATE TECTONIC
THEORY
Plate Tectonic Theory
The Earth’s outer shell (lithosphere) is composed of rigid
plates that are moving relative to one another.
Internal Structure of the Earth
Compositional Layers
Physical
Layers
Plate Tectonics Drives Two Stages of Crust-making
A. Mantle partially melts to make ocean crust
B. Ocean crust partially melts to make continental crust
What Moves the Plates?
Mantle Push
Ridge Slide
Slab
Pull
Types of Plate Boundaries
Divergent Plate Boundaries
Mid-ocean Ridges
Where Stage 1 Crust is Made
Basalt
Rock Type of the Ocean Crust
Remember:
Melting the mantle makes
Pillow Lavas
mafic magma!! Always
Hydrothermal Alteration of Ocean Crust
Preparing it for Stage 2 Melting
“Black Smokers”metal-rich hydrothermal waters
venting into the ocean floor
Continental
Rifting
The creation
of new
ocean basins
Continental Rifting
and
The Break-up
of Pangea
Age of the Atlantic Ocean Crust
Beginning the Break-up
225 Ma
Recording the Break-up
Youthful Oceanic Crust
Convergent Boundaries
Making 2nd Stage Crust
Ancient
Continental
Crust
Convergent BoundariesWhere the Action Is!!
Ocean - Ocean
Earthquakes
OceanContinent
Volcanoes
Continent - Continent
Consequences of Convergence
Explosive Volcanism
Mt. St. Helens
May 18, 1980
Consequences of Convergence
Mountain Building and
Rock Deformation
Consequences of Convergence
Earthquakes
Banda Ache, Dec. 26, 2004
OROGENESIS
The Culmination
of Convergence
Transform
Fault Plate
Boundaries
The San
Andreas Fault
San Francisco Earthquake
April 18, 1906 Mag 7.8
Mantle
Plumes/
Hotspots
Mantle
Hotspots in
the Oceans
Sites of
overthickened
crust and the
formation of
ocean islands
and plateaus
Famous Hotspots
Yellowstone
Hawaii
Iceland
The Grand Unifying Theory of the Earth
Paradigm -