Download Plate Tectonics Review The rock at the Earth`s surface forms a

Plate Tectonics Review
The rock at the Earth’s surface forms a nearly continuous shell around earth called the lithosphere.
The lithosphere consists of the crust and the uppermost part of the mantle that floats on the “plastic”
asthenosphere.
Analysis of earthquake wave data (vibrational disturbances) leads to the conclusion that there
are layers within the Earth.
These seismic waves tell us that the layers (crust, mantle, outer core, inner core) have distinct
properties and composition.
The interior of the Earth is hot.
Convection currents- heat flow and movement of material within the Earth cause sections of
Earth’s crust to move. This may result in earthquakes, volcanic eruption, and the creation of
mountains and ocean basins.
Convection cells- within the mantle may the driving force for the movement of plates.
Folded, tilted, faulted, and displaced rock layers suggest past crustal movement.

The Earth is dynamic, constantly in motion.
Continents fitting together like puzzle parts and fossil correlations provide initial evidence that continents were once
together. The large landmass was known as Pangaea.
Continental Drift
Theory
Evidence: 1. Continents “fit!”
2. Fossils match up!
3. Rocks match up!
4. Landforms match up!
The Theory of Plate Tectonics explains how the solid lithosphere consists of a series of plates that float on the partially
molten section of the mantle (asthenosphere).
Most volcanic activity and mountain building occur at the boundaries of these plates, often resulting in earthquakes.
Plates may collide, move apart, or slide past one another.
An active chain of volcanoes at plate
boundaries is called the Ring of Fire.
Converging boundaries may have subduction taking place. The more dense crust (often oceanic) slides beneath
crust that is less dense. Seafloor spreading results in the creation of new crust.