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Plate tectonics
Question | Answer |
---|---|
Continental crust | Thicker but less dense |
Oceanic crust | Thinner but more dense |
What are the driving forces behind plate tectonics | Convection currents in the mantle and plasticity in the mantle |
What types of stress do convergent, divergent, and transform boundaries create | Convergent-compression Divergent-tension Transform-shear |
Land features of a transform boundary (1 example) | Slip faults and earthquakes (San Andreas fault line) |
Where are divergents boundaries most common | C-C and O-O |
At divergent O-O is crust created or destroyed | Created |
At divergent C-C is crust created or destroyed | Neither |
Description of divergent O-O boundary and land features formed (1 example) | Sea floor spreads and magma comes up and cools, mid ocean ridges are formed (mid Atlantic ridge) |
Description of divergent C-C boundary and land features formed (1 example) | 2 plates move away from each other but magma doesn’t break through, rift valleys are formed (great Rift Valley) |
Where are convergent boundaries found | C-C, C-O, and O-O |
At which types of convergent land is new crust created or destroyed | O-O and C-O the oceanic is destroyed but at C-C neither happens, it reshapes |
Description of convergent O-O and land features formed(1 example) | 2 plates come together and one gets sub-ducted/destroyed, trenches and volcanic island arcs are formed(Mariana trench) |
Description of convergent C-O and land features formed(1 example) | Oceanic plate is sub-ducted, making trenches and volcanic mountains(Andes mountains) |
Description of convergent C-C and land features formed(1 example) | Neither plate sink, both push up creating folded mountains(Himalayan mountains) |