Ch.2 - Plate Tectonics Flashcards
Divergent Boundaries
Plates move apart, creating new crust. Creates normal faults.
ex. mid atlantic ridge
Convergent Boundaries
Plates collide, leading to subduction. creates reverse faults.
ex. andes mountains
Transform boundaries
plates slide past each other. creates transform faults
ex. san andreas fault
Normal Fault
Occurs at divergent boundaries due to tension, where the hanging wall moves down.
Reverse fault
Occurs at convergent boundaries due to compression, where the hanging wall moves up.
Transform Faults
Characterized by horizontal movement; can be right-lateral or left-lateral.
ex. In a right-lateral fault, if you stand on one side, the opposite side appears to move to the right.
Continental Drift:
Theory that continents floated through the ocean base
Who popularized and explored the theory of continental drift?
Alfred Wegner
5 methods by which continental drift was proven:
- fit of continents
- living plants and animals
- fossil plants and animals
-related rock types
-reconstruction of ancient climates
Paleomagnetism
The study of the magnetic properties of rocks, which supports the theory of plate tectonics by showing historical magnetic orientations.
Polar wander
Stationary continents, but a historically moving magnetic pole
Declination
the angular east/west difference between the geographic and magnetic poles
What is the declination in New Paltz?
~15deg
Inclination
the angular north/south difference between the geographic and magnetic poles
Magnetic Dipole
Imaginary arrow that goes through the center of the earth that points to the direction that the magnetic field is flowing
