2 n 3: Plate tectonics & The Mantle Flashcards
What land forms occur at convergent boundaries?
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What land forms occur at divergent boundaries?
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Explain Mantle convection
Material that flow loose energy, as mantle is being heated from below it forms a convection which pulls colder upper mantles down as hotter mantle material rises and pulls the crust
What process occur at transform boundaries?
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Why does cretonic continental crust remain?
Very very old and thick, with deep roots into the mantle. Also very buoyant
What are plate driving forces?
Slab pull, dragging plates along. ridge push and Basal traction
What forms at spreading and subduction zones
Ridge push at spreading, trenches at subduction zones
Inner core and outer core made of
Solid iron-nickel metal
Molten iron-nickel and other metals
The mantle made of
Viscous
How do we know how deep the mantle is?
Measuring the reflected or refracted frequency of seismic waves
What are waves influenced by?
Density, Temp. and angles which they strike at
What is a mantle ploom
when convecting, matter from the outer core-mantle boundary will rise to the crust, due to instabilities during heating
What do bloom do?
Cause large eruptions in a row as the move across the curst or volcanoes
Xenoliths
Foreign rock meaning foreign mineral within the mantle
Asthenosphere
semi-rigid mid-mantle between the crust and the convecting mantle. Asthenosphere moves the crust
