| A | B |
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| List 5 types of evidence for plate tectonics | fit of continents, same fossils on far apart continents, volcanoes/earthquakes usually occur at plate boundaries, similar geological features, paleomagnetism |
| How are fossils used as evidence for plate tectonics? | The same fossils occur on continents that are thousands of kilometers apart...they could not have swam or flown that far, continents must have once been together. |
| What is paleomagnetism? | Rocks formed at mid ocean ridges record the orientation of the poles in their mineral grains....samples show North and South pole have reversed several times. |
| What climate evidence is there for plate tectonics? | Warm continents show evidence they were once covered by glaciers...this shows they were once at the south pole. |
| What is sea floor spreading? | At mid ocean ridges, plates are separating and hot magma is rising in between, cooling and forming ridges. |
| What drives sea floor spreading? | Convection currents in asthenosphere of mantle. |
| If magma is rising, what are the plates doing? | separating |
| If magma is sinking, what are the plates doing? | converging |
| List the layers of the earth in order (from inside to outside) | inner core, outer core, mantle, crust |
| Which layer is liquid? | Outer core |
| Describe the composition of the upper mantle. | Like thick toothpase, can sort of flow |
| What is the very upper part of the mantle called? | Asthenosphere |
| How is ridge push related to slab pull? | ridge push occurs at one end of a plate at the diverging boundary, the other end of the plate has slab pull at the converging boundary |
| A scientific research vessel notices a ridge in the middle of the ocean...what type of boundary is this likely to be and why? | a diverging boundary...new magma comes up between plates, cools and pushes the plates apart |
| A scientific research vessel notices a trench at the edge of the ocean...what type of boundary is this likely to be and why? | a converging (subduction) boundary...subducting plates create a v shapted trench |
