Chapter 17 Plate Tectonics Flashcards
Continental drift
The hypothesis that all continents had once been joined but drifted apart
Pangaea
The big connected continent thing in the hypothesis of continental drift
Magnetometer
A device that detects tiny changes in magnetic fields
Paleomagnetism
The study of the magnetic record contained by minerals with iron components
Magnetic reversal
When the earth’s magnetic field changes
Isochron
A line on a map that connects points with the same age
Seafloor spreading
The theory that new ocean crust is formed at ocean ridges and destroyed in ocean trenches
Theory of plate tectonics
Theory that says earth’s crust and rigid upper mantle are broken up into a bunch of slabs called plates. Widely accepted by scientists.
Divergent boundary
A place where two tectonic plates are moving apart
Rift Valley
When the continental crust starts to separate and forms a long, narrow valley thing, this is the valley thing
Convergent boundary
Opposite of a divergent boundary. A point where two tectonic plates are moving toward each other.
Subduction
Where a oceanic plate descends below another plate…never to be seen again (or probably so)
Transform boundary
A point where two tectonic plates slide horizontally past each other.
Ridge push
Where the weight of a ocean ridge pushes an oceanic plate towards a trench formed by subduction
Slab pool
Where the weight of a subducting plate helps it get pulled deeper faster
