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Magma. Composition of Magma. Slushy mix of molten rock, gases, and mineral crystals Elements in magma include: Oxygen, Silicon, Aluminum, Iron, Magnesium, Calcium, Potassium, and Sodium. Most abundant molecule is Silica. Formation of Magma.
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Composition of Magma • Slushy mix of molten rock, gases, and mineral crystals • Elements in magma include: • Oxygen, Silicon, Aluminum, Iron, Magnesium, Calcium, Potassium, and Sodium. • Most abundant molecule is Silica.
Formation of Magma • Temperature, Pressure, water content and mineral composition effect magma formation. • In the laboratory most rocks melt between 800-1200 degrees Celsius. • Increasing pressure raises the melting point • Increasing water content lowers the melting point. http://videos.howstuffworks.com/hsw/17137-whats-inside-the-earth-magma-inside-the-earth-video.htm
Types of magma • Basaltic Magma • Formed in upper mantle, low silica and gas content, low viscosity. • Andesitic Magma • Formed when oceanic crust is subducted into mantle, medium silica and gas content, intermediate viscosity. • Rhyolitic Magma • Formed when molten rock mixes with silica and water rich continental crust, high viscosity, large volume of trapped gases. http://videos.howstuffworks.com/hsw/6186-mountains-of-fire-lava-video.htm
Viscosity • Internal resistance to flow. • Ex. Honey, liquid soap, motor oil have higher viscosity than water, vinegar or gasoline.