12. Drifting Continents: Plate Tectonics Flashcards Preview

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Flashcards in 12. Drifting Continents: Plate Tectonics Deck (32)
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1
Q

pangaea

A

the supercontinent formed about 300 million years ago by the fusion of all continents

2
Q

panthalassic ocean

A

the single large ocean that surrounded Pangaea 300 million years ago

3
Q

Laurasia

A

a landmass that resulted when Pangaea split about 200 million years ago, which consisted of modern day North America, Greenland, and Eurasia

4
Q

Gondwana

A

a landmass that resulted when Pangaea split about 200 million years ago, which consisted of modern day South America, Australia, Africa, India, and Antarctica

5
Q

continental drift

A

a theory proposed by Alfred Wegener stating that continents move slowly across earth’s surface

6
Q

plate tectonics

A

a theory addressing the origin, movement, and recycling of lithospheric plates and the landforms that result

7
Q

subduction

A

the process in which oceanic lithosphere bends and dives into the mantle beneath another lithospheric plate

8
Q

plate boundary

A

the margin of a lithospheric plate

9
Q

ridge push

A

the process by which magma rising along a mid-ocean ridge forces oceanic crust of two seperate plates apart

10
Q

mantle drag

A

the dragging force between the asthenosphere and the overlying lithosphere

11
Q

slab pull

A

the process by which the weight of subducting oceanic lithosphere accelerates plate movement by pulling the plate deeper into the mantle

12
Q

divergent plate boundary

A

a region where two lithospheric plates move apart

13
Q

convergent plate boundary

A

a region where two lithospheric plates move toward each other

14
Q

transform plate boundary

A

a plate boundary where one lithospheric plate slips laterally past another

15
Q

rift

A

a region where continental crust is stretched and splitting

16
Q

rift valley

A

a linear valley with volcanoes formed by rifting of continental crust, sometimes filled with freshwater to form a deep lake

17
Q

Wadati-Benioff zone

A

a sloping pattern of increasingly deep earthquake foci found in a subduction zone

18
Q

continental volcanic arc

A

a long chain of volcanoes formed on the margin of a continent above a subducting plate

19
Q

volcanic island arc

A

a chain of islands formed where oceanic lithosphere of one plate is subducting beneath oceanic lithosphere of another plate

20
Q

Pacific Ring of Fire

A

a zone of volcanically active mountain chains resulting from subduction on the margins of the Pacific Ocean

21
Q

collision

A

convergence of the continental crust of two different plates

22
Q

accreted terrane

A

a mass of crust that is transported by plate movement and fused onto the margin of a continent

23
Q

active continental margin

A

a margin of a continent that follows a plate boundary, typically characterized by a deep-sea trench and a narrow continental shelf

24
Q

passive continental margin

A

a margin of a continent that does not coincide with a plate boundary, typically characterized by a broad, sloping continental shelf

25
Q

hot spot

A

a location at the base of the lithosphere where high temperatures cause the overlying crust to melt

26
Q

mantle plume

A

a mostly stationary column of hot rock that extends from deep in the mantle up to the base of the lithosphere

27
Q

fold

A

a wrinkle in the crust resulting from deformation caused by geologic stress

28
Q

fault

A

a fracture in the crust where movement and earthquakes occur

29
Q

anticline

A

a fold in the crust with an archlike ridge

30
Q

syncline

A

a fold in the crust with a U-shaped dip

31
Q

orogenesis

A

mountain building

32
Q

orogenic belt

A

a linear mountain range