plate tectonics Flashcards
Lithosphere
the solid, outer part of Earth.
Asthenosphere
the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
Mesosphere
a layer of Earth’s atmosphere.
Inner Core
a hot, dense ball of (mostly) iron.
Outer Core
liquid, iron-nickel layer of the Earth between the solid inner core and lower mantle.
Seismic Waves
caused by the sudden movement of materials within the Earth, such as slip along a fault during an earthquake.
Oceanic Crust
the outermost layer of earth under the oceans.
Continental Crust
the layer of granitic, sedimentary, and metamorphic rocks, which form the continents and the areas of shallow seabed close to their shores
Density
the substance’s mass per unit of volume.
Alfred Wegener
German meteorologist and geophysicist
Continental Drift
the movement of the Earth’s continents relative to each other, thereby appearing to drift together across the oceanic bed.
Convergent Boundary
This occurs when plates move towards each other and collide.
Divergent Boundary
occurs when two tectonic plates move away from each other.
Transform Boundary
places where plates slide sideways past each other.
Sea-floor Spreading
a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other.
Pangaea
North America was contiguous with Africa, South America, and Europe.
Laurasia
ancient continental mass in the Northern Hemisphere that included North America, Europe, and Asia
Gondwana
one of the two ancient supercontinents produced by the first split of the even larger supercontinent Pangaea about 200 million years ago,
Mesosaurus
an extinct genus of reptile from the Early Permian of southern Africa and South America.
Glossopteris
a genus of chiefly Permian and Triassic fossil ferns or fernlike plants characterized by thick entire fronds with anastomosing veins.
