Wilson cycle, ridge push, slab pull, Active versus Passive Plate Tectonics

REVIEW

lithosphere

 asthenosphere

 mesosphere
 
 

DEFINITIONS

Wilson cycle

Professor Tuzo Wilson in 1966 noted that opening-closing cycles evolution of the proto-Atlantic Ocean could explain the geological history observed on the conjugate contintal margins

READINGS

 Ch. 6

LECTURE
 
 

WILSON CYCLE
 
 

It is now viewed that plates have repeatedly broken and reassembled every 400-500 Ma. Passive-to-Active breakup

 1: continental heating, doming and extension under body forces.

 2: seafloor spreading. Old rifted inactive margin - passive margin

 3: subduction

 4: continental collision and suturing
 
 

TYPES OF PLATE BOUNDARIES
 
 

ONCE PLATE TECTONICS GETS GOING:
 
 

1. divergent plate boundaries

 2. convergent plate boundaries

 3. transform plate boundaries
 
 

include slides and overheads