Plate Tectonics
SOL 4
Fundamental Concepts and Skills
1. The earth consists of a core, mantle, and crust, which are
dynamic systems, constantly in motion.

Core- mostly iron inner core, which is a liquid and a solid mostly
iron outer core a rocky, plastic mantle; and a rocky, brittle crust.

Mantle- rocky, plastic

Crust- rocky, brittle solid
2. The lithosphere is the solid outer shell of Earth. It is divided into
plates that are in motion with respect to one another.
3. There are two different types of crust (oceanic and
continental) that have very different characteristics.

Ocean crust is relatively thin, young and dense.

Continental crust is relatively thick, old, and less dense.
Reading
Chapter 8
Chapter 8
Chapter 8
4. Plate motion occurs as a consequence of convection in the
mantle.

Convection is a current that is set up when hot, less dense
material rises, cools, becomes denser, and sinks.

Continental drift is a consequence of plate tectonics.
4. Most geologic activity (e.g., earthquakes, volcanoes, and mountain
building) occurs as a result of relative motion along plate boundaries. Hot
spot volcanic activity is exceptional in that it is NOT related to plate
boundaries.
5. There are three types of plate boundaries:

convergent (subduction and continental collision)

divergent (sea-floor spreading)

transform
6. Major features of convergent boundaries include collision zones (folded
and thrust-faulted mountains) and subduction zones (volcanoes and
trenches).
7. Major features of divergent boundaries include mid-ocean ridges, rift
valleys, and volcanoes.
8. Major features of transform boundaries include strike-slip faults.
Chapter 8
Chapter 8