Plate Tectonics

What do the locations of Volcanoes and Earthquakes tell us?

Plate Tectonics Greek – “tektonikos” of a builder Pieces of the lithosphere that move around Each plate has a name Fit together like jigsaw puzzles Float on top of mantle

Continental Drift Alfred Wegener Continents were once a single land mass that drifted apart. Called this supercontinent Pangea, Greek for “all Earth” Could we use today’s maps 50,000 years from now? Why or Why not?

Evidence of Pangea

Landforms – Mtn. Ranges in N. America are made of same rock as European Mountain Ranges. Geology – Matching geologic trends between east coast of S. America, N. America, and Africa Fossil – Same organisms were found in S. America, Africa, India, and Australia

Tectonic Plates

Sea Floor Spreading

Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins Magma rises to the surface and solidifies and new crust forms Older Crust is pushed farther away from the ridge

How Plates Move