| A | B |
|---|
| Thickest Layer of the Earth | Mantle |
| Thinnest layer with large amounts of silicon and aluminum | Earth's crust |
| Movements mainly in the Earth's crust describe | Plate tectonics |
| Layer of the Earth with the greatest pressure, density and temperature | Inner Core |
| Inner core of the Earth is solid because... | the pressure from the outer core, mantle, and crust compresses it |
| Convection currents cause the Earth's crust to move because... | Earth's mantle hot material rise to the top of the mantle, cools, then sinks, reheats and rises again, constantly repeating the cycle |
| The Earth's crust... | is the least dense layer |
| The Inner Core... | most dense layer |
| Evidence that the continents were joined together at one time | Identical rock types, fossils, similar mountain ranges found on different continents separtated by oceans |
| Where do most geologic events take place? | the boundary of tectonic plates |
| Which type of boundary do tectonic plates move apart? | Divergent |
| Volcanoes form.... | where techtonic plates meet other plates |
| The plates that cover Earth's surace... | are always slowly moving |
| Seafloor spreading | magma rises, cools and spreads as more magma rises up from the mid-ocean ridge creating new crust |
| Mountain forms.... | when two continetal plates collide |
| Earthquakes most likely occur | where tectonic plates slide past one another |
| Volcanos | mountains that form when layers of lava and ash erupt and build up |
| subduction zone | oceanic plates are pushed down into the upper mantle |
| Earthquakes are caused when... | lithospheric plates move; rock layers bend and change shape; rock layers break due to enormous stress |
| Causes of trenches, volcanic islands and mid-ocean ridges | tectonic plate movement |
