Plate tectonics Flashcards
Lithosphere
The solid, outer layer pf the earth that consists of the crust and the rigid upper part of the mantle
Asthensphere
the soft layer of the mantle on which the tectonic plates move
mesosphere
The strong, lower part of the mantle between the asthenosphere and the outer core.
Inner core
the innermost geologic layer of planet Earth. It is primarily a solid ball with a radius of about 1,220 km
Outer core
a fluid layer about 2,400 km thick and composed of mostly iron and nickel that lies above Earth’s solid inner core and below its mantle
Seismic waves
a wave of energy that travles through the earth and away from an earthquake in all directions
Oceanic crust
the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates
Continental crust
the relatively thick part of the earth’s crust that forms the large landmasses. It is generally older and more complex than the oceanic crust
Density
the ratio of the mass of a substance to the volume of the substance
Alfred wegener
a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
Continental drift
the hypothesis that states that the continents once formed a single land mass between the shoreline and the continental slope.
convergent boundary
the boundary formed by the collision of movement of a liquid or gas.
Divergent boundary
the boundary between tow tectonic plates that are moving away from each other
Transform boundary
the boundary between tectonic plates that are sliding past each other horizontally.
Sea floor spreading
the process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies.
Pangaea
a supercontinent that existed during the late Paleozoic and early Mesozoic eras.
Laurasia
the more northern of two large landmasses that formed part of the Pangaea supercontinent from around 335 to 175 million years ago, the other being Gondwana
gondwana
a supercontinent that formed during the late Neoproterozoic and began to break up during the Jurassic, with the final stages of breakup, including the opening of the Drake Passage separating South America and Antarctica occurring during the Paleogene
mesosaurus
an extinct small aquatic reptile of the early Permian period, with an elongated body, flattened tail, and a long, narrow snout with numerous pointed teeth.
. Glossopteris
the largest and best-known genus of the extinct Permian order of seed ferns known as Glossopteridales.
