210 likes | 404 Views
Plate Tectonic Theory – The Earth’s outer shell (lithosphere) is composed of rigid plates that are moving relative to one another. Plate Tectonics drives 2 Stages of Crust-making 1. Mantle partially melts to make ocean crust 2. Ocean crust melts to make continental crust.
E N D
Plate Tectonic Theory – The Earth’s outer shell (lithosphere) is composed of rigid plates that are moving relative to one another.
Plate Tectonics drives 2 Stages of Crust-making 1. Mantle partially melts to make ocean crust 2. Ocean crust melts to make continental crust
What moves the Plates? Slab Pull Mantle Push Ridge Slide
Divergent Plate Boundaries Mid-ocean Ridges Where Stage 1 Crust is Made
Basalt – Rock Type of the Oceanic Crust Remember: Melting the mantle makes mafic magma!!Always
Continental Rifting The creation of new ocean basins
200 Ma The Break-up of Pangea 75 Ma 125 Ma
Convergent Boundaries Making 2nd Stage Crust Ancient Continental Crust
Convergent Boundaries- Where the Action Is!! Ocean - Ocean Earthquakes Ocean- Continent 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 Boundaries San Francisco Earthquake April 18, 1906 Mag 7.8
Mantle Hotspots Creation of overthickened oceanic crust
Famous Hotspots Yellowstone? Hawaii Iceland