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Flashcards in Plate Margins Deck (14):
1

Destructive

Cont-ocean

Ocean-ocean

Cont-cont - Collision boundary

2

Constructive

Submarine divergence

Continental divergence / rifting

Passive plate margin

3

Destructive ;
Cont-oceanic

Denser oceanic crust subducted

Friction and heat causes partial melting in the crust

Magma is less dense than the mantle
=forces itself through fissures in the lithosphere

4

Destructive ;
Cont-oceanic

LANDFORMS + HAZARDS

forms FOLD MOUNTAINS from rock that's scraped off descending/falling plate
^^^folding continental crust
DEEP OCEAN TRENCHES

causes VIOLENT VOLCANOES (composite cone) because of its VISCOUS ACIDIC LAVA that blocks the vents in the volcanoes
POWERFUL EARTHQUAKES AND TSUNAMIS

5

Destructive ;
Ocean-ocean

2 plates with an oceanic crusts COLLIDE with the DENSEST CRUST SUBDUCTING

6

Destructive ;
Ocean-ocean

LANDFORMS + HAZARDS

forms DEEP OCEAN TRENCHES
ISLAND ARCS as volcanoes that rise out the sea

causes VIOLENT VOLCANOES
VIOLENT EARTHQUAKES
SUBMARINE VOLCANOES that form to eventually become VOLCANIC ISLANDS

7

Destructive ;
Cont-cont - Collision Boundary

with the subduction of an oceanic crust happening, 2 continental plates are brought together

NONE CAN BE SUBDUCTED as they're of similar densities

8

Destructive
Cont-cont - Collision Boundary

LANDFORMS + HAZARDS

forms YOUNG FOLD MOUNTAINS
^^^^^ sedimentary rocks are scraped off the old sea floor to be compressed together to form these young fold mountains
*they grow and form despite the erosion they face

causes POWERFUL EARTHQUAKES

9

Constructive
Submarine divergence

plates MOVING AWAY FROM EACH OTHER
^^^^causes crust to weaken
^^^^hot magma forced upwards to CREATE A RIDGE

the RIDGE CENTRE can create a VALLEY where the crusts subsides into the magma below
these FISSURES/SPLITS in the crust provides a route for the more fluid lavas to escape

10

Constructive
Submarine Divergence

LANDFORMS + HAZARDS

the RIDGE CENTRE can create a VALLEY where the crusts subsides into the magma below
these FISSURES/SPLITS in the crust provides a route for the more fluid lavas to escape

forms MID OCEAN RIDGES
VOLCANIC ISLANDS

causes VOLCANOES with RUNNY BASIC LAVA
^^^ more frequent and less violent eruptions
SHALLOW FOCUS EARTHQUAKES

11

Constructive
Rifting / Continental Divergence

when spreading and pulling apart occurs beneath the continents

magma rising fractures and rifts

RIFT VALLEYS form as central sections collapse

VOLCANOES form where magma is forcibly rising through fissures

12

Constructive
Rifting / Continental Divergence

LANDFORMS + HAZARDS

forms RIFT VALLEYS - can widen + flood from the sea
VOLCANOES

causes VOLCANOES
SHALLOW FOCUS EARTHQUAKES

13

Constructive
Passive Plate Margin

plates moving parallel to each other
NO COLLISION OR SUBDUCTION

erratic movement because plates STICK TOGETHER - build up pressure and released all of a sudden

14

Constructive
Passive Plate Margin

LANDFORMS + HAZARDS

forms FAULT LINES (San Andreas)

causes POWERFUL EARTHQUAKES