Solid Earth Geophysics Ali Oncel [email_address] Department of Earth Sciences KFUPM Today’s class: Plate Motions Reading: Fowler Chapters 2-3 http://neic.usgs.gov/neis/plate_tectonics/plates.html
OVERVIEW: PLATE TECTONICS Basic concept: The outermost layer ( LITHOSPHERE ) is divided in a small number of “rigid” plates in relative motion one respect to the other. It FLOATS on the weak ASTHONOSPHERE .
As a result of DISCOVERY, the plates are made up of both oceanic and continental material, whereas the ONLY oceanic parts of plate are created or destroyed. However, it is hard to understand why continental material usually is not destroyed at convergent plate boundaries.
Sea floor spreading at the mid ocean ridges produces only oceanic lithosphere.
From: Fowler, the solid Earth
How many plates? What is the largest plate and smallest plate?