6th Grade Ch. 1 Sec. 5 Theory of Plate Tectonics

Ch. 1 Sec. 5 Theory of Plate Tectonics

Earth’s Lithospheric Plates

separate sections that the lithosphere is broken into

platesplates

Plate Tectonic TheoryPlate Tectonic Theory• geological theory• states that pieces of Earth’s lithosphere

are in slow, constant motion• driven by convection currents in mantle

The continents fit together like pieces of a jigsaw puzzle.

Plates moving animation

3 kinds of plate

boundaries

1. Transform boundary

2. Divergent boundary

3. ConvergentBoundary

Types of Plate BoundariesTypes of Plate Boundaries

1. transform boundary

• 2 plates slip past each other

• move in opposite directions

• earthquakes occur frequently here

transform boundary

2. divergent boundary

• 2 plates move apart

• most occur @ mid-ocean ridge

• when on land- forms rift valley

divergent boundary

3. convergent boundary

• 2 plates converge (come together)

• result= collision

• density determines which plate comes out on top

convergent boundary

• 225 million years ago-

Pangaea began to break apart

transform boundary

• 2 plates slip past each other

• move in opposite directions

• earthquakes occur frequently along these boundaries

convergent boundary

• 2 plates converge (come together)

• result= collision

• density determines which plate comes out on top

divergent boundary

• 2 plates move apart

• most occur at mid-ocean ridge

• when on land- forms rift valley

separate sections that the lithosphere is broken into

platesplates