Continental Drift Theory
all the continents drift apart from one another over millions of year at a centimeter a year
Pangea
First full land mass huge land mass
Laurasia and Gonieanaland
2 huge land masses after Pangea broke apart
Composition of the Earth
Crust
Mantle
Core
Physical layers
Lithosphere
Asthenosphere
Plate tectonics
Upper mantle and crust are broken into sections called plates. These plates move around like a raft on the lower mantle
Lithosphere
Crust and upper layer of the mantle
less dense than the Asthenosphere.
100 km thick (250 miles)
Asthenosphere
Plastic layer- liquid layer
Plates
Ocean Plates- Plates under the ocean
Continental Plates-
Boundaries
Divergent (Rifting)- plates moving apart from each other
Convergent- plates moving together
Continental- Oceanic- Ocean plate goes under the continental plate
Oceanic- Oceanic- Pressure causes one plate to go down creating a hot spot
Continental- Continen
Mountains
Folded
Fault-block
volcanic
Unwarped
Folded Mountains
Two plates collide and the edges crumble
Consisted mainly of sedimentary rocks like limestone and shale
Fault- Block Mountains
Plate hits the fault and tips upside down
Volcanic Mountains
Made when volcanoes erupt and the lava coolest and builds up
Takes place where two plates collide
Made of basalt and rhyolite
Unwarped Mountains
Plates collide and they push up into a dome shape
Erosion causes the peaks and mountains
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