Plate tectonics
Internal structure
Crust
upper mantle
astenosphere
oceanic
continental
Lithosphere
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Lower mantle
Older - 3.5 billion
Younger- 300million
sea floor spreading, pangea
pangea was 300million began breaking
Top section
35km on average
2.7
2.9
mantle
peridotite
sedimentary metomorphic =granitic
basalt
when it melts it can make basalt
outer core
liquid
iron and nickle
inner core
solid
iron nickle
lots of pressure and carbon
500 degrees
5000
heat comes from residual heat and radioactivity
Plate movement
convection currents
slab pull
gravity slide
the subducting heavy oceanic plate pulls another plate down with it colder and denser
mainly oceanic
major force of plate movement
heat comes up cuases the crust to bulge then the gravity pulls them down but can't go straight down so it slides downhill like. arock on a hill
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They operate together
evidence for plate tectonics
continental drift
fossil
jigsaw split
rocks mountain ranges
glacial deposits
plants
artic
plate tectonics
sea floor spreading
ocean ridges
paleomagnetism
molten coms up magnetic material aligns wit the pole at the time and it goes nsnsns symetrical eitherside of the plate boundaries
rocks get older aswell
constructive is warmer
plate boundaries
constructive
collusion
destructive
conservative
convection current comes up to the central rift valley
folding
faulting