| A | B |
|---|
| crust (5-70 km thick) | Earths outmost layer made of solid, brittle rock |
| continental crust | made of a light rock called granite |
| ocean crust | made of a dense, dark rock called basalt |
| parts of the earth (4) | crust, upper mantle, lower mantle, outer core, inner core |
| mantle (2900 km) | Upper and lower mantle. |
| upper mantle (660 km) | molten rock contains iron, magnesium. It flows |
| lower mantle (2225 km) | solid dens tant contains magnesium and iron |
| outer core (2270 km) | liquid. Composed of iron and nickel |
| inner core (1200 km) | solid due to pressure. Iron and nickel |
| lithosphere | form the tectonic plates: crust and upper mantle |
| asthenosphere | .below the lithosp partly molten layer |
| why tectonic plates move? | due to convection currents in the mantle |
| spreading ridge | where magma flows out in the ocean |
| rift valley | if spreading occurs on land |
| ridge push | when magma rises and pushes old rocks and plates move |
| subduction | a plate pushing below another plate |
| what happens in subduction zones? | occurs volcanoes and earthquakes |
| slab pull | when the plates goes under puls the rest of the plate |
