2 The lithosphere is divided into separate sections called plates. The plates carry continents and ocean crust or both.
3 A Theory of Plate Motion J.Tuzo Wilson, a Canadian scientist, combined sea floor spreading, Earth’s plates and continental drift into a single theory.Scientific theory is a well tested concept that explains a wide range of observations.Plate tectonics is a theory that states the pieces of Earth’s lithosphere are in constant slow motion driven by convection currents in the mantle.
4 Plate Tectonic Theory explains the formation, movement, and subduction of Earth’s plates. PLATE BOUNDARIES:The edges of different pieces of the lithosphere meet at lines called plate boundaries.Faults- breaks in Earth’s crust, form at boundaries.
5 There three types of plate boundaries: Transform, Divergent, and Convergent.
6 Transform BoundariesA place where two plates slip by each other, moving in opposite directions.Earthquakes occur at these boundaries.
7 Divergent Boundaries The place where two plates move apart or diverge. When a divergent boundary occurs on land a Rift Valley, a deep valley, occurs.
8 Convergent BoundaryThe place where two plates come together, or converge.When two plates collide, the plate that is most dense will sink beneath the other.
9 The Continents Slow Dance The plates move from about one to ten centimeters a year.The North American and the Eurasian plates move about 2.5 cm. a year.