Features Of Plate Margins Flashcards Preview

Geography - Tectonics > Features Of Plate Margins > Flashcards

Flashcards in Features Of Plate Margins Deck (11)
Loading flashcards...
1

What features occur at constructive plate margins? (Features tectonics)

•mid-oceanic ridge
•volcanoes
•Rift Valley

2

What does sea floor spreading cause at constructive plate margins? (Features tectonics)

1) mid-oceanic ridge = an underwater mountain range

2) volcanoes = magma rises between the diverging plates

3

What does continental rifting cause at constructive plate margins? (Features tectonics)

1) rift valleys = parts of the crust form parallel faults

2) volcanoes = magma rises between the diverging plates

4

What does features form at conservative plate margins? (Features tectonics)

Crustal faulting = plates slide past each other, pressure builds to stress, eventually released into an earthquake

5

What features form at continental-continental destructive plate margins? (Features tectonics)

Fold mountains = when two continental plates meet, sediment accumulates through the force one has on the other, moving upwards

6

What features form at oceanic-continental destructive plate margins? (Features tectonics)

1) deep ocean trenches = oceanic plate is denser so subducts and is pulled down forming a trench

2) volcanoes = the deeper a plate is pushed, the hotter the surroundings. Heat generated by friction causes the plate to melt in the Benioff zone. Molten material is less dense so rises

7

What features form at oceanic-oceanic destructive plate margins? (Features tectonics)

1) deep ocean trenches = oceanic plates build up tension, eventually one gives in and subducts

2) island arcs = magma rises to the surface of the ocean floor forming a line of volcanoes

8

What are hotspots formed by? (Features tectonics)

An area or concentrated radioactive decay in the core heats above (lower mantle) creating strong localised thermal currents, causing a magma plume

9

What happens when the magma plume from a hotspot reaches the crust? (Features tectonics)

Crust melts, forming active volcanoes - eventually convection currents move these away and more form

10

Where do hotspots occur and what is an example? (Features tectonics)

•In the middle of plates, far away from the boarder
•Hawaii - middle of the Pacific plate

11

Where do earthquakes occur and why? (Features tectonics)

At any boundary because the plates are moving