What are Igneous Rocks? "Igneous" is derived from the Latin word for “fire” - ignis. Thus, rocks that are “fire-formed”: molten rock (magma) cools to form a solid rock
What is magma?
Magma is molten rock, and contains:
|Liquid, composed of mobile ions||Silicate minerals that have already crystallized from the melt||gases dissolved in the melt, including water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)|
How is magma made?
- Friction in subduction zones
- Crustal rocks heated during subduction
- Rising, hot mantle rocks
- Increase confining pressure, increase temperature required to melt rock.
- Decrease pressure, decrease the temperature
- Rock can melt at a lower temperature
- Lowers the temperature required to melt rock
- Primarily water
- Where would you find this?
How does magma get to the surface?
|Rocks at great depth||Rocks near the surface|