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| Why are the first minerals to crystalize the last to melt when the rock is heated? | Because it takes such a high temperature to be melted as soon as it cools it crystalizes inside it doesnt take as high of temperature to stay molten |
| What is the diffrence between extrusive and in trusive rocks? | Extrusive-fine grained, cool quickly on earths surface
Intrusive-coarse grained, cool slowly, beneath earths surface |
| How do temperature and pressure change as a mass of magam moves upward through the Earths crust? | Temperature and pressure decrease |
| What are 3 ways magma is classified? | Basaltic-least amount of silica
Andesitic
rhyolitic-most silica |
| What is the classification of magma based on? | amount of silica it contains |
| Why are there diffrent types of an igneous rock | diffrent grain sizes |
| What is fractional crystalization | when magma cools diffirent minerals form at diffrent temperatures |
| what determines texture? | rate of cooling determines shape of grains which is texture |
| How do you check texture? | BY making thin slice and looking under a microscope |
| State 1 reason why igneous rocks are resources? | minerals found in in them are resistant to weathering |
| what is most common igneous rock? | granite |
| what is magma made of (3 things)? | molten rock, gases, mineral crystals |
| how does silica affect magma(2 things) | 1. melting temp 2. quickly magma flows |
| HOw are Igneous rocks classified? | extrusive and intrusive |
| What so felsic rocks look like? | light colored, high silica content, contains quartz |
| what do mafic rocks look like? | dark colored, lower silica content, and rich in iron and magnesium |
| Do felsic or mafic rocks have higher silica content? | felsic |
| what size crystals form when magma cools slowly? | large |
| what size crystals form when lava flows quickly? | small |
