Plate Techtonics Flashcards
Scientist that discovered the continents were once a supercontinent.
Wegener
Theory that the continents were once a supercontinent and began to separate millions of years ago.
Continental Drift Theory
The name given to the once supercontinent.
Pangaea
Wegener could not explain his hypothesis of exactly what made the continents move.
True or False
True
Evidence of continental drift which several
fossil organisms found on different landmasses.
Fossil Evidence
Evidence of continental drift that proves that the continents once fit together perfectly. Another name for Pangaea.
Continental Puzzle.
Evidence of continental drift that includes several mountain belts that end at one coastline, only to reappear on a landmass across the ocean.
Rock Evidence
Evidence of continental drift includes several shows glacial deposits and ice sheets covered large areas of the Southern Hemisphere millions of years ago.
Glacier Evidence
Theory in which the uppermost mantle, along with the overlying crust, moves as a strong, rigid layer called the lithosphere.
Plate Tectonics Theory
One of numerous rigid sections of the lithosphere that move as a unit over the material of the asthenosphere.
Plates
The place where two plates move apart. Add to the lithosphere
Divergent Boundary
Form where two plates move together. Destroy the lithosphere.
Convergent boundary
Two plates grind past each other without the production or destruction of the lithosphere.
Transform Fault Boundary
Part of divergent plate boundaries that are
continuous elevated zones on the floor of all major ocean basins.
Ocean Ridges
Deep faulted structures found along the axes of divergent plate boundaries.
Rift Valley
Production of new oceanic lithosphere on divergent plate boundaries.
Seafloor Spreading
When spreading centers develop within a continent, the landmass may split into two or more smaller segments
Continental Rift
Occurs when one oceanic plate is forced
down into the mantle beneath a second plate.
Subduction Zone
What are the 3 types of convergent boundaries?
Oceanic - Continental
Oceanic - Oceanic
Continental - Continental
A denser oceanic slab that goes under the continent and sinks into the asthenosphere that causes pockets of magma to develop and rise to surface causing volcanic eruptions.
Ex Andes Mt.
Oceanic - Continental
Form in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent. Land Volcanoes.
Continental Volcanic Arc
Two oceanic slabs converge, and one descends beneath the other which develops volcanoes on the ocean floor.
Ex Hawaiian Islands
Oceanic - Oceanic
Form as volcanoes emerge from the
sea.
Volcanic Island Arc
Occurs when subducting plates
contain continental material, two continents collide, which can produce new
mountain ranges, such as the Himalayas, Alps and Appalachian.
Continental - Continental
An example of a transform fault boundary.
San Andreas Fault
The natural remnant magnetism in rock bodies which is used to determine the location of the magnetic poles at the time the rock became magnetized.
Paleomagnetism
When rocks show the same magnetism
as the present magnetism field.
Normal Polarity
When rocks show the opposite magnetism
as the present magnetism field.
Reverse Polarity
A concentration of heat in the mantle capable of producing magma, which rises to Earth’s surface and forms landmasses as the plate moves.
Hotspots
The motion of matter resulting from changes in temperature.
Convection Flow
A mechanism that contributes to plate motion in which cool, dense oceanic crust sinks into the mantle and “pulls” the trailing lithosphere along.
Slab Pulls
Causes oceanic lithosphere to slide down the sides of the oceanic ridge under the pull of gravity. It may contribute to plate motion.
Ridge Push
Are masses of hotter-than-normal mantle material that ascend toward the surface, where they may lead to igneous activity.
Mantle Plums
