plate tectonics drives 2 stages of crust-making 1. mantle partially melts to make ocean crust

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