plate tectonics drives 2 stages of crust-making 1. mantle partially melts to make ocean crust
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
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-making1. Mantle partially melts to make ocean crust2. Ocean crust melts to make continental crust
What moves the Plates?
Slab Pull Mantle Push Ridge Slide
Types of Plate Boundaries
Divergent Plate BoundariesMid-ocean Ridges
Where Stage 1 Crust is Made
Youthful Oceanic Crust
Basalt – Rock Typeof the OceanicCrust
Remember:Melting the mantle makesmafic magma!! Always
Continental Rifting The creationof new ocean basins
The Break-up of Pangea
200 Ma
125 Ma 75 Ma
Convergent Boundaries Making 2nd Stage Crust
Ancient Continental Crust
Convergent Boundaries- Where the Action Is!!
Ocean-Continent
Continent - Continent
Ocean - Ocean
Earthquakes
Volcanoes
Mt. St. HelensMay 18, 1980
Consequences of ConvergenceExplosive Volcanism
Consequences of ConvergenceMountain Building and Rock Deformation
Consequences of ConvergenceEarthquakes
Banda Ache, Dec. 26, 2004
OROGENESISThe Culmination of Convergence
San Francisco EarthquakeApril 18, 1906 Mag 7.8Transform
Boundaries
Mantle
Hotspots
Creation of overthickened oceanic crust
Famous Hotspots
Hawaii
Yellowstone?
Iceland