plate tectonics Flashcards
Lithosphere
the rigid outer part of the earth, consisting of the crust and upper mantle
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
the region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude
Inner Core
It is composed of an iron–nickel alloy and some other elements
Outer Core
Earth’s solid inner core and below its mantle. Its outer boundary lies 2,890 km (1,800 mi) beneath Earth’s surface
Seismic Waves
an elastic wave in the earth produced by an earthquake or other means
Oceanic Crust
the relatively thin part of the earth’s crust which underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments
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 degree of compactness of a substance
Alfred Wegener
During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research
Continental Drift
the gradual movement of the continents across the earth’s surface through geological time
Convergent Boundary
A convergent boundary is a type of boundary where two plates meet together and start to push against one another
Divergent Boundary
In plate tectonics, a divergent boundary or divergent plate boundary
Transform Boundary
A transform fault or transform boundary is a plate boundary where the motion is predominantly horizontal. It ends abruptly and is connected to another transform, a spreading ridge
Sea-floor Spreading
the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side.
Pangaea
continental units approximately 335 million years ago, and it began to break apart about 175 million years ago.
Laurasia
The large northern continent is called Laurasia and the southern continent is called Gondwanaland
Gondwana
a hypothetical landmass in the Southern Hemisphere that separated toward the end of the Paleozoic Era to form South America, Africa, Antarctica, and Australia. Compare Laurasia
Mesosaurus
is 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
