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Igneous Processes
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Magma is molten rock inside the crust or upper mantle containing the chemicals which form the rock-forming
minerals that make up igneous rocks. Magma also contains volatiles, dissolved under pressure, which affect
the mobility of the magma and may cause volcanoes to erupt explosively.
As the magma rises through the crust, it may solidify before reaching the surface, leaving intrusions. If it reaches the surface, magma will form extrusions, more commonly known as lava and volcanoes. In areas where molten magma lies close to the surface, the geothermal gradient will be higher than normal, resulting in geothermal areas. Igneous rocks make up a significant proportion of the earth's surface, and show a miscellany of notable features and uses. It is possible to determine the age of an igneous rock by using radiometric dating. |
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- Magma and Igneous Rocks
- Intrusions
- Extrusions
- Geothermal Areas
- Miscellany
- Radiometric Dating
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