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 Pillow Lavas Remember: Melting the mantle makes 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 Recording the Break-up Beginning the Break-up 225 Ma

Youthful Oceanic Crust

Convergent Boundaries Making 2 nd Stage Crust Ancient Continental Crust

Convergent Boundaries- Where the Action Is!! Ocean- Continent Continent - Continent Ocean - Ocean Earthquakes Volcanoes

Mt. St. Helens May 18, 1980 Consequences of Convergence Explosive Volcanism

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

San Francisco Earthquake April 18, 1906 Mag 7.8 The San Andreas Fault

MantlePlumes/Hotspots

Mantle Hotspots in the Oceans Sites of overthickened crust and the formation of ocean islands and plateaus

Famous Hotspots Hawaii Yellowstone Iceland

The Grand Unifying Theory of the Earth Paradigm -